Polyurethane macroinitiator for controlled monomer insertion of styrene
Polyurethane macroinitiator for controlled monomer insertion of styrene
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DOI：
10.1021/ma021091i
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发表时间：
2003-03-11
期刊：
影响因子：
5.5
通讯作者：
Takahara, A
中科院分区：
文献类型：
--
作者：
Higaki, Y;Otsuka, H;Takahara, A
采用二异氰酸酯与TEMPO基二元醇加成反应制备了主链含烷氧基胺结构的聚氨酯。以TEMPO型聚氨酯为大分子引发剂，进行了苯乙烯的本体自由基聚合。GPC，NMR和IR数据表明，插入反应被精确控制，得到由聚氨酯基团和聚苯乙烯链段组成的嵌段共聚物。从模型聚合的结果，可以推断，明确定义的聚苯乙烯链插入到大分子引发剂。所得聚合物在溶剂中的溶解度与大分子引发剂和苯乙烯均聚物相比有很大的不同。在极性溶剂中的溶解度随着插入聚苯乙烯链长的增加而逐渐降低。
Polyurethane containing alkoxyamine units in the main chain were prepared by polyaddition of diisocyanate with TEMPO-based diol. Radical polymerization of styrene was carried out in bulk with TEMPO-based polyurethane as macroinitiator. GPC, NMR, and IR data revealed that the insertion reaction was accurately controlled to afford the segmented copolymers composed of both urethane groups and polystyrene segments. From the results of model polymerization, it is inferred that the well-defined polystyrene chains were inserted into the macroinitiator. The obtained polymers showed quite different solubility in solvents compared with the macroinitiator and styrene homopolymer. The solubility in polar solvents decreases gradually with increasing inserted polystyrene chain length.