Synthesis of thermoresponsive N-isopropylacrylamide–N-hydroxymethyl acrylamide hydrogels by redox polymerization

In this study, a random copolymer of N-isopropylacrylamide and N-hydroxymethyl acrylamide [poly(NIPAM-co-NHMAAm)], having a thermoresponsive character was prepared by a redox copolymerization method. Poly(ethylene glycol), PEG 4000, was used to increase the thermoresponsitivity of the resultant copolymeric structures. NIPAM-co-NHMAAm copolymers with different thermoresponsive properties were obtained by changing the initial NIPAM/NHMAAm mole ratio, total monomer, PEG 4000, and N,N′-methylenebisacrylamide, (MBAAm), concentrations.