Transcript Chp 15 Perm Chemistry

Chemistry
Common product ingredients
Common product ingredients
Alcohol
 Volatile alcohol
 Alkanolamines
 Ammonia
 Glycerin
 Silicones
 Volatile organic compounds

Products

Alcohol
– Evaporating, colorless
liquid
• Obtained by the
fermentation of starch,
sugar & carbohydrates

Alkanolamines
– Substances to neutralize
acids or raise the pH of
many products
• Often used in place of
ammonia due to less
odor

Ammonia
– Colorless gas w/pungent
odor
• Composed of hydrogen &
nitrogen
– Used to raise the pH in
perms, haircoloring &
lightening substances
• Raising the pH allows the
solution to penetrate the
hair
– Ammonium hydroxide &
ammonium thioglycolate
are examples of
ammonia compounds
that are used to raise the
pH
Products

Glycerin
– Sweet, colorless, oily
substance formed by the
decomposition of oils,
fats or fatty acids
• Used as a solvent &
moisturizer in skin &
body creams

Silicones
– Special type of oil used in
hair conditioners & as
water resistant lubricant
for the skin
– Less greasy & form a
‘breathable’ film that
does not cause
comedones (blackheads)
Products

Volatile organic
compounds
– VOCs
– Two or more elements
combined chemically
(compounds) that contain
carbon (organic) &
evaporate very quickly
(volatile)
– Most common used in
hairsprays is SD alcohol
– Most people are familiar
w/ volatile such as
• Isopropyl alcohol
– Rubbing alcohol
• Ethyl alcohol
– Alcoholic beverages
• Nonvolatile oils
– Fatty alcohols
» Cetyl alcohol
» Cetearyl alcohol
» Used in
conditioners
Potential Hydrogen
pH is often discussed with regard to
salon products, it is often one of the
least understood properties
 Understanding what pH is and how it
affects the skin and hair is essential to
understanding all chemical services

Potential Hydrogen

“parts hydrogen “ or “ potential hydrogen “
– pH originated from the French term pouvoir hydrogen or
“hydrogen power”
– Means the relative degree of acidity & alkalinity of a
substance
– Small p represents a quantity
– Capital H represents the hydrogen ion H+
– pH represents the quantity of hydrogen ions
Potential Hydrogen


pH scale is a logarithmic scale
This means that in a pH scale, a change of one whole
number represents a tenfold change in pH
– A pH of 8 is 10 times more alkaline than a pH of 7

A change of two whole numbers indicates a change of
10 times 10, or a one hundredfold change
– A pH of 9 is 100 times more alkaline than a pH of 7

Pure water, w/ a pH of 7, is 100 times more alkaline than
a pH of 5, pure water is 100 times more alkaline than
your hair and skin, even though it has a neutral pH.
– Pure water can cause the hair to swell by as much as 20%
Acids & alkalis

Acids
–
–
–
–
–
Owe their chemical reactivity to the hydrogen ion (H+)
pH below 7.0
Taste sour
Turn litmus paper from blue to red
Contract & harden the hair
• Such as thioglycolic acid used in permanent waving

Alkalis
–
–
–
–
–
–
–
Owe their chemical reactivity to the hydroxide (OH
Terms alkali & base are interchangeable
pH above 7.0
Taste bitter
Turn litmus paper from red to blue
Feel slippery & soapy on the skin
Soften & swell the hair
• Such as chemical drain cleaners & chemical hair relaxers
-) ion
Acid-alkali neutralization reactions

Pure water (HO2O)
– Naturally ionizes to create hydrogen (H+) ions & hydroxide
ions (OH-)
– When acids (H+) & alkalis (OH-) are mixed together in equal
proportions
• They neutralize each other to form water (H20)
• Neutralizing shampoos & normalizing lotions used to neutralize
hydroxide hair relaxers work by creating an acid-alkali
neutralization reaction
Oxidation-Reduction
(Redox) Reactions

Oxidation-reduction (redox) reactions are responsible
for the chemical changes created by
–
–
–
–

Haircolors
Hair lighteners
Permanent wave solutions
Neutralizer
Chemical services would not be possible without
oxidation-reduction (redox) reactions
Oxidation reactions

Chemical reaction
– Combines an element or compound w/ oxygen to produce
an oxide
– When oxygen is added to a substance, some heat is almost
always produced
– Chemical reactions that are characterized by or formed w/
the giving off of heat are called exothermic
– Slow oxidation takes place in oxidation perms neutralizers
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Combustion
– Rapid oxidation of any substance accompanied by the
production of heat & light
• Lighting a match – no fire w/out oxygen
Reduction reactions

Oxidized
– When a substance is combined w/oxygen

Reduced
– When oxygen is subtracted from a substance

Reduction
– Chemical reaction

Oxidizing agent
– Releases oxygen
– Hydrogen peroxide example
Redox reactions

Redox
– Contraction for reduction-oxidation
– Oxidation & reduction always occur at the same time

Permanent waving is an example of redox reaction
– Breaks certain bonds in the hair through a reduction reaction that
adds hydrogen atoms to the hair
– Hair is reduced and the perm solution is oxidized
– Neutralizer then oxidizes the hair by removing the hydrogen atoms
that were previously added by the perm solution
– When hair is oxidized, the neutralizer is reduced
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
Oxidation is the result of either the addition of oxygen or the loss
of hydrogen
Reduction is the result of either the loss of oxygen or the
addition of hydrogen
Summary
We have learned common product
ingredients related in perming
 The importance of a pH scale
 Difference of oxidation & reduction
reactions
