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chemistry of hair

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    1. 1. Chemistry of Hair<br />By: Marlene Simas, Tavis Cano, and Kathleen Good<br />
    2. 2. Hair Structure<br />Made up of 3 layers<br />Cuticle<br />Outer covering<br />Cortex <br />Elasticity <br />Curl <br />Medulla<br />Body temperature regulation<br />
    3. 3. Hair Composition<br />88% is made up of proteins <br />Mainly Keratin<br />Many polypeptide chains<br />Broken down = individual amino acids<br />Right combo = specific protein<br />Natural Hair pH is 5<br />
    4. 4. A Helix Coil<br />1 hair = 3 “alpha helices”  protofibril<br />9 protofibrils bundled in a cirle  11 stranded cable microfibril<br />100s of microfibrils in a bundle  macrofibril<br />Cortex of hair fiber<br />
    5. 5. Natural Hair<br />
    6. 6. Keratin<br />Alpha helix polypeptide chain in human hair<br /> 3.6 amino acids per turn in the helix<br />Peptide bond<br />Between the Carbon and Nitrogen<br />
    7. 7. Bonding in Keratin Protein<br />
    8. 8. Bonding <br />Hydrogen bond: Is between the coils of the alpha helix <br />Can change the shape of hair<br />Elasticity <br />Salt bond: An ionic bond between side chain of the basic to the side chain of an acidic amino acid<br />Happens parallel to the hair <br />Strength and elasticity<br />
    9. 9. Bonding cont.<br />Cystine Bond: Formed by the crosslinks between cystine residues (amino acids) of the main polypeptide chains <br />perpendicular to the hair & between polypedptide chains<br />Strength<br />1 Cystine bond every 4 turns of the alpha helix<br />Sugar Bond: Is between side chain of an amino <br /> acid with OH group and acid amino group<br />Perpendicular to the hair<br />Toughness and some strength<br />
    10. 10. How Shampoo Works<br />
    11. 11. Shampoo<br />Surfactants:<br />Essential cleaning substances <br />Determines cleansing and lathering characteristics <br />cleansing, foam, condition, viscosity and aesthetic appeal combined with safety and mildness in use.<br />
    12. 12. Surfactants <br />Are divided based on the hydrophilic head<br />Anionic: negative charge<br />Cationic: positive charge<br />Amphototeric – positive and negative charge<br />Nonionic – no charge<br />
    13. 13. Sodium Lareth Sulfate<br />
    14. 14. Conditioners<br />Are cationic<br />Do not rinse out completely<br />Leave hair coated with thin film<br />Hydrophobic head is what gives hair conditioning ability; smoothing the hair and giving it weight <br />6 categories:<br />Moisturizers<br />Reconstructors<br />Acidifiers <br />Detanglers<br />Thermal Protection<br />Glossers <br />Oils <br />
    15. 15. Hexadecyltrimethylammoniumchloride<br />Are usually quaternary ammonium compounds <br />4 R groups to 1 N<br />Can also be tertiary <br />Form the thin coating on the hair shafts <br />Hexadecyltrimethylammonium<br />chloride<br />PEG-12 DIMETHICONE<br />
    16. 16. CG Method! <br />Lorraine Massey <br />NO SHAMPOO <br />All products used – conditions, gels, creams, sprays, etc – are all free of<br />Sulfates<br />Silicones: -cone, -conel, -xane<br />Can have any hair type to try<br />
    17. 17.
    18. 18. Wet hair stretches as the temporary hydrogen bonds are broken <br />When blow dried will return to the alpha keratin shape<br />
    19. 19. Brazilian Blow Out<br />
    20. 20.
