Controlled radical polymerization of N-acryloylglycinamide and UCST-type phase transition of the polymers

摘要

N-Acryloylglycinamide was polymerized via the reversible addition fragmentation transfer process without sacrificing its key property, the upper critical solution temperature in water. This could be achieved by choosing an appropriate nonionic initiator[2, 2'-azobis(4-methoxy-2.4-dimethyl valeronitrile)(V-70)]and nonionic chain-transfer agent(cyanomethyl dodecyl trithiocarbonate). A good molar mass control was accomplished as proved by the linear increase of molar mass with conversion, a chain extension experiment, and low dispersity. The influence of molar mass, polymer end groups, or salt concentration on the cloud point was analyzed by turbidimetry. Polymer end groups exerted a distinct effect on the cloud points, whereas the influence increased with decreasing molar masses.