1. BIOPLASTICSIn Search of Winning Technology
Plastics though versatile and useful in many applications cause
aesthetic, environmental issues. An attempt is required to find
alternatives or solution.
S. N. Jogdand
1/10/2014
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BIOPLASTICS
Chapter No. Contents Page No.
1 Plastics World 3
2 Problems of Plastic 10
3 Alternatives for Plastics 14
4 Worldwide Scenario of Bioplastics Market and Activity 20
5 Bioplastics – Properties and Processing 28
6 Bioplastics Standards 41
7 Polyhydroxy Alkonates as Bioplastics 51
8 Polylactic Acid as Bioplastics 65
9 Starch-based Bioplastics 77
10 Blends - Bioplastic-Synthetic 82
11 Bio-based Chemicals for plastics – Partial Solution 92
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Chapter 1
Plastic World
Introduction
The word plastic comes from the Greek word ‗plastikos‘, which means mouldable. Plastic is one
of the few new chemical materials, which pose environmental problem. Polyethylene, polyvinyl
chloride, polystyrene is largely used in the manufacture of plastics. According to an estimate
more than 100 million tonnes of plastic is produced every year all over the world. In India it is
only 2 million tonnes. In India use of plastic is 2 kg per person per year while in European
countries it is 60 kg per person per year while that in US it is 80 kg per person per year. Plastic
in the environment is regarded to be more an aesthetic nuisance than a hazard, since the
material is biologically quite inert. 20% of solid municipal wastes in US is plastic. Non-
degradable plastics accumulate at the rate of 25 million tonnes per year. These materials have
molecular weight ranging from several thousands to 1,50,000. Excessive molecular size seems
to be mainly responsible for the resistance of these chemicals to biodegradation and their
persistence in soil environment for a long time.
Synthetic polymers are easily molded into complex shapes, have high chemical resistance, and
are more or less elastic. Some can be formed into fibers or thin transparent films. These
properties have made them popular in many durable or disposable goods and for packaging
materials. Plastics can be divided into two main groups; thermoplastics and thermosets (stiff
and not elastic).
More than 128,000 companies operate in the plastics space. Due to the wide range of plastic
products manufactured, even the biggest players account for very small pieces of the pie.
Success in this industry depends on economies of scale, cost control; smart contract
management, quality control, and effective R&D. Economics in the plastics business are
particularly driven by the cost of feedstocks, primarily petroleum-based resins and recycled
materials. The business is highly competitive and capital-intensive. Barriers to entry are high,
presenting a challenge for the emerging bioplastics segment.
IBISWorld says 40.1 percent of plastics industry demand is in packaging. However, because
packaging goods are relatively low-cost, large-scale products, plastic containers and packaging
products account for only 14 percent of revenues in the plastics industry. Containers and
packaging do constitute a growing segment for plastics. In the plastic container industry, the two
primary segments are conventional plastic containers, such as those for drinks; and custom
containers that are manufactured according to specified characteristics such as heat tolerance
or air tightness. Plastics market is $779.8 billion.
Most commonly used polymers and their uses:
Sr. No. Polymer Resin Common Use
1 High Density Polyethylene (HDPE) Rigid containers
2 Low Density Polyethylene (LDPE) Package films, bags
3 Polypropylene (PP) Wrappers, linings, boxes, crates
4 Polystyrene (PS) Foams, insulations
5 Polyvinyl chloride (PVC) Rigid containers, films
6 Polyethylene terphthalate (PET) Soft drink containers
7 Polycarbonate (PC) baby bottles, sports water bottles
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Why Plastic is Popular?
1. Cheap
2. Durable
3. Disposable
4. Convenient for Packaging
5. Can be molded into Complex Shapes
6. Inert
7. Most Energy Efficient Option
8. Creates Least Air Emissions during Manufacturing
9. Produces Least Solid Waste by Both Weight and Volume (at equal container recycling
rates)
10. Packaging without plastics results in:
i. More packaging waste by weight -- more than 4 times greater
ii. More packaging waste by volume -- more than 2 1/2 times greater
iii. More energy used in manufacturing and distribution -- more than 2 times greater
iv. Higher cost of packaging -- more than 2 times greater.
According to several studies compiled by the Association of Plastics Manufacturers in Europe,
the use of plastics yields large energy savings.
To illustrate, a truckload of bottled water in glass bottles is comprised of 57 percent water and
43 percent glass by weight; while in plastic, the load is 93 percent water and 7 percent plastic.
The use of plastic results in an approximately 40 percent reduction in overall motor fuel
consumption and the associated exhaust emissions.
Properties of Plastics
1. Gloss (EPG‘s Depart (PVA based)
2. Transparency (Lacca (PLA based) of Mitsui Chemical)
3. Density – Usefulness in sedimentation in aquatic environment (PP – Low, PHB – High)
4. Transparency to UV – can cause chemical oxidation – PE – Transparent, Soya-based –
blocks UV)
5. Gas barrier properties – Important in food packaging (Good in gluten-based and PV-
based plastics)
6. Oxygen permeability of edible polymer films
7. Water vapor transmittance – (Resistance expected) Important in food packaging.
Minimum in PP and PS
8. Modulus Resistance to deformation (Low for starch, PHA) Blend with polymers fillers
9. Glass transition temperature (Temperature at which a polymer changes from hard and
brittle to soft and pliable form. (Important for processing) Mazin (PLA based High Tg)
10. Melting temperature – Important for procesability
11. Hydrophilicity or Water resistance – Important for disposable diapers and sanitary
napkins (PLA water resistant, Depart water soluble)
12. Flexural Strength – Needed to break the sample (Good in PP, PS, hard PLA, nylon,
Less in PE)
13. Hardness – Procesability affected
14. Antistatic properties – Suitable for electronic packaging
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Structures of commonly used Plastics
Market for Plastics in India
Per Capita consumption of plastic in India – 2kg/person/year
Per Capita consumption of plastic in developed countries – 60 kg/person/year
Per Capita consumption of plastic in US – 80-90kg/person/year
Per Capita consumption of plastic of world – 15kg/person/year
The projected demand for plastic in India is about 25 lakh tones/year by 2001.
20,000 processing units by 2000
Domestic demand for plastic is expected to cross 4 million tones by the year 2001-2.
Plastic 1-4% in solid wastes in India while in USA it is 30% of solid wastes
India is largest manufacturer of thin carry-bags and exports fetched Rs.32 crores. 8-10 micron
thickness plastic bags are made out of recycled plastics. With repeated recycling- strength
reduces, appearance becomes repulsive and there is no resale value.
1 kg of thin plastic bags = 1000 pieces, Milk bags – 25 micron thickness
Provision to ban plastic bags is in Section 5 of 1986 EPA.
Ban on plastic bags of < 20 micron thickness
Fine for individual violators – Rs.2000/- and vendors – Rs.1,50,000/-
Approximate Breakdown of the Global Plastic Production
Polyethylene terephthalate 6%
Polyethylene 40%
Polyvinyl chloride 20%
Polypropylene 19%
Polystyrene 9%
= Approximate Total 94%
The most commonly used types of plastics are PO, PP, PS, PVC, PET, PC, PU, polyacrylates,
polyvinyl acetates, and polyamides. These synthetic polymers are typically made from the
naphtha fraction of petroleum or natural gas; and are heavy pollutants as they are not
biodegradable. We are living in a "throw away" society and as a result, millions of tons of
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plastics end up in landfills, the ocean, and the shores. Even if this practice were to stop today,
plastic waste would continue to wash upon our shores for hundreds of years. This has
significantly eroded the marine life, as millions of marine animals die each year; and there is
clear evidence that this trend will escalate because the global thirst for these materials is on the
rise.
The use of plastics in our everyday life is nearly boundless. Due to its low cost of production and
versatility, no alternate emerging product is likely to replace the nearly ubiquitous presence of
plastics. The current global production level is about 250 million tons and its growth will continue
to be robust globally. Plastics are preferred as they are light, durable, resist deterioration, and
the markets they cater to are extensive: food, textiles, furniture, electronics, vehicle parts,
photography/videography, coatings, construction, enclosures, bottles/containers, and many
more.
The common reason these plastics are produced in such abundance is price. These plastics
can be used in many applications, often with superior properties, for a lower cost then other
materials or plastics that could be used in the same application.
Properties and Applications of 5 Main Types of Plastics
No. Type of
Plastic
Properties Applications
1 Polyethylene Available in different densities -
Available as LDPE and HDPE
good toughness,
excellent chemical resistance,
near zero moisture absorption,
and good ease of processing.
The low glass transition
temperature of -110o
C will allow
good retention of mechanical
properties, even at low
temperatures.
The service temperatures of
polyethylene range from -40o
C
to 93o
C.
Low-density Polyethylene
(LDPE) is a relatively soft
form of PE. It is commonly
used in trash bags, food
packaging, grocery bags, dry-
cleaning bags, and squeeze
bottles.
LDPE is also used to make
diaper liners and agricultural
covers.
High-density Polyethylene
(HDPE) is commonly used in
milk containers, lids, laundry
detergent containers, and
other durable containers.
HDPE is also used to make
sporting goods, electrical
insulation, and toys.
2 Polyvinyl
Chloride (PVC)
It can be processed by more
techniques.
Low cost of production
Moderate heat resistance
Good toughness
Can be produced from flexible to
rigid grades.
They have excellent water and
chemical resistance and good
strength.
PVC are used as packaging
materials for food and drugs
because they are nontoxic,
odorless, and tasteless.
They are also used for
decorative packaging for
products requiring only an
ordinary amount of protection,
as well as for common items
such as credit cards.
These plastics can also be
used in printing inks and can
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be effectively used in coating
paper and sometimes other
plastics.
Another application is in
construction, where the rigid
form is used for pipes and rain
gutters. In general, polyvinyl
chlorides can be produced
with a wide range of hardness
ranging from thin, flexible
films to rigid molded pieces by
adding different plasticizers in
the production process.
3 Polypropylene Extremely versatile
Available in many grades
It is used in the packaging
industry for packaging, food
containers, and bottles.
It is also used for luggage,
molded parts for automobiles,
and household appliances.
4 Polystyrene Easy to process
Relatively low cost
Found in many grades
Competes with expensive
plastics
Basic polystyrene is brittle
Used in food packaging, lids,
meat trays, as well as cookie
and candy packages.
An expanded version of
polystyrene, named
Styrofoam, is used for
many things including take-
out containers, fast food tubs,
egg containers, and is used
as a filler for the shipping
industry to pad items in
transport. It is also used
outside of packaging industry
for shower doors, toys, and
disposable kitchenware.
5 Polyethylene
Terrapthlate
(PET)
Broad range of mechanical
properties
Excellent balance of mechanical
properties because the degree
of crystallinity and the level of
orientation in the finished
product can be controlled.
Tough
Good barrier to gases
It is used in Beverage bottles,
film production.
It is used in plastic bottling
industry.
