chemistry of hair

1. Chemistry of Hair By: Marlene Simas, Tavis Cano, and Kathleen Good

2. Hair Structure Made up of 3 layers Cuticle Outer covering Cortex Elasticity Curl Medulla Body temperature regulation

3. Hair Composition 88% is made up of proteins Mainly Keratin Many polypeptide chains Broken down = individual amino acids Right combo = specific protein Natural Hair pH is 5

4. A Helix Coil 1 hair = 3 “alpha helices”  protofibril 9 protofibrils bundled in a cirle  11 stranded cable microfibril 100s of microfibrils in a bundle  macrofibril Cortex of hair fiber

5. Natural Hair

6. Keratin Alpha helix polypeptide chain in human hair 3.6 amino acids per turn in the helix Peptide bond Between the Carbon and Nitrogen

7. Bonding in Keratin Protein

8. Bonding Hydrogen bond: Is between the coils of the alpha helix Can change the shape of hair Elasticity Salt bond: An ionic bond between side chain of the basic to the side chain of an acidic amino acid Happens parallel to the hair Strength and elasticity

9. Bonding cont. Cystine Bond: Formed by the crosslinks between cystine residues (amino acids) of the main polypeptide chains perpendicular to the hair & between polypedptide chains Strength 1 Cystine bond every 4 turns of the alpha helix Sugar Bond: Is between side chain of an amino acid with OH group and acid amino group Perpendicular to the hair Toughness and some strength

10. How Shampoo Works

11. Shampoo Surfactants: Essential cleaning substances Determines cleansing and lathering characteristics cleansing, foam, condition, viscosity and aesthetic appeal combined with safety and mildness in use.

12. Surfactants Are divided based on the hydrophilic head Anionic: negative charge Cationic: positive charge Amphototeric – positive and negative charge Nonionic – no charge

13. Sodium Lareth Sulfate

14. Conditioners Are cationic Do not rinse out completely Leave hair coated with thin film Hydrophobic head is what gives hair conditioning ability; smoothing the hair and giving it weight 6 categories: Moisturizers Reconstructors Acidifiers Detanglers Thermal Protection Glossers Oils

15. Hexadecyltrimethylammoniumchloride Are usually quaternary ammonium compounds 4 R groups to 1 N Can also be tertiary Form the thin coating on the hair shafts Hexadecyltrimethylammonium chloride PEG-12 DIMETHICONE

16. CG Method!  Lorraine Massey NO SHAMPOO All products used – conditions, gels, creams, sprays, etc – are all free of Sulfates Silicones: -cone, -conel, -xane Can have any hair type to try

18. Wet hair stretches as the temporary hydrogen bonds are broken When blow dried will return to the alpha keratin shape

19. Brazilian Blow Out

21. What’s In It? Formaldehyde Methylene Glycol Glutaraldehyde

22. Formaldehyde; What is it? Organic compound CH2O Simplest Aldehyde IUPAC name: Methanal Systematic name: Formaldehyde Colorless gas with a pungent odor Important in polymers Used as disinfectants Used for preservation of biological specimens Widespread use: toxicity, volatility, carcinogenic Other names: Formal, Methlyaldehyde, Methylenegylcol, Methylene Oxide

23. Formaldehyde Russian chemist AleksandrButlerov & August Wilhelm von Hofmann Produced by catalytic oxidation of methanol Most common catalysts: Silver, iron, 2 CH3OH + O2 -> 2 CH2O + 2 H2O CH3OH -> H2CO + H2 (dehydrogenation)

24. Cont. Building block Highly reactive Tissue fixative “My eyes were irritated for a week or so after the treatment & my hair burned my boyfriends nose...”

25. Properties Of Formaldehyde Molecular formula: CH2O Molar mass: 30.03 g mol−1 Exact mass: 30.010564686 g mol-1 Appearance Colorless gas Density: 1.38 g cm-3 Melting point: -92 °C, 181 K, -134 °F Boiling point: -21 °C, 252 K, -6 °F Solubility: in water 400 g dm-3 log P: 0.350 Acidity: (pKa) 13.3 Basicity: (pKb) 0.7 Dipole moment: 2.33 D Structure Molecular shape: Trigonal planar

26. Health Effects of Formaldehyde Runny nose Sore throat Cough Sleeping difficulties Headache Fatigue Breathing difficulties Sinus irritation; nose bleed Chest pain Decreased lung capacity Bronchitis Nausea Abdominal pain Anxiety Coma Convulsions Diarrhea Respiratory problems (pneumonia) Dizziness Drowsiness Low Level Exposure Acute Exposure

