Interaction between Polyethylenimine and Human Hair.

An irreversible penetration of [14C] polyethylenimine into a human hair was demonstrated by radioactive-tracer technique. Under ambient conditions, 1% of the imine diffused into the hair in an hour. Desoprtion of the imine was rather slow; most of the imine could not be washed out by an untagged imine solution in 24 hr indicating a possible strong interaction between the imine and the hair. The results are assumed to be applicable to the untagged imine. The swelling rate of hair in distilled water and the swelling behavior of hair in the imine were studied by light micro scopic observation. When dry hair was wetted with deionized water, a 36 ± 7% swelling was found in 24 hr. The degree of hair swelling by the imine was much greater at pH 7 than at higher pH.The effect of pH, concentration, and temperature on the swelling of the hair in the imine and some aspects of the permanent-waving mechanism by using the imine have been postulated and discussed. [ABSTRACT FROM PUBLISHER]