Recycling Plastics
Oil-based plastics don't degrade, but many types (including PP, LDPE, HDPE, PET, and PVC)
can be recycled. Each type has a code and identifying number, but some plastics aren't as
economically feasible to recycle. So it's important to check with recycler or municipality about
which types of plastics will be accepted.
Once collected, plastics go through the following steps
Inspection to weed out contaminants and inappropriate types of plastic
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Shredding and washing
Separation based on density
Drying
Melting
Draining through fine screens to remove more contaminants
Cooling and shredding into pellets
Selling back to plastic companies
Although plastics do pose disposal problems, recycling is always a possibility.
The most commonly used types of plastics are PO, PP, PS, PVC, PET, PC, PET, PU,
polyacrylates, polyvinyl acetates, and polyamides. These synthetic polymers are typically made
from the naphtha fraction of petroleum or natural gas; and are heavy pollutants as they are not
biodegradable.
Burning plastic wastes has not been an option either, as toxic gases such as hydrogen cyanide
and hydrogen chloride are emitted. Attempts to accelerate biodegradation via additives such as
chemicals, oxygen, and UV additives have not resulted in meaningful measurable reduction.
Degradability
Depending upon their properties polymers can be referred to as –
1. Biodegradable
2. Compostable
3. Hydro-biodegradable
4. Photo-biodegradable
5. Bioerodable
1. Biodegradable plastics are degradable plastic in which the degradation results from
action of naturally-occurring (i.e. no human interference) microorganisms like bacteria,
fungi and algae (ASTM D6400-99)
Biodegradability does not necessarily mean compostability. Biodegradability is one of
the components of compostability. Compostability in addition, requires disintegration of
90% of the material to a size less than 2mm, and also mandates that the compostable
material does not create any eco-toxicity in the soil.
By composting biodegradable plastic along with the other biodegradable waste, we can
generate much-needed carbon-rich soil (humus) instead of filling up our valuable land
with waste. Compost amended soil can have beneficial effects by increasing water &
nutrient retention in soil, reducing chemical inputs, (toxins, pesticides, etc.) and
suppressing plant diseases.
Biodegradable Plastics (BDP)
With the biodegradability characteristic BDP is useful mainly in post use stage in waste
management utilizing the composter. In agricultural and horticultural use or the civil
engineering and construction use BDP products has its advantage not to need to collect
the waste products.
2. Compostable plastic is plastic which undergoes degradation by biological processes
during composting to yield carbon dioxide, water, inorganic compounds, and biomass at
rate consistent with other compostable material and leaves no visible, distinguishable or
toxic residue. (ASTM D6400-99). Compostable biodegradable plastics must be
demonstrated to biodegrade and disintegrate in a compost system during the
composting process (typically around 12 weeks at temperatures over 50°C). The
compost must meet quality criteria such as heavy metal content, ecotoxicity, and no
obvious distinguishable residues caused by the breakdown of the polymers.
Compostable plastics are a subset of biodegradable plastics. Compostable plastic is a
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plastic that undergoes biological degradation at a rate consistent with other known
compostable materials, such as cellulose, leaving no visually distinguishable or toxic
residues.
Certified compostable bioplastics by ASTM are required to degrade within 180 days in a
commercial composting facility. Home composting systems may take more than 180
days to biodegrade. Based on the thickness, kind of resins, the bioplastics can have
varying rates of decomposition. The corn cutlery, cold cups, drinking straws and the
biobags can take up to 180 days in a commercial composting facility. The potato cutlery
will also take 180 days or more to degrade in a commercial facility. Biodegradation will
be faster if the products are broken down to small pieces or ground up. For all
bioplastics apart from the biobags, a commercial compost facility is recommended.
Composting programmes are required to effectively and economically dispose PLA
based commodities. NatureWorks (Cargill) company has started buy-back policy for PLA
containers and to appropriately dispose off them. This may attract customers.
3. Hydro-biodegradable and
4. photo-biodegradabe polymers are broken down in a two-step process - an initial
hydrolysis or photo-degradation stage, followed by further biodegradation. Single
degradation phase 'water-soluble' and 'photodegradable' polymers also exist.
5. Bioerodable – Many polymers that are claimed to be 'biodegradable' are in fact
'bioerodable' and degrade without the action of micro-organisms - at least initially. This is
also known as abiotic disintegration, and may include processes such as dissolution in
water, 'oxidative embrittlement' (heat ageing) or 'photolytic embrittlement' (UV ageing).
10. 10
Chapter 2
The Problem of Plastic
Effects of Plastic Pollution
The manufacture of plastics currently accounts for about 8 percent of the world's petroleum use,
a sizeable chunk, which ultimately contributes to another global concern-the accumulation of
carbon dioxide in the atmosphere. Plastic causes damage to the environment during production
and even after disposal. So the only way to reduce plastic pollution is to reduce its production.
Once produced plastic remains and causes hazard in one or other form. Dumping , recycling
only results in impacts at different place.
It is often said that problem is not with the plastic (since it is inert) but is with the disposal of
plastic (because it is inert). Plastic pollution will have negative impact on Environment,
ecosystem and finally on Human being.
50% by weight in plastic items are additives which are harmful. These additives can leach out in
environment.
Salient Features of Plastic Pollution
1. Excessive Molecular Size
2. Not Biodegradable
3. Long-ever Persistence
4. Aesthetic Nuisance
5. Drain on Limited Natural Resources
6. Found in guts of grazing animals and marine fish
7. Unsightly Heaps
8. Chocked Drains
9. Soil Erosion (As Grass does not grow) – Hillsides of HP
10. Recycling and Reuse low
11. Non-renewable (geological timeframes to produce but 1 to 10 years to consume)
12. Demand and production skyrocketing
When plastic is burned toxic chemicals like dioxin are released in air. Recycling of plastic is
uneconomical and labour-intensive. Recycling of plastics is associated with skin and respiratory
problems resulting from exposure to and inhalation of toxic fumes, especially hydrocarbons and
residues released during the process.
Plastic wastes clog the drainage system in urban localities and undue flooding. Plastic waste is
often dumped into rivers, streams and sea and it contaminates the respective ecosystem at all
the levels. Choked drainage system provides excellent breeding ground for mosquitoes.
Landfilling plastic means preserving plastic since plastic does not undergo microbial
degradation. Chemicals from landfills can cause seepage and groundwater contamination.
Every year 500 billion (500,000,000,000) plastic bags are used worldwide. Plastic bags are
difficult and costly to recycle and most end up on landfill sites where they take around 300 years
to photodegrade. They break down into tiny toxic particles that contaminate the soil and
waterways and enter the food chain when animals accidentally ingest them.
90% floating litter in marine environment is plastic. In the US in 2005, floating and submerged
objects caused 269 boating accidents (US Coast Guard), Resulted in 15 deaths, 116 injuries
and $3 million in property damages.
Food and beverage packaging is most common source of debris on streets and so part of
municipal garbage.
Two broad classes of plastic-related chemicals are of critical concern for human health-
bisphenol-A or BPA, and additives used in the synthesis of plastics, which are known as
11. 11
phthalates. BPA is a basic building block of polycarbonate plastics, such as those used for
bottled water, food packaging and other items. While it has been considered benign in the form
of a heavily cross-linked polymer, its bonds can break down over time, when plastics are
repeatedly washed, exposed to heat or other stresses, liberating the building blocks of the
chemical, which are toxic. BPA has been recognized since the 1940s as an endocrine disrupting
chemical that interferes with normal hormonal function.
Health risks associated with BPA is the fact that other ingredients-such as plasticizers-are
commonly added to plastics. Many of these potentially toxic components also can leach out
over time. Among the most common is a chemical known as di-ethylhexyl phthalate or DEHP. In
some products, notably medical devices including IV bags or tubing, additives like DEHP can
make up 40 or 50 percent of the product. "If you're in a hospital, hooked up to an IV drip "the
chemical that oozes out goes directly into your bloodstream, with no opportunity for
detoxification in the gut. This can lead to unhealthy exposure levels, particularly in susceptible
populations such as newborns." FDA has freshly expressed doubts about the safety of BPA with
respect to brain behavior and prostate gland of fetuses, infants and children.
Most of these studies are difficult due to lack of proper controls for comparison.
Effects on Land
Chlorinated plastic can release harmful chemicals into the surrounding soil, which can then
seep into groundwater or other surrounding water sources. This can cause serious harm to the
species that drink this water.
Landfill areas are constantly piled high with many different types of plastics. In these landfills,
there are many microorganisms which speed up the biodegradation of plastics.
Regarding biodegradable plastics, as they are broken down, methane is released, which a very
powerful greenhouse gas that can contribute significantly to global warming.
It takes 500-1000 years for plastics to degrade.
Plastic pollution has the potential to poison animals, which can then adversely affect human
food supplies. Grazing animals like cows often engulf plastic which accumulates in their
digestive system.
Effect on Ocean
Nurdles are plastic pellets (a type of microplastic) that are shipped in this form, often in cargo
ships, to be used for the creation of plastic products. A significant amount of nurdles are spilled
into oceans, and it has been estimated that globally, around 10% of beach litter is
nurdles. Plastics in oceans typically degrade within a year, but not entirely, and in the process
toxic chemicals such as bisphenol A and polystyrene can leach into waters from some plastics.
Polystyrene pieces and nurdles are the most common types of plastic pollution in oceans, and
combined with plastic bags and food containers make up the majority of oceanic debris. In 2012,
it was estimated that there was approximately 165 million tons of plastic pollution in the world's
oceans.
Effects on Marine Animals
Plastic pollution has been described as being highly detrimental to large marine mammals,
posing the "single greatest threat" to them. Some marine species, such as sea turtles, have
been found to contain large proportions of plastics in their stomach. When this occurs, the
animal typically starves, because the plastic blocks the animal's digestive tract. Marine
mammals sometimes become entangled in plastic products such as nets, which can harm or kill
them.
Over 260 species, including invertebrates, have been reported to have either ingested plastic or
become entangled in the plastic. When a species gets entangled, its movement is seriously
reduced, therefore making it very difficult to find food. Being entangled usually results in death
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or severe lacerations and ulcers. It has been estimated that over 400,000 marine mammals
perish annually due to plastic pollution in oceans. In 2004, it was estimated that seagulls in
the North Sea had an average of thirty pieces of plastic in their stomachs.
Seabirds that feed on the ocean surface are especially prone to ingesting plastic debris that
floats. Adults feed these items to their chicks resulting in detrimental effects on chick growth and
survival.
One million sea birds and 100,000 marine mammals are killed annually from plastic in our
oceans.
Effect on Human Being
Plastics contain many different types of chemicals, depending on the type of plastic. The
addition of chemicals is the main reason why these plastics have become so multipurpose,
however this has problems associated with it. Some of the chemicals used in plastic production
have the potential to be absorbed by human beings through skin absorption. Much is unknown
about how severely humans are physically affected by these chemicals. Some of the chemicals
used in plastic production can cause dermatitis upon contact with human skin. In many plastics,
these toxic chemicals are only used in trace amounts, but significant testing is often required to
ensure that the toxic elements are contained within the plastic by inert material or polymer.