    21. 21. What’s In It?<br />Formaldehyde<br />Methylene Glycol<br />Glutaraldehyde<br />
    22. 22. Formaldehyde; What is it?<br />Organic compound CH2O<br />Simplest Aldehyde<br />IUPAC name: Methanal<br />Systematic name: Formaldehyde<br />Colorless gas with a pungent odor<br />Important in polymers<br />Used as disinfectants<br />Used for preservation of biological specimens <br />Widespread use: toxicity, volatility, carcinogenic <br />Other names: Formal, Methlyaldehyde, Methylenegylcol, Methylene Oxide <br />
    23. 23. Formaldehyde<br />Russian chemist AleksandrButlerov & August Wilhelm von Hofmann<br />Produced by catalytic oxidation of methanol<br />Most common catalysts: Silver, iron,<br />2 CH3OH + O2 -> 2 CH2O + 2 H2O<br />CH3OH -> H2CO + H2 (dehydrogenation) <br />
    24. 24. Cont. <br />Building block<br />Highly reactive<br />Tissue fixative<br />“My eyes were irritated for a week or so after the treatment & my hair burned my boyfriends nose...”<br />
    25. 25. Properties Of Formaldehyde<br />Molecular formula: CH2O <br />Molar mass: 30.03 g mol−1<br />Exact mass: 30.010564686 g mol-1<br />Appearance Colorless gas <br />Density: 1.38 g cm-3<br />Melting point: -92 °C, 181 K, -134 °F<br />Boiling point: -21 °C, 252 K, -6 °F<br />Solubility: in water 400 g dm-3<br />log P: 0.350 <br />Acidity: (pKa) 13.3 <br />Basicity: (pKb) 0.7 <br />Dipole moment: 2.33 D Structure <br />Molecular shape: Trigonal planar<br />
    26. 26. Health Effects of Formaldehyde<br />Runny nose<br />Sore throat<br />Cough<br />Sleeping difficulties<br />Headache<br />Fatigue<br />Breathing difficulties<br />Sinus irritation; nose bleed<br />Chest pain<br />Decreased lung capacity<br />Bronchitis<br />Nausea <br />Abdominal pain<br />Anxiety<br />Coma<br />Convulsions<br />Diarrhea<br />Respiratory problems (pneumonia)<br />Dizziness<br />Drowsiness<br />Low Level Exposure<br />Acute Exposure<br />
    27. 27.
    28. 28. Methylene Glycol<br />Also known as Formaldehyde monohydrate or methylene glycol<br />Chemical formula: CH4O2, or H2C(OH)2<br />
    29. 29. Cont.<br />Is a product of the hydration of formaldehyde <br />Predominates in water solution<br />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<br />
    30. 30. Glutaraldehyde…What is it?<br />Pungent & oily liquid at room temperature<br />IUPAC name: Pentene-1,5-dial<br />Other names: Pentanedial, Glutardialdehyde, Glutaricdialdehyde<br />Used to disinfect medical and dental equipment <br />Organic compound<br />Formula: CH2(CH2CHO)2<br />
    31. 31. Cont.<br />Produced by oxidation of cyclopentene<br />Used in biological electron microscopy as fixative<br />
    32. 32. Health Effects<br />Sever eye, nose, throat and lung irritation <br />Headaches<br />Drowsiness<br />Dizziness<br />Main source of occupational asthma<br />
    33. 33. Perm<br /> Perm<br />
    34. 34. Ammonium thioglycolate<br />A solution containing ammonium thioglycolate contains a lot of free ammonia, which swells hair<br />In the perm solution reduces the disulfide cystine bonds in the hair. <br />It removes crosslinks. After washing, the hair is treated with a mild solution of hydrogen peroxide, which oxidizes the cysteines back to cystine. <br />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. <br />Not all disulfides are reformed<br />Result: the hair is weaker than before the permanent was applied and repeated applications over the same spot may eventually cause strand breakage<br />
    35. 35. Permanent Hair Wave<br />Disulfide bond formation can produce curls in hair by the permanent wave process<br />Hair keratine=many protein alpha helices<br />3 alpha-helices interwoven in coil=protofibril<br />11 protofibrils bonded and coiled together=microfibril<br />Hundreds of microfilbrils cemented into buncle=macrofibril<br />
    36. 36. Disuldife Bonds in Hair<br />Formed by oxidation of sulfhydrl groups on cysteine<br />Different protein chains loop within a single chain & help by strong covalent disulfide bonds<br />
    37. 37. Reducing Agent<br />Perming requires a basic reducing substance: Ammonium Thioglycolate<br />Added to reduce/rupture some disulfide cross-links<br />
    38. 38. The Results<br />Since the alpha-helices are ruptured and no longer tightly cross-linked, the alpha helices can shift positions<br />Rollers or curlers or inserted<br />Oxidizing agent is added to reform bonds into new positions<br />
    39. 39.
