Reaction mechanism of tetrakis hydroxymethyl phosphonium with Collagen protein

To gain an understanding of the reaction mechanism of tetrakis hydroxymethyl phosphonium chloride (THPC) and collagen protein, we examined the interactions of THPC with polycaprolactam, polyvinyl alcohol and ethylenediamine, which were used as the substitutes for the amido, hydroxyl and amino groups of collagen protein. It was found that tetrakis hydroxymethyl phosphonium mainly linked with amino groups of collagen and to a lesser extent with hydroxyl groups and amido groups. The combination capacity of tetrakis hydroxymethyl phosphonium with hydroxyl groups and amido groups changed with pH and reached a peak at pH8.0.