The major chemicals that go into making of plastic are highly toxic and pose serious threat to
living beings of all species on earth. Constituents like benzene and vinyl chloride are proved to
cause cancer.
Synthetic noxious chemicals emitted during the production of plastic are synthetic chemicals like
ethylene oxide, benzene, xylene. These chemicals can cause birth defects, cancer, damage to
nervous system and immune system and also adversely affect blood and kidneys. Many of
these toxic substances are also emitted during recycling of plastic.
Problems with Existing Plastics
Polymer Common Applications Health Issues /Aesthetic Nuisance
Polycarbonate
(PC)
baby bottles, sports water
bottles
can leach out bisphenol A, a hormone
disruptor
Polystyrene
(PS)
foam insulation, packaging
peanuts, plastic utensils,
meat trays, egg cartons, take-
out containers, single-use
disposable cups
Uses benzene, styrene and 1,3-butadiene.
Styrene is a neurotoxin and is known to be
toxic to the reproductive system. PS releases
toxic chemicals when burned.
Polyvinyl
Chloride
(PVC or vinyl)
building pipes, siding,
membrane roofing, flooring,
and window frame; shower
curtains, beach balls, credit
cards, cooking oil bottles
Made from the vinyl chloride monomer; high
chlorine and additive content. Toxic additives
such as phthalate softeners leach out. PVC
releases dioxin and other persistent organic
pollutants.
Polyethylene
(PE)
Polyethylene films are used to
make agricultural mulch films,
garbage bags, paper
coatings, laminating materials
and other products.
Because they don't degrade in the
environment, they can cause severe pollution
problems. Bags litter beaches and streets.
Plastics can harm wildlife, especially aquatic
animals. Mulch films can block underground
water circulation and hurt soil quality.
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Question is –
1) Do we want Plastics?
2) Do we want all plastic material that is biodegradable or of ‗limited life‘?
3) Can we reduce generation of plastic wastes?
4) Can we improve management of plastic wastes?
5) Should we find ecofriendly alternatives?
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Chapter 3
Alternatives for Plastics
Biodegradable Plastics’ Promises
1. Market Demand
2. Material Variety
3. Use of Renewable Resources
4. Sustainable Development
5. Solution to Solid Waste management
6. Biodegradable, Compostable
7. Range of Applications
Shortcomings of Bioplastics
1. Poor interactions with fibers
2. Narrow processing window
3. Lack of reactive group
4. Thermal degradation
5. Brittleness
6. lack certain desirable properties , e.g. malleability and pliability
Challenges of Biodegradable Plastics
1. Cost of Production – High
2. Scale of Production – Small
3. Limitations in Properties
4. Processing Limitations
5. Technology only Two Decades Old
6. Public Awareness Insufficient
7. Standardization still in process
8. Competition with Most Versatile and Most Popular Material Option
9. Not Totally Free from Fossil Fuel Use
10. More Energy Required for Production *
11. More Green-House Gases on Disposal
* 1 Kg PE – 2.2 Kg Fossil Fuel Required
* 1 Kg PHA – 2.6 Kg Fossil Fuel Required
Issues Discussed in favor and against Bioplastics
1. Environmental Costs must be attached to non-degradable plastics
2. Exemption from taxes for biodegradable plastics
3. Fair competition
4. Life-cycle analysis – From cradle to graveyard
5. Energy balance – Carbon balance
6. Only convenience not agreed
Approaches for production of biodegradable plastics
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1. Direct use of renewable plant material (starch, cellulose, fiber, lignin etc)
2. Microbial fermentations of renewable plant material (like starch, cellulose, oil) to produce
materials ((PHA) polyhydroxyalkonates or lactic acid (Monomer for polylactic acid) for
plastic
3. Genetically engineered microorganisms to produce more ((PHA) polyhydroxyalkonates
or lactic acid for bioplastic
4. Genetic engineering of plants (Alfalfa, oilseed rape, corn, sugarcane, potato, canola,
soybean, tobacco etc) to directly produce biodegradable plastics such as
polyhydroxyalkonates (PHA),
5. Fermentation of wastes (Oil mill effluents, whey, excess sludge), to produce ((PHA)
polyhydroxyalkonates or lactic acid (Monomer for polylactic acid) for biodegradable
plastics
6. Blends
Biodegradable Polymers for Bioplastics
(I) Natural Polymers
i. Starch-based Polymers – Plant based
ii. Polylactides (PLA) – Lactic acid by fermentation
iii. Polyhydroxyalkonates (Polyhydroxybutyrate) (PHB) – Microbial source
iv. Cellulose: Cellulose esters, cellulose ethers, cellophane (cellulose pulp from
trees or cotton may be used to produce cellophane), cellulose diacetate
v. A protein in corn gluten meal ‗zein‘
vi. Lignin based biopolymers
vii. Soyabean protein and oil
viii. Protein-based polymers that come from bacteria
ix. Proteins – Mainly from animal source – Collagen, casein, albumin, silk, feather, keratin
x. Agricultural lignocellulosic fiber polymers, Agricultural lignocellulosic residues –
Cotton, Jute, Sisal, Flax, Hibiscus, Pinapple leaves, Banana, Date Palm, Coir, Rice,
Wheat, Cereal, Sugarcane bagasse
xi. Naturally occurring polymerizable monomers, Agricultural monomers – sugars,
castor oil, other vegetable oils, cashew nut shell liquid, natural rubber, shellac,
terpenes
xii. Sugarcane plants
(II) Synthetic Polymers
Aliphatic polyesters, Poly (ether-esters), Poly (amide-esters), Poly (vinyl-esters),
Poly (ester-urathanes), Poly (aspartic acid), Poly (phosphazenes), Poly (vinyl alcohol),
Poly (e) caprolactone (PCL), Polybutylene adipate
i. Polycaprolactone
ii. Polyethylene compounded with starch or modified starch
iii. Polyethylene compounded with photooxidative additives
Blends of Natural and Synthetic materials
i. Wheat starch with synthetic polymers
ii. Ground barley grain with recycled plastic
Polymer containing starch and PCL (polycaprolactone)
Blends of Natural materials
i. Wheat starch with polylactic acid
ii. Starch-protein complexes
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iii. Fibers, proteins, starch, lipids from corn – (Vegemat)
Biomass-based Plastics
Anything that can be made from hydrocarbon can be made from carbohydrate. Plant based
plastics can be completely biodegradable. A carbohydrate-based economy is considered as the
answer to our environmental and economic woes.
There are varieties of renewable materials of plant origin which have been tried for preparation
of biodegradable plastic material.
1. Hemp as source of biodegradable plastic:
2. Biodegradable Plastics from Elephant Grass (Miscanthus):
3. Wheat as source for plastics:
4. Soya-based Biodegradable Plastics:
5. Corn as Source of Biodegradable Plastics:
6. Lignin-based Biodegradable Plastics:
7. Casssava Starch as Source for Biodegradable Plastics:
8. Biodegradable Plastics from Maize:
9. Potato starch for Biodegradable Plastics:
10. Biodegradable food containers from reed & sugarcane waste:
11. Natural Fibers as source of biodegradable plastics:
12. Cellulose-based Plastics: Celluloid and Rayon:
13. Biodegradable Plastics (PHA) from palm oil:
14. Biodegradable plastics from feathers:
Economics of Bioplastics
The Cost Factor
Biodegradable plastic products currently on the market are from 2 to 10 times more expensive
than traditional plastics. Polylactic acid, Polyhydroxy alkonates are more costly to produce.
In Australia, the Cooperative Research Centre (CRC) for International Food Manufacture and
Packaging Science is looking at ways of using basic starch, which is cheap to produce, in a
variety of blends with other more expensive biodegradable polymers to produce a variety of
flexible and rigid plastics. These are being made into 'film' and 'injection moulded' products such
as plastic wrapping, shopping bags, bread bags, mulch films and plant pots.
Price of PLA was $1.3 per lb when NatureWorks had 300 million pounds production per year.
Though that strained NatureWorks‘ capacity, PLA today sells for about 85¢/lb. The next stage of
cost reduction for PLA (and also PHA) could someday be to use less expensive biomass as a
feedstock. One potential source is corn stover, using the entire corn plant including stalks and
cobs, not just kernels. SRI Consulting in Menlo Park, Calif., estimates that operating a PLA plant
on corn stover could yield lactic acid (PLA‘s precursor) for 35¢/lb.
While the conventional commonly used polymers cost around US$1000-1500/MT, biopolymers
cost from about US$4000/MT to as high as US$15,000/MT for material such as
polyhydroxybutyrates. However, more commonly used biopolymer like polylactic based polymer
cost at least US$4000/MT. As the initial phase of development gets over and manufacturing
plants attain higher productivity, prices are projected to decline significantly. However, it will
never really reach the level of commonly used petroleum based polymers. Currently, from an
overall price comparison standpoint, biopolymers are 2.5-7.5 times more expensive than
traditional major petroleum based plastics. Yet, only five years ago, biopolymers were 35-100
times more expensive than existing non-renewable, fossil fuel based equivalents.
Price factor for PHA as Bioplastic:
Commercial applications and wide use of PHAs is hampered due to its price.
Today price with natural producer like A. eutrophus is US $16 per kg.
17. 17
Zeneca Bio Products (Bellingham, UK) produced approximately 1000 tonnes per year of
PHB/V at ca. US $16/kg. This is about 18 time more expensive than polypropylene.
Other biodegradable polymers such as polylactides, diol-diacid based aliphatic
polyesters, and starch-based polymers are currently sold at US $5-$12 per kg.
For PHA to be commercially viable price should come to US $3-5 per kg. With
recombinant E.coli as producer of PHA, price can be reduced to US $4 per kg., which is
close to other biodegradable plastic materials such as polylactides and aliphatic
polyesters.
With transgenic plants producing PHA price comes to only US 20 cents per kg.
Most important aspect is its biodegradable nature helps to overcome the problem of
environmental hazard. And the value of clean environment will otherwise also outweigh
conventional plastics on price factor in favour of more and more use of PHA.
Apart from environmental advantages (better waste management), Biopol is made from
renewable sources- sugars refined from crops rather than fossil fuels. Biopol need not be
thrown away and can be recycled or burned cleanly to provide energy in an incinerator.
Recently, Metabolix Inc. has successfully scaled up production of its PHA bioplastics at a cost
per pound that could make them competitive with traditional petrochemical resins for
applications in polymer markets, specifically in the packaging area. With the company's
patented recovery technology, production of PHAs may come in at costs below $1.00 per pound
at full commercial scale.
In May, 2003, the U.S. Department of Commerce's Advanced Technology Program (ATP)
awarded Metabolix $1.6 million, allowing scientists to develop even more efficient conversion
methods of renewable sugars into PHA plastics. ATP award will help Metabolix achieve
dramatic improvements in the efficiency of microbial fermentations, leading to lower costs for
PHAs.
