Reversible crosslinks in cotton modified with N-hydroxymethylacetylthioacetamide

The reaction of cotton fabric with N-hydroxymethylacetylthioacetamide (HOCH₂-NHCOCH₂SCOCH₃) yields acetylthioacetamidomethylcellulose, which can be saponified under mild conditions to the corresponding thiol derivative, mercaptoacetamidomethylcellulose. Some reactions of the thiol group are discussed, including oxidation to disulfide, repeated reduction-oxidation cycles, and blocking with alkyl halides. Chemical methods were used in establishing the occurrence and extent of the predicted reactions and their dependence on specific variables in the system. Changes in the crease recovery and tensile strength of the cotton derivative obtained in the reactions were found to be qualitatively consistent with the expected structures. The results of this work show that crosslinks can be obtained reversibly in cotton by this sequence of reactions. Intervening side reactions produce a gradual decrease in the yield of the desired products, however, as the number of cycles increases. Mercaptoacetamidomethylcellulose provides a limited but useful model for the investigation of reversible crosslinks in cellulose.