Study on the characteristics and application of the temperature-sensitive N-isopropylacrylamide copolymer with methacrylate segments

A series of linear copolymers p(N-isopropylacrylamide-co-methyl methacrylate),p(N-isopropylacrylamide-co-ethyl methacrylate) and p(N-isopropylacrylamide-co-butyl methacrylate) with different mass ratio were synthesized by solution free radical polymerization method.The structures of these copolymers were characterized by infrared spectrum and TG analysis.The low critical solution temperature(LCST) of aqueous copolymers solution was measured by UV-Vis.The aqueous solution of copolymers change from transparent to opaque when the temperature is above LCST.This change was reversible and exhibited celerity,marked sensitivity and good reproducibility.The results showed that different ratio of comonomer influenced temperature sensitive properties significantly.The range of LCST can be regulated from 18-32℃ based on the mass ratio of comonomer.The transmittance of the aqueous solution nearby the LCST was tested by UV-Vis spectrophotometer and the transmittance showed significant change nearby LCST.The transmittance of aqueous solution was influenced by concentration,the quantity and sorts of comonomer when the temperature was lower than LCST.The aqueous solution is expected to be applied as a kind of intelligent light-control material.