Price factor for PLA as Bioplastic:
For markets of about 900,000 metric Tons/year, PLA‘ selling price will favourably compare with
oil-based plastic materials used by the packaging industry.
Problem with biodegradable plastics
1. Cost is the single most important factor that drives commercialization forward.
2. Apart from cost factor, the other main drawback that the industry is facing with
bioplastics, is the low water-barrier and
3. The migration of hydrophilic plasticizers with consequent ageing phenomena.
Disposal Cost and Environmental Issues
Environmentalists argue that the cheaper price of traditional plastics does not reflect their true
cost when their full impact is considered. For example, when we buy a plastic bag we don't pay
for its collection and waste disposal after we use it. If we added up these sorts of associated
costs, traditional plastics would cost more and biodegradable plastics might be more
competitive.
Disposal cost and environmental cost should be added to cost of processing when comparison
is done of usual plastics with biodegradable plastics.
T. Gerngross et al. in 1999 and in 2000 in their articles indicated that the energy required to
produce one kilo of polyhydroxyalkanoate (PHA) biopolymer (by fermentation) from plants was
equivalent to the consumption of 2.65 kg of fossil fuel while the production of one kilo of
polypropylene required only 1.54 kg of fossil fuel. These balances include the energy required to
produce the feedstock as well as the polymer.
Life cycle assessment data for the production of polyhydroxyalkanoates from sugar cane
(Brazil) was not mentioned in these studies. Manufacturing of PHAs by fermentation in Brazil
18. 18
enjoys a favorable energy consumption scheme where bagasse is used as source of renewable
energy.
Technology to produce PHA is still in development, and energy consumption can be further
reduced by eliminating the fermentation step, or by utilizing food waste as feedstock.
Starch-based biopolymers (produced by various manufacturers) and polylactide (produced by
NatureWorks in the US) require less fossil fuel than polymers from non-renewable sources, but
have the disadvantage of competing against food production.
Italian bioplastic manufacturer Novamont states in its own environmental audit that producing
one kilogram of its starch-based product uses 500g of petroleum and consumes almost 80% of
the energy required to produce a traditional polyethylene polymer. Environmental data from
NatureWorks, the only commercial manufacturer of PLA (polylactic acid) bioplastic, says that
making its plastic material delivers a fossil fuel saving of between 25 and 68 per cent compared
with polyethylene, in part due to its purchasing of [renewable energy] certificates for its
manufacturing plant.
According to Athena Institute (US) the bioplastic are less environmentally damaging for some
products, but more environmentally damaging for others. The authors' key finding is that the use
of bioplastics cannot be assumed to be environmentally beneficial, but has to be determined
through case by case analysis.
While production of most bioplastics results in reduced carbon dioxide emissions compared to
traditional alternatives, there are some real concerns that the creation of a global bioeconomy
could contribute to an accelerated rate of deforestation if not managed effectively. There are
associated concerns over the impact on water supply and soil erosion.
Energy Requirements for Production
Megajoules per
kilogram of plastic
Megajoules per kg
on Raw Material
1 PHA (Grown in Corn plants in stover) 90
2 PHA (Bacterial Fermentation) 81
3 PLA 56
4 PE (Fossil Fuel Based) 29 81
5 PET(Fossil Fuel Based) 37 76
Biopolymer Production Capacities
Biopolymer producers don‘t divulge their production volumes, but the stated plant capacities for
the two most widely used biomaterials—starch-based Mater-Bi from Novamont in Italy and
polylactic acid (PLA) from NatureWorks far exceed those numbers. Nameplate capacity for PLA
is 300 million lb/yr, while Novamont‘s combined in-house and outside-contracted Mater-Bi
compounding capacity totals 77 million lb/yr.
Novamont is building a 125-million lb/year compounding plant in Italy, and NatureWorks is also
increasing its output from 2008.
Disposal of Bioplastics
Biodegradable plastic bags for compost collection are a successful application because of labor
savings. The bags don‘t have to be opened, but go directly into the compost.
Biodegradable rigid trays and bottles, however, require a collection and industrial composting
infrastructure.
19. 19
Countries, like Holland, have extensive industrial composting infrastructure. Some, like England,
have no industrial composting but lots of the backyard kind. So PLA, which needs industrial
composting to break down, ―has no desirable disposal route‖ in the U.K.
Petro-based additives for bioresins are another issue. For example, DuPont‘s new Biomax
Strong ethylene acrylate modifier is designed to be used at 1% to 20% levels in PLA
applications to fix PLA‘s problem of brittle cracking. Biomax also improves the quality of trimmed
edges for thermoformed parts. But European Union rules allow no more than 10% of a non-
biodegradable ingredient or else the whole composition is classed as non-biodegradable.
There is also concern in Europe over biopolymers based on genetically modified (GM) U. S.
Corn. NatureWorks offers to supply ―Non-GM‖ PLA for a premium price.
Issues with Bioplastics
Since PLA plastics produce methane gas when they decompose composting is not right method
for their disposal. On the other hand, if incinerated, bioplastics don't emit toxic fumes like their
oil-based counterparts. If commercial composting isn't available, PLA plastics can wind up
following conventional plastics into the landfill or into plastic recycling programs. Corn plastic
(PLA) only composts in the hot, moist settings of a commercial composting facility. PLA plastics
if contaminate normal plastics then it prevents salvaged plastic from being reused and stopping
recycling companies from profiting from one of their more lucrative recyclables. As with corn
ethanol, corn plastic has also drawn criticism for depending on the industrial farming of large
fields of crops. These fields could otherwise be used to grow food for an ever-rising global
population. Much of the corn used for bioplastics is a variety called Number 2 Yellow Dent that's
used mostly for animal feed.
In Europe the composting standard is EN 13432 while in USA it is ASTM D6400
Challenges for Bioplastics
Will bioplastic bottles contaminate PET recycling programs? NatureWorks' PLA is already being
made into a beverage container for Biota Spring Water. Should the bottles be labeled as
compostable or recyclable? NatureWorks advertises its PLA as both recyclable and
compostable and reports that independent technical studies indicate PLA is not a recycling
contaminate. When mixed with PET, for instance, PLA only exhibited hazing and color affects
on the PET at concentrations above 0.1% (1,000 ppm). PLA is not yet a contaminant because it
has so little market share at this time.
When bioplastics are fully rolled out, how will they ultimately affect recycling of conventional
plastics? How will consumers know to recycle or compost products? Currently bioplastics carry
the chasing arrow symbol but this has limited value in educating consumers. The Society of the
Plastics Industry resin code identification protocols stipulate that manufacturers have to "make
the code inconspicuous at the point of purchase so it does not influence the consumer's buying
decision." These questions need to be addressed before the recycling community will embrace
bioplastics, particularly beverage containers.
20. 20
Chapter 4
Worldwide Scenario of Bioplastics Market and Activity
Market for Plastics in World
The plastic industry in the US alone is $ 50 billion per year. Over 200 million tonnes of plastic
are manufactured annually around the world, according to the SPE. Of those 200 million tons,
26 million are manufactured in the United States. The EPA reported in 2003 that only 5.8% of
those 26 million tons of plastic waste are recycled, although this is increasing rapidly.
Biopolymer Production Capacity (2015)
No. Type of Bioplastic Polymer Metric Tonnes % Share
1 Bio-PE (Not Compostable) 4,50,000 26
2 Bio-PET (Not Compostable) 2,90.000 17
3 PLA (Compostable) 2,16,000 13
4 PHA 1,47,100 09
5 Biodegradable Polyesters 1,43,500 08
6 Biodegradable Starch Blends 1,24,800 07
7 Bio-PVC 1,20,000 07
8 Bio-PA 75,000 05
9 Regenerated Cellulose 36,000 02
10 PLA Blends 35,000 02
11 Bio-PP 30,000 02
12 Bio-PC 20,000 01
13 Others 22,300 01
Total 1,709,700 100%
Source: Eurpean Bioplastics European Bioplastics/University of Applied Sciences and Arts
Hanover, May 2011
Market for Bioplastics
According to market research firm IBISWorld, the global plastics manufacturing market is worth
$779.8 billion in 2012 and is expected to grow to $941.4 billion in 2017. Approximately 28.7
percent of industry revenue is accounted for in North America, 28.5 percent in Europe and 25.5
percent in Asia. Asia‘s share has been growing because of development in China, resulting in
declining share for North America and Europe.
In comparison to the $779.8 billion plastics market, bioplastics make up just a sliver: only $2.3
billion in 2011, according to Transparency Market Research. The bioplastics market is growing
faster than the overall market, though. The firm expects bioplastics to reach $7.8 billion in 2018,
an annual growth rate of 19.5 percent.
The use of non-toxic bioplastics is increasing in the medical, packaging, food, toys, textile and
horticulture industries. There are also plans to use them in the electronic and automotive
industries. The value of the global bioplastics market is expected to reach about MYR30.3bn
($10bn) by 2020 as a result of consumer preferences and environmental concerns. It currently
accounts for about 15% of the total plastic demand and this is expected to rise to 30% by 2020.
From 2006 to 2011, bioplastics have experienced explosive growth of 1,500% to a current
aggregate capacity of 470,000 tons, and a 10.9% share of all bio-based materials. Expansion is
expected to moderate, though their capacity will still grow 57% from 2011 to 2016.
Cellulose polymers and starch-based plastics are dominant. Cellulose polymers and starch-
derived materials still rule because they are durable, strong and easily biodegradable: They‘ve
21. 21
been widely used in high-performance plastic coatings, buttons and yarns. However, their share
of total capacity will slide from 45% in 2011 to 21% in 2016.
According to Jeff Bishop, an analyst at San Francisco's Beacon Equity Research, 20% of the
world‘s plastic production could be captured by bio-based plastics in 2020 (Schneyer, 2008).
Braskem on the other hand expects bio-based plastics to take over 10% of the worldwide plastic
market by the year 2020.
Proprietary PLA biopolymer is marketed under Ingeo trademark. It is competitive on cost and
performance basis to traditional plastics. It has superior environmental characteristics. It has
established global market channels. It has 20 applications in more than 70,000 store shelves
globally. By volume it is 100 million pounds. Main customers include Wal-Mart, Frito-Lay, and
Coca-Cola.
Factors affecting Biopolymer Market
1. Soaring oil prices,
2. Depleting oil reserves,
3. Worldwide interest in renewable resources,
4. Growing concern regarding greenhouse gas emissions and
5. A new emphasis on waste management
6. Total Life Cycle Assessment,
7. Legislative incentives (particularly in European Union),
8. Suitability of material properties,
9. Technical feasibility of processing options, and
10. Commercial viability of production and processing.
11. Consumer Acceptance
12. Range of Applications
The use of legislative instruments is a significant driver influencing the adoption of biopolymers
in place of the petroleum based polymers. In Europe and Japan, the automotive and packaging
sectors are most affected by ratified legislation. The Packaging and Packaging Waste Directive
94/62/EC and the End of Life Vehicle Directive 2000/53/EC are two examples of such legislative
drivers. Additionally, in the U.S. Section 9002 of the Farm Security and Rural Investment Act of
2002 confers federal purchasing preference to biopolymer based products.
