Controlled Synthesis, Dye-fixing Performance and Dye-fixing Mechanisms on Cotton Fabric of Novel Reactive Cationic Copolymers of N,N-DiaIlyI-3-hydroxy-azetidinium Chloride and Dimethyldiallylammonium Chloride (P(DHAC-DMDAAC)s)

摘要

First, a series of novel reactive cationic copolymers (P(DHAC-DMDAAC)s) of N,N-diallyl-S-hydroxy-azetidmium chloride (DHAC) and dimethyldiallylammonium chloride (DMDAAC) with controlled structures and controlled molecular weights characterized by intrinsic viscosities of 0.11-0.89 dLg~(-1) were successfully synthesized by varying the molar ratios of raw materials DHAC to DMDAAC from 1:99 to 20:80 and increasing initial monomer concentrations from 35 to 55 % with a decrease of initiator amount from 7 to 3 % during polymerization. Second, it was found that the dye-fixing performance of P(DHAC-DMDAAC)s could be further increased by incorporation of 7 % molar content of DHAC units into the main chains of controlled-molecular-weight poly(dimethyldiallylammonium chloride) (PDMDAAC) dye fixatives, and their best dye-fixing performance was better than all the widely used commercial polycationic dye fixatives, indicating that the obtained P(DHAC-DMDAAC)s could be novel useful reactive polycationic dye fixatives for cotton fabric. Last, it was found from studies on dye-fixing mechanisms on cotton fabric by modern analysis techniques that the reactive units (DHAC) of the obtained P(DHAC-DMDAAC)s could form covalent bonds with the hydroxyl groups of cotton (cellulose) to give an ether linkage, resulting in strong interactions of P(DHAC-DMDAAC)s with the cotton fabric as well as the electrostatic forces between the anionic dyes and the basic cationic groups in the polymers to produce water-insoluble colour lakes, for the development of the dye fastness on cotton fabric.