ChemistryYou will learn about:

•Matter

•pH Scale

•Chemistry of Cosmetics

Why Chemistry?The professional cosmetologist needs to

understand the chemicals he/she works with in order to:

- safely perform chemical services requested by clients,

- teach clients how to care for their hair following chemical services,

- and, sell products to their clients.

Matter• Anything that occupies

space; exist in 3 forms:– Solids – weight,

volume, shape– Liquids – weight,

volume, no shape– Gasses – weight,

indefinite volume and shape

Liquid

Gas

Organic Matter• Matter that is now living or was alive at

one time.– Ex. - Plants and animals

Plants and Mulch Humans Animals

Inorganic Matter• Matter that is NOT alive or has never been

alive; does not contain carbon.– Ex. – rocks, water, minerals

Rock – Granite Water Mineral - Quartz

Changes In Matter• Physical Change

– Change the characteristics without making a new substance.

• Ex. – Ice Melting

• Chemical Change– A change in a substance that

creates a new substance with chemical characteristics different from those of the original substance.

• Ex. – Rust – oxygen mixed with metal creates rust (or iron oxide)

Elementsthat make up hair# Element Symbol Form

6 Carbon C Solid

8 Oxygen O Gas

1 Hydrogen H Gas

7 Nitrogen N Gas

16 Sulfur S Solid

Anatomy of a Hair Strand

Atoms• Smallest complete unit of an

element.

• Atoms combine chemically to form

• of amino acids.

Molecules

Amino Acids• Compounds of

C,O,H,N

• 22 Common amino acids

• Join together in chains to make proteins

Protein• Hair is made up of protein

called keratin

• Hair is 97% keratin and 3% trace minerals

• Hair contains 19 of 22 common amino acids.

End Bonds(Peptide Bonds)

• Backbone of all protein molecules

• Links the amino acid protein chains together end to end.

• Do not disturb the end bond, this could destroy the protein structure.– If broken, protein chains separate into small

fragments, or revert to groups of amino acids that no longer have the characteristics of hair.

• RESULT – VERY DAMAGED HAIR!

Amino Acid Chains are held together by 3 side bonds:

• Hydrogen Bond:– Makes up about 35% of hairs strength.– Individually very weak and can easily be broken

by heat or water to create physical (temporary) changes in the hair.

• Salt Bond:– Also broken by water to create physical (temporary)

changes in the hair.

• Disulfide Bond:– Most important to a Cosmetologist

• Much stronger than hydrogen or salt bonds.• Not broken by heat or water. Only a chemical change.

– Example – permanent wave

How the Side Bonds Work

Salt Bond

Disulfide Bond

Hydrogen Bond

Amino Acid Chain

How Hydrogen and Salt Bonds are Broken by Water

Water molecules can easily break hydrogen and salt bonds when the

water molecules move in between the bonds. When the water molecules are not present the hydrogen and bonds

come back together.

H H2O H H2O H H2O H H2O H H2O H

Hydrogen Bonds broken by water molecules

Stages of Hair Formation

1.Begins with individual atoms.

2.Unite to become molecules of amino acids.

3.Amino acids unite to form peptide or end bonds.

4. Amino acids create polypeptide protein chains.

5. The individual protein chains bond to other chains by hydrogen bond, salt bonds and disulfide bonds.

6. Hair

Hair Shaft

Cuticle Layer

Close Look at the Cuticle Layer

Chemistry of Cosmetics

• Cosmetic Classifications

–Based on how well a substance combines and its physical characteristics

Solutions• Mixture of 2 or

more kinds of molecules

–Do not separate

–Can be solid, liquid or gas

Suspensions• Mixture of 2 or

more kinds of molecules

• Separates

• Needs to be shaken

–Example: Vinegar and Oil

Emulsions• 2 or more non-mixable substances united

by a binder (gum).– Example: oil in water (perms)– Example: water in oil (cold cream)

Ointments• Mixture of organic

substance and a medicinal agent

• Semi-solid form

• No water

–Example: Lipstick

Soaps

Mixtures of fat and oil converted to fatty acids by heat and then purified.

Powders• Equal mixtures of

inorganic and organic substances that do NOT dissolve in water.

• Sifted and mixed until free of coarse grit.

Shampoo• Cleans the scalp

and hair

• Removes all foreign debris without adversely affecting scalp and hair.

How Shampoo Works• A push pull action is caused by a

surface active agent causing the oil to “roll up” into droplets that are lifted and rinsed away.

Surfactant•Surface active agent

•Has water loving and oil loving ends.

Water LovingOil Loving

Surfactant Molecule

The tail of the shampoo molecule is attracted to oil and dirt

Shampoo causes oil to roll up into small globules

During rinsing, the heads of the shampoo molecules attach to water

molecules and cause debris to roll off.

Thorough rinsing washes away debris & excess shampoo.

The Role of Water

• Universal solvent

• Neutral pH

• Hard water = minerals

–Hard to lather

• Soft water preferred (allows lather)

Types of Shampoos

All Purpose

• Low Alkaline

• Low surfactants

• Mild, does not strip color–Example: Redken Clear

Moisture

Plain• Usually strong

• High alkaline

• Not for chemically treated hair

• Follow with acid rinse– Ex: Baby shampoo

• Doesn’t burn eyes because it’s high in alkaline and so are eyes.

Soapless Shampoo• Able to lather

without harsh alkaline ingredient

• Works in soft and hard water

Acid - Balanced• Made to have same

pH as the skin and hair

• Will not strip color

Medicated• Often must have

prescription

• Designed to treat scalp and hair problems

Clarifying

• Removes residue

–Such as product build-up.

Anti-Dandruff• Control dandruff

• Massage scalp vigorously and rinse thoroughly

Liquid Dry• Used when client

can’t receive normal shampoo

• Works with wigs

• Evaporates from hair

• Very drying

Powder Dry• For bedridden

clients

• Orris root powder absorbs oil and dirt as product is brushed through the hair.

• Don’t use prior to chemical service.

Conditioning• Contain animal,

vegetable or mineral additives that enter cortex or coat cuticle.

• Improve strength and porosity.

Color• Contain temporary

color molecules that stick to outer cuticle of hair.

For Thinning Hair• Gentle

• Lighter molecular weight

• Provides healthy environment for hair growth.

Rinses and Conditioners

Appearance Rinses and

Conditioners give hair the appearance of Shine and Luster

PorosityPorosity - Amount of moisture in the

hair.

Hair Porosity is the ability of the hair to retain & absorb moisture, determined by how raised or compact the cuticle layers are.

Porosity Test

ManageabilityHow easily a comb passes through the

hair.

ElasticityThe hairs ability to stretch and return to its

natural shape without breaking.

Types of Rinses

Vinegar and Lemon Rinse

• Acid rinses

• Remove soap scum

• Counteract alkalinity.

Cream Rinse• Soften

• Add luster

• Only slightly acidic

Medicated RinseControl dandruff and minor scalp

conditions.

Conditioners

Instant Conditioner• Coat the hair shaft

• Restore moisture and oils

• Do NOT penetrate into the cortex

• Not for fine limp hair

Normalizing• Contain

vegetable protein

• Acidic pH causes cuticle to close after chemical services.

Body-Building• Required for

fine, limp hair• Deposits

protein• Can use prior to

chemical services

Moisturizing• Humectants bind

and hold moisture in the hair.

• Avoid use for several days following perm (may go limp)

Customized• Formulated to

meet special needs

• Ex. Moisture and color