Market for Bioplastics
Bioplastics receive an increasing amount of attention by both industry and consumers as one of
the main drivers toward a bio-economy. The term bioplastics, however, encompasses a range
of polymers that can either be bio-based (at least partially), biodegradable or both. As of today,
these materials account for approximately 1.5% of global plastics demand, but it is estimated
that they could substitute up to 85% of conventional polymers.
Plastics market have grown from just 1.5 million tonnes in 1950 to over 250 million tones in
2010. According to Frredonia Group Incorporation Report, Global demand for bioplastics, plastic
resins that are biodegradable or derived from plant-based sources, will rise more than fourfold
to 900,000 metric tons in 2013, valued at $2.6 billion. Growth will be fueled by a number of
factors, including consumer demand for more environmentally-sustainable products, the
development of bio-based feedstocks for commodity plastic resins, and increasing restrictions
on the use of nondegradable plastic products, particularly plastic bags. Rising prices of crude oil
and natural gas will make bioplastics more cost-effective.
Asia will play a critical role in any large-scale commercialization scenario of bioplastics, its
regional differences are striking when considering parameters such as feedstock availability,
industry infrastructure, customer industries and government policies. They become important
drivers in commercialization of bioplastics in some of the region's key countries - notably Japan,
Thailand and China
22. 22
A recent study by Nova Institute forecasts global biopolymer capacities to grow from 3,500 kt in
2011 to approximately 12,000 kt in 2020. New production capacity in Asia alone will be larger
than combined additions in the rest of the world.
Bioplastics will grow at a significant pace over the next 5 years. The total worldwide use of
bioplastics is valued at 571,712 metric tons in 2010. This usage is expected to grow at a 41.4%
compound annual growth rate (CAGR) from 2010 through 2015, to reach 3,230,660 metric tons
in 2015.
According to BCC Research Report, by 2010, ready access to crops such as soybeans, corn,
and sugarcane moved the United States strongly into bioplastics. North American usage is
estimated at 258,180 metric tons in 2010 and is expected to increase at a 41.4% compound
annual growth rate (CAGR) to reach 1,459,040 metric tons in 2015.
Use of bioplastics got off to a faster start in Europe than in the United States. European usage is
now reported at 175,320 metric tons in 2010 and is expected to increase at a 33.9% compound
annual growth rate (CAGR) to reach 753,760 metric tons in 2015.
Globally, bioplastics make up nearly 331,000 tons (300,000 metric tons) of the plastics market
[source: European Bioplastics]. Thus bioplastics account for less than 1 percent of the 200
million tons (181 million metric tons) of synthetic plastics the world produces each year
[source: Green Council]. Still, the bioplastics market is growing by 20 to 30 percent each year.
Non-biodegradable plant-based plastics will be the primary driver of bioplastics demand, rising
from just 23,000 metric tons in 2008 to nearly 600,000 metric tons in 2013.
By 2015, growth is expected for PLA and PHA, each accounting for 298,000 tonnes and
142,000 tonnes respectively.
In the market forecast report - published by European Bioplastics annually in cooperation with
the Institute of Bioplastics and Biocomposites from the University of Hannover – the industry
association says that the market of around 1.2 million tonnes in 2011 will see a fivefold increase
in production volumes by 2016 to approximately 5.8 million tonnes.
Biodegradable plastics, such as starch-based resins, polylactic acid (PLA) and degradable
polyesters, accounted for the vast majority (nearly 90 percent) of bioplastics demand in 2008.
Western Europe was the largest regional market for bioplastics in 2008, accounting for about 40
percent of world demand. Bioplastics sales in the region benefit from strong consumer demand
for biodegradable and plant-based products, a regulatory environment that favors bioplastics
over petroleum resins, and an extensive infrastructure for composting. Demand will grow more
rapidly in the Asia/Pacific region, which will surpass the West European market by 2013.
There will be strong demand in Japan, and other regions, such as Latin America and Eastern
Europe. Currently, world bioplastics production is heavily concentrated in the developed
countries of North America, Western Europe and Japan. This will change dramatically by 2013
when Brazil will become the world‘s leading producer of bioplastics. Furthermore, China plans to
open over 100,000 metric tons of new bioplastics capacity by 2013, making that country a major
player in the global industry.
In 2008, while total world demand for bioplastics was 200,000 tons, share of Western Europe
was 38%, North America was 29%, Asia Pacific 29% and others 4%.
In comparison more than 30 million tons of oil-based plastics are produced in world.
New analysis from Frost & Sullivan, Global Bio-based Plastics Market, finds that the market
earned revenues of €570.6 million in 2008, and estimates this to reach €1.1 billion in 2015.
1. Improvements in product performance and
2. an expanding product range
are responsible for the bio-based plastics being found in new and high-growth applications. This
is despite the challenges posed by the economic downturn and resulting price sensitivity of
customers.
23. 23
The global bioplastics market has reached a critical juncture in its growth phase, with a large
number of companies now focusing on transitioning from laboratory and pilot scale to full-
fledged commercialization.
The move towards sustainability in key end user markets for plastics will continue to drive the
demand for sustainable bio-based plastics. The ever increasing product mix in bio-based
plastics will ensure that a wide range of applications is made available for bio-based plastics to
capitalise upon.
Plastics are expanding into newer areas that were traditionally catered to by engineering
plastics like polybutylene terephthalate (PBT) and acrylonitrile-butadiene-styrene (ABS). This
was made possible by significant improvements in the production methods and additives in bio-
based plastics, opening up new avenues of growth for bio-based plastics.
The development in bio-based commodity and technical plastics will pave the way for
bioplastics to expand into two different ends of the performance scale. While bio-based
commodity plastics will accelerate the growth of bioplastics in packaging and similar
applications, the growth in technical bio-based plastics will enable expansion into automotive,
electronic and consumer goods applications.
The main challenges facing the bio-based plastics market in the short term stem from the
impact of the economic slump, which will make funding of major project expansions complex.
However, in the long term, the challenges are more structural such as enhancing the recycling
infrastructure as well as technical properties for bioplastics.
Although, sufficient capacity is currently available for most of the bio-based plastic types, future
market growth will mainly depend on crucial capacity additions taking place according to
schedule.
Partnership with key market participants will be critical to long-term success in the rapidly
growing bio-based plastics market. For example, partnership with major chemical companies
will ensure that bio-based plastic producers with a predominantly agricultural background will
gain rapid access to critical technology and market development capabilities.
Bio-plastic suppliers should focus on improving product performance and the depth of their
product range if they are to succeed in the rapidly evolving markets for bio-based plastics. End
users need to be made aware of the various alternatives available in bio-based plastics, with a
clear definition of the performance and end-of-life characteristics of each of these bio-based
plastics.
According to the European Bioplastics association, 'Global bioplastics production capacity is set
to grow 500% by 2016'. According to this report, Europe's bio-economy sectors are already
'worth Euro 2 trillion in annual turnover and account for 22 million jobs in the EU'. Global
production capacity of bioplastics amounted to some 1.2 million tonnes in 2011 and will rise to
almost 6 million tonnes by 2016, it is envisaged. According to European Bioplastics, the
association representing the interests of Europe‘s thriving bio-plastics industry, bio-plastics
production capacity in the world is expected to reach 6.2 million tons in 2017, an immense
increase from 1.4 million tons in 2012.
Activities in Bioplastics in Asia
In 2011, Asia held 34.6% of the global bioplastics production capacity, followed by South
America‘s 32.8%, Europe 18.5%, and North America 13.7%. Australia held the remainder 0.4%.
Asia is expected to hold 46.3% of the world‘s bioplastic production capacity by 2016.
Bioplastics in Japan
Japan has high dependency on naphtha imports. Japan strives to strategically diversify its raw
material supply. Its traditionally strong chemical companies, innovative customer industries and
environmentally conscious consumers provide suitable ground for development and launch of
bio-based material alternatives.
24. 24
Automotive powerhouse Toyota is on the global forefront in committing to the use of bioplastics
in applications such as vent louvers or radiator end tanks.
Chemical industry players Mitsubishi Chemical, Mitsui or Teijin are all engaged in bio-based
material research projects. Japan, however, lacks the natural resources and agricultural space
to become a bioplastics production center on its own. Large-scale investments of Japanese
companies are therefore taking place in feedstock-rich regions of the world. Mitsui has entered
a joint venture for bio-PE production with Dow Chemical in Brazil, and Mitsubishi Chemical is
constructing a bio-PBS plant with its local partner PTT in Thailand.
Bioplastics in Thialand
Thailand is set to become one of the largest bioplastics producer globally, particularly after PTT
Chemicals Plc revealed in October 2012 a collaboration with Japan‘s Mitsubishi and US‘s
NatureWorks to develop a biorefinery.
Bioplastics manufacturing is regarded as one of Thailand‘s new wave businesses. The bio-
plastics industry has received a major boost. There are currently 31 bio-plastics manufacturers
in Thailand. Many of them have produced plastics bags for exports to the European Union and
the United States. The number of bio-plastics manufacturers in Thailand is still minimal, when
compared with 2,378 conventional plastics producers in the country. The Office of Industrial
Economics in Thailand will organize training in bio-plastics for 100 entrepreneurs to promote
bio-plastics manufacturing. This will help retain the country‘s status as the top bio-plastics
producer in this region.
In October 2011, PTT announced that it would acquire a 50% stake in NatureWorks for US$150
million, and work together to establish a second Ingeo plant in Thailand, tentatively scheduled
for 2015.
Mitsubishi Chemical is constructing a bio-PBS plant with its local partner PTT in Thailand. Other
investments in Thailand - e.g., the 75 kt PLA monomer plant of Purac is evidence of the
country's ambitions in becoming the major production hub for bioplastics in Asia. Two
competitive advantages stand out for Thialand are – (1) Thailand's big agricultural base as a
major global cassava and sugar exporter, and (2) supportive government policies addressing
strategies, standards and incentives in the National Roadmap for the Development of the
Bioplastics Industry.
Furthermore, Thailand boasts a strong upstream chemical value chain including numerous
starch, sugar and glucose plants as well as the largest plastics processing industry in Southeast
Asia.
Bioplastics in China
With the 12th Five-Year Plan (2011-2015), China‘s government has started including
environmental sustainability among its main political targets. Plastics recycling reduces the
amount of petrochemicals needed to make plastics, and at the same time reduces the amount
of waste that needs to be deposited or incinerated. China is a major global centre for plastics
recycling, importing more than eight million tons of waste plastics on top of the approximately 10
million tons recovered from domestic sources. Biodegradable plastics are made from traditional
petrochemicals or renewable sources but are modified in order to increase their degradability
under naturally-occurring conditions. Bioplastics are made from renewable biomass such as
starch and vegetable oil rather than from petrochemical sources. Bioplastics often are
biodegradable, but do not necessarily have to be.
