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Alkaline or Acid. You will learn the differences in alkaline and acid perms & chemistry of perms. Chemistry of Permanent Waving. Alkaline perm solutions softens & swells the hair Raises the cuticle & permits the solution to penetrate into the cortex
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Alkaline or Acid You will learn the differences in alkaline and acid perms & chemistry of perms
Chemistry of Permanent Waving • Alkaline perm solutions softens & swells the hair • Raises the cuticle & permits the solution to penetrate into the cortex • Once in the cortex, the solution breaks the disulfide bonds through a chemical reaction called reduction • Involves either the addition of hydrogen or the removal of oxygen • Reduction reaction • Disulfide bond joins a sulfur atom on one polypeptide chain with a second sulfur atom on a neighboring polypeptide chain • Perm solution breaks a disulfide bond by adding a hydrogen atom to each of the sulfur atoms in the disulfide bond • Sulfur atoms attach to the hydrogen from the perm solution, breaking their attachment to each other • Once the disulfide bond is broken, the polypeptide chains are able to slip into their new curled shape
Chemistry of Permanent Waving • Reducing agents • Thiol compounds • Commonly referred to simply as thio / thioglycolic acid • Colorless liquid / strong unpleasant odor • Provides the hydrogen that causes the reduction reaction in perm solutions • Strength is determined by the concentration of thio • Stronger perms have a higher concentration of thio w/ a greater number of hydrogen atoms • More hydrogen atoms are available, more disulfide bonds are broken
Chemistry of Permanent Waving • Thioglycolic acid • Acid, do not swell the hair or penetrate into the cortex • Manufacturers add an alkalizing agent • Ammonia is added and produces a new chemical called ammonium thioglycolate, which is alkaline • ATG is main active ingredient or reducing agent in alkaline perms • Degree of alkalinity (pH) • Second factor in overall strength of perm solution • pH ( alkalinity ) of the perm solution should correspond to the resistance, strength, and porosity of the cuticle layer
Exothermic Waves • Produces heat • Creates an exothermic chemical reaction that heats up the solution & speeds up the processing • Activator is added immediately before use, which causes the increase in perm solution • The increase in temperature causes a chemical reaction, which shortens the processing time • 3 components: • Solution – ( reductiton ) • Activator • Neutralizer ( rebonding ) • Solution contains thio, just as in a cold wave • Activator contains oxidizing agent, usually hydrogen peroxide • Neutralizer contains hydrogen peroxide, lanolin & other special ingredients • Stops the action of the perm and hardens the hair to its new form • Acid solution
Endothermic waves & Ammonia-free waves • Endothermic waves • Absorbs heat from its surroundings • Activated by an outside heat source • Hood-type dryer • Will not process properly at room temperature • Most true acid waves are endothermic & require heat of a hair dryer • Ammonia-free waves • Examples of alkanolamines as a substitute for ammonia • Aminomethylpropanol (AMP) • Monoethanolamine (MEA) • Do not smell as strong • Alkaline & just as damaging
Thio-free & low –pH waves • Thio-free waves • Other ingredients than ATG • Reducing agent • Cysteamine • Mercaptamine • These thio substitutes are not technically ATG • Can be just as damaging as thio perms • Low-pH waves • Sulfates, sulfites & bisulfites • Low pH • Not very popular • Very weak & do not provide a firm curl • Marketed as body waves or alternative waves
Summary • A variety of permanent waves are available in salons today • Depending on hair texture, density and porosity determines which perm to use; acid or alkaline