Synopsis

COMPARISONS were made of the EFFECTS of four REACTIVE CHEMICAL processes on HAIR and on CUTICLE and CORTEX fractions isolated after chemical processing. The processes tudied were bleaching, thioglycolate reduction, full permanent waving and alkaline relaxing. The comparisons were based on amino acid analysis, scanning electron microscopy, gel electrophoresis of extracted protein, and analysis of free sulfl•ydryl groups by alkylation with tritiated iodoacetic acid. Details of amino acid analyses of processed whole hair and of its cuticle and cortex are reported with differences hown among the several treatments. Cystine content was frequently altered by the chemical treatments and by alkali relaxing to the greatest extent of all. The radioactive tagging experiments howed that virgin hair contains an appreciable number of free sulfhydryl groups and that the treatmen. ts,except for bleaching, increase the number of such groups. The data suggest that sulfhydryl groups were about equally distributed between cuticle and cortex protein after thioglycolate reduction and complete permanent waving. More sulfhydryl was found in cuticle than in cortex, in bleached and in untreated hair. Alkaline relaxation resulted in greater production of-SH groups in cortex than cuticle. SEM shows the surface morphology to be not seriously altered by the chemical treatments tudied. Upo