China Green Material has an annual capacity of 32 kilotonnes of starch-based plastics, mainly
for film and packaging applications. Two Chinese companies, Ningbo Tianan Biomaterials and
Tianjin Green Bioscience, are already engaged in commercial production of PHA based
bioplastics with annual capacities of eight-10 kilotonnes. China‘s combined total annual PLA
production capacity is about 20 kilotonnes, but all the top five local producers have stated their
25. 25
intention to reach capacities of at least 10 kilotonnes, which should result in a rapid expansion
of the countrywide capacity. The leading company, Zhejiang Hisun Biomaterials, which was
formed in co-operation between the Changchun Institute of Applied Chemistry and Zhejiang
Hisun, produces five kilotonnes-per-year of PLA and claims to be the first commercial producer
of PLA resin. PLA is used in China for packaging, textile coatings, and medical and agricultural
applications. Currently, it is primarily driven by government support in the shape of a special
fund to aid the research and development of PLA technology. Polyamide 11 is a bioplastic made
from natural oil that has been commercialised by French chemicals giant Arkema. Its properties
are similar to those of other polyamides and it is not biodegradable, though it requires less non-
renewable resources for production.
In China, Suzhou HiPro is currently expanding its capacity from five kilotonnes to 15 kilotonnes
by 2012. The Polyamide 11 produced from Suzhou HiPro material is used in automotive and
consumer electronics applications. An investment from Bain Capital in the company is an
indication of its growth potential.
Overall, with some exceptions such as polyamide, the consumption of bioplastics and
biodegradable plastics in China is not very large yet. Most of the material produced locally is
exported as the materials are priced higher than petrochemical plastics, and China is more price
sensitive and has less of a preference for environmentally-friendly materials than Western
markets.
China is the largest plastics processer in the world. Since 2010 its annual plastics consumption
is larger than that of all European countries combined. It must therefore play a crucial role in any
large-scale commercialization scenario of bioplastics. Current bioplastic capacities in China are
yet remarkably small at approximately 300 kt and focus almost entirely on biodegradable
materials such as starch, PBS and PLA. Local market demand is at present almost negligible.
But interpreting the ongoing Chinese paradigm shift "from rapid development to more inclusive
growth," there are at least three major end-user effects driving the market potential for
bioplastics in the country:
Increasing purchasing power and rising environmental consumer awareness
More sophisticated, value-added products being manufactured in China
Proliferation and globalization of Chinese brands.
China-based Shanxi Jinhui Energy Group launched its venture into bioplastics production, with
a $35 million bio-based polybutylene adipate co-terephthalate factory. The factory has the
biggest production capacity of PBAT in Asia and produces biomaterial capable of decomposing
completely in a period of 180 days, breaking down into only carbon dioxide and water. The
company's PBAT materials have been approved by the U.S. Food and Drug Administration for
food-contact use.
Bioplastics in Korea
The Korean bio-industry is also growing, with the production valued at 7.12 trillion won (around
US$6.9 billion in 2012. Ministry of Trade, Industry and Energy has announced that around 215
billion won (over US$200 million) will be invested in the biochemicals industry. Despite this
investment Korean market for bioplastics is small.
Green Chemical Ltd.constructed its plant in 2006 and started producing 100% biodegradable
PLA. These PLA sheets are used in items like food containers and sold at chain supermarkets
and department stores. This company imports 100 tonnes of raw PLA material every month.
The market for PLA is only about 200 tonnes per month, still less than 1% of the total plastics
market in Korea. Market for PET is 20,000 tonnes per month.
Korea Biodegradable Plastics Association (Now, Korean Bioplastics Association) was
established in 1999. Korea has good record of R & D in Biomaterials.
26. 26
Bioplastics Market in India
News analysis from Frost & Sullivan on ―Bioplastics in India‖ finds that market grew at 30% in
2008 and will grow at compound annual growth rate (CAGR) of 44.8% between 2009 and 2015.
There is currently no legislation in India to support bioplastics. India has potential to produce
biopolymers because of availability of ample feedstock.
―According to various sources, the per capita annual consumption of plastic in the country stood
at 150 bags per person and is expected to go up to 200 nos by 2011.‖
― In addition to this the Plastic Development Council states that India is expected to be the third
largest consumer of plastics after US and China by 2011.
Bioplastics production in India
Bioplastics in India are still at a very nascent stage with only two participants operating in this
segment. As compared to the European market, where bioplastic products are commercially
available, the Indian bioplastics industry has a long way to go in terms of production, raw
materials, and technology. Although the Indian Bioplastics market is beset by challenges such
as low awareness that are typical to emerging markets, the inadequate market response
signifies huge potential for companies wishing to enter this market. Participants can overcome
the awareness barrier by creating greater environmental awareness and promoting the long-
term environmental benefits of using Bioplastics over petroleum-based plastics.
Central Institute of Plastics Engineering and technology, Chennai (CIPET) is carrying out
research on biodegradable plastics and has testing facilities to evaluate them.
(1) Earthsoul is India‘s exclusive manufacturer licensees for Novamont. Mater-Bi products.
Mater-Bi is manufactured in 20000 t/annum plant in Novara Italy. Starch is derived from
corn, wheat, potato starch. It is completely biodegradable in composting cycle.
Biodegradability and atoxicity of Earthsoul®
have been measured by Organic Waste
System (Belgium), VTT (Finland), Catholic University of Piacenza (Italy), Marxer Institute
of Biomedical Research (Ivrea, Italy), Weimar University (Germany) and Novamont
laboratories.
Jammu and Kashmir (J&K) will be the first state in India to have a fully dedicated
bioplastic product manufacturing facility with an installed capacity of about 960 metric
tonnes per year. The state-of-the-art facility commenced production by October 2009.
The J&K Agro Industries Ltd is going for a joint venture with EARTHSOUL for the
manufacture of 100 per cent bio-degradable and compostable products. This would be
India‘s first integrated biopolymer facility. The facility would be manufacturing flower pots
and trays for floriculture, carry bags for all shopping applications, outer packaging
material for foodstuff and meats, etc, bin liners for hotels and clubs. These products
have a huge market in the country and abroad. It is interesting to note that India
consumes around five million tonnes of plastic products per annum which is trebling
every decade. It is expected to touch 12.5 million tonnes by 2010, making India the third
largest consumer of plastics. In India, a law introduced in 2003 has banned 20 micron
plastic bags in Mumbai and Delhi. The states of Maharashtra, Kerala and J&K have
banned the use of plastic bags. Recently the use of polythene bags in Srinagar and
other parts of the Valley has been made a finable offense.
(2) BIOPLAST - Biodegradable Polybag – Enzyme based by Ravi Industries, Nagpur-
440016, Maharashtra, INDIA, Mobile +00-91- 9962009933 Mobile +00-91- 93709 86202
(3) SPC Biotech, Plot No. 8, Lalith Nagar, West Marredapalli, Secunderabad, Andhra
Pradesh. SPC is proposing 10000TPA facility for PLA in Andhra Pradesh. Project is
supported by DST and DBT. SPC has developed a novel & cost effective technology for
the manufacture from Agriwaste (under patenting).
27. 27
(4) US-based bioplastic resins manufacturer Cereplast has launched its products in the
Indian market, unveiling plans to set up a manufacturing unit by 2014. The company
manufactures compostable resins, which can be a substitute for petroleum-based
plastics, and hybrid resins, which can replace up to 55 per cent of the petroleum content
in conventional plastics with bio-based materials such as industrial starch sourced from
plants. The company has tied up with Hyderabad-based marketing firm ARMY Group as
its Indian distributor. It is exploring the possibility of setting up the unit in Kakinada, as it
is close to raw material sources. The plant will have an initial capacity of 50,000 tonnes
per annum, involving an investment of $ 10 million. Currently, Cereplast has a similar
capacity plant in the US and is setting up a second facility in Italy.
(5) Harita NTI Ltd., TamilNadu
(6) Biotec bags, TamilNadu
(7) Greendiamz Biotech Pvt. Ltd, manufacturer of environmentally safe plastic products, has
set up its first unit to manufacture sheets and bags dedicated to only bioplastic here
recently. The sheets produced are termed as ―Bioplastic‖ – Bio as it is 100%
biodegradable and compostable and it is very similar to plastic in terms of strength and
usage. The product is branded as Truegreen that will serve as an alternative to plastic
for consumer and industrial products. ―The product line available with us will not only be
a complete substitute to plastic but shall propel various other benefits to the consumer.
Truegreen will prove a big respite to many pollution control bodies investing huge
amounts on waste management. Truegreen Film is made from Biolice raw material
which is a biodegradable polymer. Biolice is exclusively used by Greendiamz Biotech to
manufacture Truegreen products in Ahmedabad. Biolice benefits from the ―OK Compost‖
and ―Kompostierbar‖ certification, which, in accordance with European Standard EN
13432, guarantees the product‘s complete decomposition in less than twenty four weeks
with no toxic risk to the environment. The bioplastic products manufactured using Biolice
after normal disposal in soil are broken down by micro-organisms. This process which is
traditional and natural for solid waste disposal produces good quality humus, suitable for
use in gardening or agriculture. India‘s first fully bioplastic dedicated sheets and bags
manufacturing unit. The company intends to provide packaging products made out of
fully biodegradable and compostable bioplastic material to the sports brand. It is in talks
with Reebok for packaging of products. The company has signed MOU with the govt of
Gujarat. The company may also provide bioplastic products to the state government.The
company is expecting some subsidies from the Gujarat government.it will be supplying
Truegreen products to the forest department of the government. Greendiamz Biotech
has tied up with French firm Limagrain for sourcing ‗Biolics‘, a biodegradable polymer
used as a raw material. Once the raw material manufacturing technology of Limagrain is
transferred to India, the production cost will come down by 40 per cent. While Truegreen
bioplastic products are priced 3-4 times higher than plastic products, Khajotia said the
former‘s dart strength is three times higher than the latter. The Ahmedabad facility is
spread across an area of 7,200 sq yard. The unit has a capacity to produce 4,000-5,—
tonnes of dedicated bioplastic film, sheets and other products. The unit has been set up
at an investment of Rs 40 crore. By the end of the financial year 2010-11, the company
expects to sell around 1,500 tonnes of bioplastic products through B2B and B2G model.
The central government has removed the 10 per cent custom duty on bioplastic products
for agriculture purpose. It does not include any petroleum product in its manufacturing
cycle, making the product truly environment-friendly. In this product, the soil bacteria will
decompose 95 per cent of this material to carbon, oxygen and non-toxic bio-mass within
180 days.
