Well-defined polystyrene grafted to polypropylene backbone by living radical polymerization with TEMPO
Well-defined polystyrene grafted to polypropylene backbone by living radical polymerization with TEMPO
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DOI：
10.1021/ma001449f
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发表时间：
2001-02
期刊：
影响因子：
5.5
通讯作者：
Y. Miwa;Katsuhiro Yamamoto;M. Sakaguchi;S. Shimada
中科院分区：
文献类型：
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作者：
Y. Miwa;Katsuhiro Yamamoto;M. Sakaguchi;S. Shimada
采用稳定的自由基聚合技术(2，2，6，6-四甲基哌啶-1-氧基，TEMPO)研究了苯乙烯(St)与聚丙烯(PP)的接枝聚合。用空气中γ辐射(7.2kGy12和35kGy3种剂量)产生的PP过氧物作为大分子引发剂进行接枝。采用三氟乙酸法将接枝聚苯乙烯(PS)从PP主链上解离出来。用凝胶渗透色谱(GPC)测定了PS接枝和游离(未接枝)聚苯乙烯(PS Free)的相对分子质量(Mn)和多分散性。这些PS具有几乎相同的MN(接近理论MN)和窄的多分散性。在添加St单体的情况下，通过顺序激活休眠链端，将端氮化PS接枝到PP上，从而实现扩链。扩展后的PS接枝物的多分散性仍然很窄。利用该技术还合成了PP与St和甲基丙烯酸丁酯的可控无规接枝共聚物。
A stable free radical (2,2,6,6-tertamethylpiperidinyl-1-oxy, TEMPO) polymerization technique was applied to a graft polymerization of styrene (ST) to polypropylene (PP). PP peroxides produced by γ-irradiation (7.2, 12, and 35 kGy) in air were used as macromolecular initiators for grafting. Grafted polystyrene (PSgraft) was cleaved from the main PP chain by reaction with trifluoroacetic acid. The molecular weight (Mn) and polydispersity of the PSgraft and the free (nongrafted) polystyrene (PSfree) were determined by GPC. These PS's have almost the same Mn (nearly theoretical Mn) and narrow polydispersity. Nitroxide-terminated PS grafted to the PP was chain extended by sequential activation of the dormant chain ends in the presence of additional ST monomer. The polydispersity of the extended PSgraft remained narrow. A controlled random graft copolymer of PP with ST and n-butyl methacrylate was also synthesized using this technique.