    40. 40. Structure of Hair <br /><ul><li>Outer layer of hair shaft is called the cuticle
    41. 41. consists of many microscopic scales
    42. 42. when they are aligned they give the appearance of shiny hair</li></li></ul><li>Hair Color <br /><ul><li>Natural color of hair depends on 
    43. 43. The ratio and quantities of 
    44. 44. Eumalinen and Phaeomelanine
    45. 45. These two make up only 1% of hair structure
    46. 46. Phaeomelanine is resposible for red to blonde colors 
    47. 47. Eumalinen make brown to black shades of hair
    48. 48. While you can have one or both, the absence of both results in white/grey hair</li></li></ul><li>Bleaching<br /><ul><li>Bleaching is a process used to strip color from hair and can be done for three reason
    49. 49. Highlighting is a cosmetic effect of lightening streaks or sections of hair
    50. 50. Blonding is a process that strips away original color and adds color to hair to achieve blonde appearance
    51. 51. Usually achieved by a mixture of bleach and a coloring agent 
    52. 52. Precoloring makes hair a blank canvas which makes hair color applied after words brighter</li></li></ul><li>Bleaching<br /><ul><li>Cosmetic bleaches use the oxidizing effects of hydrogen peroxide
    53. 53. A low volume of peroxide (5-30%) in a cream form combined with powder bleach creates a blue paste
    54. 54. this is applied and left until desired amount of color is stripped from hair then rinsed out
    55. 55. usually has a pH of 8 or 9</li></li></ul><li>Bleaching<br /><ul><li>For bleach to change the color of hair it has to be able to penetrate below the cuticle surface
    56. 56. Usually done by mixing bleach component with a alkaline solution (often ammonia)
    57. 57. This alkali swells the hair fiber causing cuticles to separate and open, allowing bleach to penetrate the cortex </li></li></ul><li>Bleaching   <br /><ul><li>Bleach reacts more readily with dark eumelanin pigments than with phaeomelanin pigments
    58. 58. If hair has been previously colored with permanent dye bleaching could vary in effectiveness </li></li></ul><li>Bleaching<br /><ul><li>Bleaching is very damaging to hair as well as emitting a sulfuric odor
    59. 59. Hydrogen peroxide breaks the sulfur bonds which releases larger amounts of sulfur
    60. 60. This causes hardening, loss of mass, and produces smell
    61. 61. minimized by using low levels of peroxide in cosmetic bleach
    62. 62. If using metal implements to apply bleach they can oxidize, the reaction following this with bleach can turn hair green</li></li></ul><li>
    63. 63. Hair Dye<br /><ul><li>Three types of hair dye
    64. 64. Temporary - lasts 1-3 washes and involves no chemical reactions with the hair 
    65. 65. Pigments are applied to surface without penetrating further
    66. 66. Semi-permanent - stays in 5-15 washes usually made from vegetable dyes, mainly designed to adhere tightly to cuticle surface
    67. 67. no chemical reactions take place</li></li></ul><li>Hair Dye<br /><ul><li>Types of hair dye cont.
    68. 68. Permanent  - lasts indefinitely until hair grows out or chemically treated to remove color 
    69. 69. First safe permanent hair dye created in 1907 by Eugene Schueller
    70. 70. Main ingredient was paraphenylenediamine
    71. 71. Often combines bleaching and coloring agent
    72. 72. Dye molecules enter the hair cortex where they react and become trapped as the cuticles close
    73. 73. A post coloring conditioner is used to encourage cuticles to close and realign to make color last longer</li></li></ul><li><ul><li>Basic Orange 31
    74. 74. 2-[(4-aminophenyI)azo] -1,3- dimethyl - 1H-               Imidazolium Chloride
    75. 75. C11H14N5Cl
    76. 76. Basic Brown 16
    77. 77. 8-[(4-Amino - 1 Phenyl)azo] -7 - hydroxy N,N,N Trimethyl - 2 - Naphthalenaminium Chloride
    78. 78. C19 H21N4 OC1</li></li></ul><li>Hair Dye<br /><ul><li>Mechanism of permanent hair dye involves three steps</li></ul>Oxidation of 1,4 - diaminobenzene derivative to the quinone state<br />Reaction of this Diimine with a coupler <br />Oxidation of the resulting compound to gives the final dye<br />
    79. 79. Hair Dye<br /><ul><li>Adverse effects include
    80. 80. Temporary skin irritation and allergies
    81. 81. Hair breakage
    82. 82. Skin discoloration
    83. 83. And unexpected hair color results</li>
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