28. 28
Chapter 5
Bioplastics – Properties and Processing
Comments on Properties of Biopolymers and their Comparison
Physical, mechanical and chemical properties of materials for plastic have effect on their
processibility, utility, durability and biodegradability. Polymers owe their importance to their
outstanding properties such as low density, durability, consistency and flexibility for a wide
range of applications from simple packaging to heavy construction. Plastic polymers are made
up of smaller units called monomers. Monomers are converted into polymers via the
polymerization process. The polymers can then be made into granules, powders and liquids,
which become the raw materials for plastic products. There are 45 different forms of polymers,
each having different chemical composition and properties, making them suitable for a wide
variety of applications. Plastic products are manufactured by a number of methods, all of which
apply heat and pressure to soften the raw material, and then form it into a particular shape and
subsequently cooled to retain the shape. Most commonly used polymers and their uses are:
Sr. No. Polymer Resin Common Use
1 High Density Polyethylene (HDPE) Rigid containers
2 Low Density Polyethylene (LDPE) Package films, bags
3 Polypropylene (PP) Wrappers, linings, boxes, crates
4 Polystyrene (PS) Foams, insulations
5 Polyvinyl chloride (PVC) Rigid containers, films
6 Polyethylene terphthalate (PET) Soft drink containers
7 Polycarbonate (PC) baby bottles, sports water bottles
Conventional plastics provide a broader range of material properties than Poly-lactic acid (PLA)
and Poly-hydroxy-alkonates (PHA), but they are not biodegradable. Plastics can be divided into
two main groups; thermoplastics and thermosets.
Thermoplastic: A material that can be molded and shaped when it‘s heated. Linear polymers
that are not cross-linked and that are not strongly hydrogen-bonded to adjacent polymer chains
generally possess this characteristic. Thermoplastic properties are needed to be able to form a
material by extrusion. Thermoplastics can be melted and reshaped many times over when
heated, and hence can be recycled.
Thermoset: A hard and stiff material. Thermosets are different from thermoplastics,
Thermosets are crosslinked so they are not moldable. Also they are different from crosslinked
elastomers. Thermosets are stiff and don‘t stretch the way elastomers do. Thermosets are like
concrete, because they can only be shaped once. They are usually rigid and will not flow again
even when heated, making recycling very difficult.
Properties of Materials for Plastics
Physical, mechanical, and chemical properties of materials for plastics have effects on the utility
and applications of them. These properties can affect processability, durability, and
biodegradability. While thinking of using bio-based materials for plastics a comparison must be
made of their various properties and possible application.
Earlier biodegradable polymers have been lacking performance properties needed in many of
the areas where biodegradable or 'limited life' polymers are needed. Biodegradable plastics to
29. 29
be introduced must have both the suitable mechanical properties for application as well as
economic feasibility for commercialization.
It can be expected that, following processing and product development of biobased materials,
resulting properties should equal or outperform those of the conventional alternatives. However,
such processing and product development is not always insignificant and is unlikely to be cost
effective in all cases.
Most bio-based materials exhibit some unique specific properties, which may make them
especially suitable in certain applications. Examples of these properties are:
Excellent gas barrier properties
Straight forward processability into foam materials (without chemical blowing agents)
Anti-static properties
Hydrophilic behavior. Therefore these materials are potentially good water-absorbent
materials.
Excellent matrix material for encapsulation of natural ingredients (fertilizers, flavors etc.)
Abundance and low cost
Product development from renewable resources should focus on utilizing their specific
properties, of course taking into account the economics of the production process as well as the
environmental issues from raw materials production up to after use disposal options.
For bioplastics, future developments will focus on films, foams. By making use of unique
properties of natural materials, new markets can be identified. The complete life-cycle of a
product should be considered. A bioplastic-based product should offer an advantage during
production, during use, or in the disposal phase. Nevertheless, the price, performance, and
environmental aspects should always be kept in mind.
Properties of importance while considering their applications:
No. Property Importance Comments
1 Gloss Desired in certain applications
(EPG‘s Depart (PVA
based)
2 Transperancy Desired in certain applications
(Lacca (PLA based) of
Mitsui Chemical)
3 Density
Usefulness in sedimentation in
aquatic environment
(PP – Low, PHB –
High)
4
Transparency to
UV
This can cause chemical oxidation
PE – Transparent,
Soya-based – blocks
UV)
5
Gas barrier
properties
Important in food packaging
(Good in gluten-based
and PV-based
plastics)
6
Oxygen
permeability
This is important in edible polymer
films
7
Water vapor
transmittance
(Resistance expected) Important in
food packaging
Minimum in PP and
PS
8 Modulus
measures as to how well a material
resists deformation
(Low for starch, PHA)
Blend with polymers
fillers
9
Glass transition
temperature
Temperature at which a polymer
changes from hard and brittle to soft
and pliable form. (Important for
Mazin (PLA based
High Tg)
30. 30
processing)
10
Melting
temperature
Materials, which have low melting
point, are not strong enough
(Important for procesability)
11
Hydrophilicity or
Water resistance
Will be useful for use of material as
water-absorbent (Important for
disposable diapers and sanitary
napkins) Hydrolyzable nature is
significant for degradation,
decomposition in right conditions.
(PLA water resistant,
Depart water soluble)
12
Flexural
Strength
Needed to break the sample
(Good in PP, PS, hard
PLA, nylon, Less in
PE)
13 Hardness Procesability affected
14
Antistatic
properties
Suitable for electronic packaging
15
Tensile strength
and elongation
Important for a material that is going
to be stretched or under tension.
(1) Gloss, Transperancy
Gloss and transparency are desired in certain applications. EPG‘d Depart (polyvinyl alcohol
based plastic) has high gloss and also high transparency, making it similar to the types of plastic
used in food packaging. ‖Lacea‖ (Polylactic acid based) of Mitsui Chemicals, Inc. is transparent
and therefore suitable for films. Acetylchitosan (acetylated chitosan) films are more transparent
than the pure chitosan films generated from acetic acid solution.
(2) Density (g/cm3
) is important property when it comes to sedimentation in aquatic
environments which facilitates degradation (PP – Low, PHB – High)
PP – 0.905 to 0.94 Due to low density floats in aquatic system
PHB – 1.23 to 1.25 more density, hence goes to sediment in aquatic system
PLA (CDP) – 1.25
Lignopol – 1.30 – 1.38
Lignocellulosic resources have low densities.
(3) Transperancy to UV
This can cause chemical oxidation. Soy-based biodegradable films have some attractive
properties as packaging materials, including the ability to block ultraviolet light. Polyethylene
films are transparent to UV light, which can produce chemical reactions or oxidations that
deteriorate the quality of the products. UV resistance of polypropylene is also poor.
(4) Gas Barrier Properties (calculated as Log OTR cm3
m/m2
d bar)
Gas Barrier Properties of biobased material are dependent on moisture contents since these
materials are hydrophilic. It increases when humidity increases. Gas barriers based on PLA and
PHA is not expected to be dependent on humidity. Gluten-based packaging films and coatings
can be excellent edible, renewable, and biodegradable air barriers with good mechanical
properties. EPG‘s Depart (Polyvinyl alcohol based plastic) despite being water-soluble it also
has high gas barrier properties so suitable for food packaging.
PP – 860 (cm3
/m2
·24h·atm·25µm)
PVC – 150 (cm3
/m2
·24h·atm·25µm)
LDPE – 18500 (cm3
/m2
·24h·atm·25µm)
Soft PLA – 820 (cm3
/m2
·24h·atm·25µm)
Hard PLA – 380 (cm3
/m2
·24h·atm·25µm)
Ecoflex – High,
31. 31
Wheat gluten/water/glycerol – Medium,
Amylose/glycerol – Medium,
PVDC – Low,
Chitosan (plasticized) – Low,
Whey/water/glycerol – Medium
(5) Oxygen permeability of edible polymer films – Units is cm3
·um/(m2
·d·kPa)
Oxygen permeability is important in edible polymer films.
LDPE – 1870
HDPE – 427
Cellulose based – MC – 90, HPMC – 272
Starch based – 0 – 65
Protein based – Low
(6) Water vapor transmittance (calculated as log WVT (g/m2
/d)
Applications in food packaging demand materials that are resistant to moist conditions. Water
vapour resistance of biobased materials is comparable to that of conventional plastics. If higher
than that water vapor barrier material is required, very few biobased materials are useful. Main
problem then is in food packaging. Eastman (Eastar Bio), is a tough, liquid impermeable
material and is suitable for flexible film and coating applications.
Water vapor permeability coefficient of acetylchitosan (acetylated chitosan) increased with
increasing the degree of O-acetylation. The water vapor permeability is much higher than
commercial packaging films.
PP – 9 (g/m2
·24h·25µm)
PS – 30 (g/m2
·24h·25µm)
Soft PLA – 740 (g/m2
·24h·25µm)
Hard PLA – 330 (g/m2
·24h·25µm)
LDPE – 20 (g/m2
·24h·25µm)
Ecoflex – Medium,
Wheat gluten/water/glycerol – high,
PA6 – Medium, PVDC – low,
Chitosan (plasticized) – high,
Whey/water/glycerol – high
(7) Modulus
The mechanical properties in terms of modulus and stiffness are not very different compared to
conventional polymers. Elastomers need to show high elastic elongation. But for some other
types of materials, like plastics, it is usually better that they do not stretch or deform so easily.
Modulus measures as to how well a material resists deformation. Modulus is measured by
calculating stress and dividing by elongation, and would be measured in units of stress divided
by units of elongation. Fibers have the highest tensile moduli, and elastomers have the lowest,
and plastics have tensile moduli somewhere in between fibers and elastomers. From stress-
strain curves (strain = % elongation) it can be seen that plastics like polystyrene,
polycarbonates and poly (methyl methacrylate) can withstand a good deal of stress, but they
won't withstand much elongation before breaking. All these materials like this are strong, but not
very tough. These are rigid plastics as they have high moduli. Rigid plastics tend to be strong,
resist deformation, but they tend not to be very tough, thus, they're brittle. Flexible plastics like
polyethylene and polypropylene are different from rigid plastics in that they don't resist
deformation as well, but they tend not to break. Initial modulus is high, that is it will resist
deformation for a while, but if enough stress is put on a flexible plastic, it will eventually deform.
Flexible plastics may not be as strong as rigid ones, but they are a lot tougher. Addition of
plastizers makes plastics more flexible.
Modulus of bio-based materials ranges from 2500-3000MPa and is lower (50MPa) for
thermoplastic starches (stiff materials) and also low (50MPa) for PHA (rubbery materials).
32. 32
Plasticizing, blending with other polymers or fillers, cross-linking, or addition of fibers etc can
tailor the modulus.
Flexural modulus of PP – 880MPa
Flexural modulus of PS – 3040MPa
Flexural modulus of soft PLA – 1040MPa
Flexural modulus of hard PLA – 2550MPa
Vegemat® can be injected or extruded at down to 1 mm thickness with no particular difficulty at
a temperature of between 130 and 140°C. In addition, it has mechanical properties that are very
close to those of polyethylene and polypropylene. Its traction and bending strength is
respectively at 22MPa and 35MPa and its elasticity modulus attains 2,800MPa. These qualities
are mainly due to the fibers contained in the polymer, and in particular in one of their
components, hemicellulose.
