Preparation And Properties Of Multiresponsive Block Copolymer

The strategy for synthesis of ABC type triblock copolymers via a combination of "click chemistry" and atom transfer radical polymerization(ATRP) was used,and a range of well-defined and relatively low polydispersity(PDI<1.3) macromonomers:Poly(N-isopropylacryl-amide)-block-poly(tert-butyl methacrylate)-block-poly[6-(4-methoxy-4'-oxy-azobenzene)-hexyl methacrylate](PNIPAM-PtBMA-PMMAZO)were successfully prepared by this method.Through selective hydrolysis of PtBMA yielding poly(methacrylic acid)(PMAA), water-solution triblock copolymers of PNIPAM-b-PMAA-b-PMMAZO were obtained.The obtained polymers were characterized by FT-IR,1H NMR,GPC and UV-Vis measurements. As a result,PNIPAM-b-PMAA-b-PMMAZO are solution in aqueous solution and show a responsive behavior to temperature(LCST),pH and UV light illumination.The LCST of PNIPAM-b-PMAA-b-PMMAZO aqueous solution was about 43℃,pH=5-6 in the range of the phase transition;by UV light(λ=365nm) irradiation,UV-visible spectra of the solution in the 360nm and 460nm at obvious absorption change.