28. Methylene Glycol Also known as Formaldehyde monohydrate or methylene glycol Chemical formula: CH4O2, or H2C(OH)2

29. Cont. Is a product of the hydration of formaldehyde Predominates in water solution Methanediol is listed as one of the main ingredients of the Brazilian Blowout, even though the California-based manufacturer claims that the product contains no formaldehyde

30. Glutaraldehyde…What is it? Pungent & oily liquid at room temperature IUPAC name: Pentene-1,5-dial Other names: Pentanedial, Glutardialdehyde, Glutaricdialdehyde Used to disinfect medical and dental equipment Organic compound Formula: CH2(CH2CHO)2

31. Cont. Produced by oxidation of cyclopentene Used in biological electron microscopy as fixative

32. Health Effects Sever eye, nose, throat and lung irritation Headaches Drowsiness Dizziness Main source of occupational asthma

33. Perm Perm

34. Ammonium thioglycolate A solution containing ammonium thioglycolate contains a lot of free ammonia, which swells hair In the perm solution reduces the disulfide cystine bonds in the hair. It removes crosslinks. After washing, the hair is treated with a mild solution of hydrogen peroxide, which oxidizes the cysteines back to cystine. New bonds instruct the structural rigidity necessary for a successful perm. The rigidification process is akin to the vulcanization of rubber, where commonly polysulfide linkages are used to crosslink the polymer chains. Not all disulfides are reformed Result: the hair is weaker than before the permanent was applied and repeated applications over the same spot may eventually cause strand breakage

35. Permanent Hair Wave Disulfide bond formation can produce curls in hair by the permanent wave process Hair keratine=many protein alpha helices 3 alpha-helices interwoven in coil=protofibril 11 protofibrils bonded and coiled together=microfibril Hundreds of microfilbrils cemented into buncle=macrofibril

36. Disuldife Bonds in Hair Formed by oxidation of sulfhydrl groups on cysteine Different protein chains loop within a single chain & help by strong covalent disulfide bonds

37. Reducing Agent Perming requires a basic reducing substance: Ammonium Thioglycolate Added to reduce/rupture some disulfide cross-links

38. The Results Since the alpha-helices are ruptured and no longer tightly cross-linked, the alpha helices can shift positions Rollers or curlers or inserted Oxidizing agent is added to reform bonds into new positions

41. consists of many microscopic scales

43. The ratio and quantities of

44. Eumalinen and Phaeomelanine

45. These two make up only 1% of hair structure

46. Phaeomelanine is resposible for red to blonde colors

47. Eumalinen make brown to black shades of hair

49. Highlighting is a cosmetic effect of lightening streaks or sections of hair

50. Blonding is a process that strips away original color and adds color to hair to achieve blonde appearance

51. Usually achieved by a mixture of bleach and a coloring agent

53. A low volume of peroxide (5-30%) in a cream form combined with powder bleach creates a blue paste

54. this is applied and left until desired amount of color is stripped from hair then rinsed out

56. Usually done by mixing bleach component with a alkaline solution (often ammonia)

59. Hydrogen peroxide breaks the sulfur bonds which releases larger amounts of sulfur

60. This causes hardening, loss of mass, and produces smell

61. minimized by using low levels of peroxide in cosmetic bleach

64. Temporary - lasts 1-3 washes and involves no chemical reactions with the hair

65. Pigments are applied to surface without penetrating further

66. Semi-permanent - stays in 5-15 washes usually made from vegetable dyes, mainly designed to adhere tightly to cuticle surface

68. Permanent - lasts indefinitely until hair grows out or chemically treated to remove color

69. First safe permanent hair dye created in 1907 by Eugene Schueller

70. Main ingredient was paraphenylenediamine

71. Often combines bleaching and coloring agent

72. Dye molecules enter the hair cortex where they react and become trapped as the cuticles close

74. 2-[(4-aminophenyI)azo] -1,3- dimethyl - 1H- Imidazolium Chloride

75. C11H14N5Cl

76. Basic Brown 16

77. 8-[(4-Amino - 1 Phenyl)azo] -7 - hydroxy N,N,N Trimethyl - 2 - Naphthalenaminium Chloride

80. Temporary skin irritation and allergies

81. Hair breakage

82. Skin discoloration

83. And unexpected hair color results