The mechanical properties of PLA are comparable to those of polystyrene with an elasticity
modulus of 3500MPa, a maximum tensile strength of 50MPa, and an elongation at break of 4%.
(8) Glass transition temperature (Tg degree centi)
Glass transition temperature is the temperature at which a polymer changes from hard and
brittle to soft and pliable. Thermal and mechanical properties of the materials are both important
for processing and also during the use of the products derived from these materials. Most bio-
based polymers perform in similar fashion to conventional polymers. Thus polystyrene-like
polymers (relatively stiff materials with intermediate service temperatures), polyethylene-like
polymers (relatively flexible polymers with intermediate service temperatures) and PET-like
materials (relatively stiff materials with higher service temperatures) can be found among the
available bio-based polymers. MAZIN (PLA based) advantages include: Higher glass transition
temperature (high temperature strength) properties than other commercially available
biopolymer resins.
Disadvantage of PLA is to become too soft above its glass transition temperature (600
C), which
limits its applications.
Urea with different concentrations may be used to modify the soy protein and that improves its
plastic performance. Tg is increased as urea concentration increased, however, it is still lower
than the unmodified proteins.
PP - -10
Soft PLA – 51
Hard PLA – 60
PLA – 60 (Drawback for pure PLA)
Starch-PLA blend – 60,
Cellulose diacetate – 120-140,
PET – 80,
Thermoplastic starch – 40-60,
Polyester amides - -20,
Proteins – 40
(9) Melting temperature (degree centi)
Materials, which have low melting point, are not strong enough. A new degradable polymer is
prepared by blending up to 45% starch with degradable polycaprolactone (PCL). This new
material is not strong enough because the melting temperature of PCL is only 600
C. Also, PCL
gets soft when temperature is above 400
C. These drawbacks greatly limit the applications of the
starch-PCL blends. On blending of starch with polyvinyl alcohol and ethylene vinyl alcohol
degradable films with low melting temperature in the range of 40 to 1300
C have been prepared.
PET – 260,
Polyester amides – 125-190,
Aliphatic copolyester – 75,
PCL – 70,
33. 33
PCL-starch blend – 70.
(10) Hydrophilicity or Water resistance
Property of hydrophilicity will be useful for use of material as water-absorbent and applications
can be in disposable diapers and sanitary napkins. Hydrolyzable nature is significant for
degradation, decomposition in right conditions.
Synthetic hydrophobic biodegradable polymers have low rate of degradability. Blending starch
with such material is of interest.
Urea with different concentrations was used to modify the soy protein and improve its plastic
performance. The plastics made from modified proteins showed lower water absorption than
unmodified proteins during 24h soaking. Minimum water absorption was observed at 1M urea
modification for 2h soaking and 2M-urea modification for 24h soaking.
Polyglycolic acid – Hydrolyzable
Polylactic acid – Hydrolyzable
Polycaprolactone – Hydrolyzable
PHB – Hydrolyzable
PHBV – Hydrolyzable
PVOH – Water-soluble
Polyvinyl acetate – Water-soluble
Polyenyl ketone (derived from PVOH) – Water-soluble
RADEMATE Ltd‘s Rapidly-Biodegradable Hydrophobic Material (RBHM) (cellulose-based
material is hydrophobic.
PLA is water resistant but cannot withstand high temperatures (>55°C). Although PLA is not
water soluble, microbes in marine environments can also degrade it into water and carbon
dioxide.
Water absorption of the starch-PLA blend is less than 10% after ten days of water soaking test.
Properties of ‗Depart‘ a polyvinyl alcohol based plastic (fully biodegradable) from Warrington-
based Environmental Polymers (EPG), can be changed making it soluble in water at
predetermined temperatures from 15 to 800
C. The material is suitable for laundry bags (hospital
linen goes straight in washing machine while still in packaging bags) and compostable waste
bags. The material is stable otherwise and decomposes only in composting conditions. The
material is stable otherwise and decomposes only in composting conditions.
Another recent discovery is a class of oyster molecules with super-absorption properties,
soaking up 80 or more times their weight in water. This discovery could result in the
replacement of non-biodegradable super-absorbents in disposable diapers and sanitary
napkins.
(11) Flexural Strength, PSI
Strength is the stress needed to break the sample.
A polymer sample has flexural strength if it is strong when one tries to bend it.
"Sweet Plastic" - 7,000-14,000,
Low-density polyethylene - 1,000-4,000,
High-density polyethylene - 3,000-5,000,
Polypropylene - 5,000-8,000, (25 MPa)
Impact polystyrene - 10,000-14,000, (47 MPa)
ABS copolymer - 6,000-14,000,
Nylon - 7,000-15,000
Flexural strength of soft PLA – 34 MPa
Flexural strength of Hard PLA – 83 MPa
(12) Tensile strength and elongation
Strength is the stress needed to break the sample. Tensile strength and elongation are two
major mechanical properties for a plastic to have market potential. Tensile strength is important
for a material that is going to be stretched or under tension. A polymer has tensile strength if it is
34. 34
strong when one pulls it. The tensile strength gives important information on mechanical
properties of biodegradable polymers. Tensile strength is a measure of the ability of a polymer
to withstand pulling stresses before breaking (force/cross-sectional area). Elongation is the %
change in length experienced by a material due to pulling stress before breakage.
Strength tells us as to how much stress is needed to break something. It doesn't tell us anything
about what happens to sample while we're trying to break it. Study of the elongation behavior of
a polymer sample tells us as to what happens to sample when we try to break it. Elongation is a
type of deformation. Deformation is simply a change in shape that anything undergoes under
stress. When we're talking about tensile stress, the sample deforms by stretching, becoming
longer. This is referred to as elongation. Ultimate elongation is important for any kind of
material. It is nothing more than the amount you can stretch the sample before it breaks.
Elastomers have to be able to stretch a long distance and still bounce back. Most of them can
stretch from 500 to 1000% elongation and return to their original lengths without any trouble.
The strength of the protein-starch (corn-starch and various proteins) thermoplastics was fairly
good. Sisal fiber-reinforced composites show high impact strength, moderate tensile and
flexural properties compared to other cellulosic fibers.
Plastics made from native soy protein are rigid and brittle. Urea with different concentrations
was used to modify the soy protein and improve its plastic performance. Tensile strength of the
soy protein plastics increased as urea concentration increased from 1M to 8M. The 2M urea
modified soy protein had similar tensile strength as the unmodified soy protein, but about 70
times higher elongation than the unmodified proteins.
Plastics made from this treated material (soy protein was treated with acid at pH 4.5) displayed
an increased water resistance and a similar tensile strength as that of unmodified protein
plastics.
Acetylation of soy protein isolate was found to weaken the tensile properties of the plastics;
however, the molding temperature range of acetylated soy protein was substantially lower than
that of unmodified soy protein.
Tensile strength and elongation decreased as the degree of O-acetylation increases in
preparation of acetylated chitosan.
The elongation for pure PLA is about 6%,
The elongation at break for PLA is 30.72%
The elongation at break for Mazin is 30.72%
The elongation of the starch/PLA blends was about 4.5%, which is brittle for many packaging or
fast food utensil materials.
Tensile strength of PP – 25 MPa
Tensile strength of PS – 47 MPa
Tensile strength of PVC – 50 MPa
Tensile strength of Maxin is – 32.22 MPa
Tensile strength of pure PLA – 64 MPa (50 MPa)
Tensile strength of Starch:PLA = 50:50 wet base – 61 MPa (0.5% chemical added for diblock
formation in reactive blending of wheat starch and PLA)
Tensile strength of Starch:PLA = 50:50 wet base – 30 MPa (without addition of 0.5% chemical
added for diblock formation in reactive blending of wheat starch and PLA)
(13) Hardness
PLA is a hard material, similar in hardness to acrylic plastic with hardness on the Rockwell H
Scale of more than 60. Therefore, when we extrude a pure PLA sheet and a die is used to cut
out the product being printed, the cutting edge of the die wears out rapidly. In addition, due to
the hardness, the PLA fractures along the edges creating a product that cannot be used. To
overcome these limitations PLA has to be compounded with materials to adjust the hardness
and eliminate the fractures when the material is die cut. Mazin‘s (PLA based polymer) hardness
(which can be altered easily) is approximately 20.6 on the Rockwell H Scale. Printers who have
35. 35
worked with it have found the stiffness of the card acceptable and die wearing almost
eliminated.
Chronopol‘s proprietary, patented process yields high quality, polymer-grade lactide with
unmatched isomeric purity. This exceptional monomer, forms a highly isotactic polymer. The
purity and specificity of the lactide monomer provide precise control over the polymer structure,
allowing unprecedented control of properties. The result: Applications can be as hard as acrylics
or as soft as polyethylene, as stiff as polystyrene or as flexible as an elastomer. And the
polymer is fully degradable, compostable, and nontoxic, with a variety of degradation rates and
shelf-lives.
Ethylene vinyl alcohol is stronger than polythene, has anti-static properties, which make it
similar to some nylons (and therefore suitable for electronics packaging).‖Lacea‖ of Mitsui
Chemicals, Inc. is hard and is one of the important properties while looking for certain
applications like household wraps, cooking papers, cosmetic containers, agricultural films,
garbage bags.
The extrusion of commercial rapeseed meal with formol makes a material with interesting
hardness properties, which could be used for elaboration of 3D objects. Mechanical properties
of these objects can be modified by glycerol.
Processing of thermoplastic material
No. Processing Method Comments
1 Injection Molding
2 Blow Molding
To form hollow articles. It is a process of forming a
molten tube of thermoplastic material, then with the
use of compressed air, blowing up the tube to
conform to the interior of a chilled blow mold.
3 Thermoforming
It consists of heating thermoplastic sheet to a
formable plastic state and then applying air and/or
mechanical assists to shape it to the contours of a
mold
4 Transfer Molding
Most generally used for thermosetting plastics. This
method is like compression molding in that the plastic
is cured into an infusible state in a mold under heat
and pressure.
5
Reaction Injection
Molding
Less energy requiring relatively new technique in
which two or more liquids are mixed just before
casting.
6 Extrusion
Method employed to form thermoplastic materials into
continuous sheeting, film, tubes, rods, profile shapes,
and filaments, and to coat wire, cable and cord. Dry
plastic material is heated and molten plastic is forced
out through a small opening or die with the shape
desired in the finished product
Processing of Bio-based Polymers
(1) The development of multi-layer (barrier) films for applications such as food packaging is
desired. In many food applications, both a water vapour barrier as well as a gas barrier is
required. No single biobased polymer can fulfil both these demands. In this case the use of co-
extrusion can lead to laminates, which meet the objectives. A range of melt-processable starch
