苯乙烯-环氧丙烷多嵌段共聚物的合成及表征

Synthesis and characterization of multiblock copolymers of styrene and propylene oxide

在端双羟基聚苯乙烯和聚丙二醇中加入偶联剂 2 ,4-甲苯二异氰酸酯 (TDI) ,采用一步法或二步法制备了苯乙烯 -环氧丙烷多嵌段共聚物。结果表明 ,由二步法制备的共聚物较一步法制备共聚物中均聚物的含量少。粗产物可分别用乙醇及十氢萘萃取 ,以除去未反应的聚丙二醇及端双羟基聚苯乙烯。纯化物经红外光谱法、核磁共振波谱法、凝胶渗透色谱法、膜渗透压法和元素分析法测试表明 ,试样为聚苯乙烯与聚环氧丙烷的多嵌段共聚物。

Styrene and propylene oxide multiblock copolymers were synthesized by coupling between polypropylene glycol and dihydroxy-terminated polystyrene with 2,4-toluene diisocyanate(TDI) as the coupling agent via one step method or two step method. The results showed that it was better to use two step method.The copolymer obtained by two step method possesses less homopolymers than that of obtained by one step method. The crude products could be purified by extractions with ethyl alcohol and decalin to remove the unreacted polypropylene glycol and dihydroxy-terminated polystyrene, respectively. The purified products were characterized by infrared spectroscopy, nuclear magnetic resonance spectroscopy, gel permeation chromatography, membrane osmometry, elemental analysis, and shown to be multiblock copolymers of polystyrene and polypropylene oxide.