热敏性聚(N-乙烯基异丁酰胺)接枝高分子微球的合成

STUDY ON THERMOSENSITIVE POLY(N-VINYLISOBUTYRAMIDE) GRAFTED POLYSTYRENE NANOPARTICLES

用自由基聚合和端基反应法合成了大分子单体聚 (N 乙烯基异丁酰胺 ) (PNVIBA) ,将其与苯乙烯在乙醇 水的混合溶剂中进行分散共聚 ,得到了PNVIBA接枝聚苯乙烯 (PNVIBA g PSt)高分子微球 .用GPC、激光光散射和电子显微镜等对聚合物的分子量和微球直径及形态进行了表征 .研究结果表明 ,大分子单体PNVIBA和PNVIBA g PSt高分子微球具有明显的热敏性 ,并且发现PNVIBA g PSt微球直径和形态可通过改变反应条件加以控制 。

Poly(N-vinylisobutyramide) (PNVIBA) macromonomer was synthesized by free radical polymerization of N-vinylisobutyramide in the presence of AIBN and using p-chrolomethylstyrene as end, capping agent. The molecular weight of PNVIBA can be controlled based on the process of prepared NVIBA oligomers by changing concentration of 2-mercaptethanol The PNVIBA macromonomers exhibit remarkable thermosensitive properties for temperature change in aqueous I solution. The-PNVIBA grafted polystyrene (PNVIBA-g-PSt) polymeric nanoparticles were prepared by the free radical dispersion, copolymerization of PNVIBA macromonomer and styrene in ethanol or ethanol/water mixed solvents. The effects of molecular weight and concentration of the macromonomer and composition of solvents on the particle size and morphology of the PNVIBA-g-PSt nanoparticles were studied. Changing macromonomer concentration and reaction condition could control the particle size in diameter and morphologies of the nanoparticles.