Synthesis of Functional Polymers with Well-defined Chain Structure by Means of Anionic Living Polymerization

在不同条件下进行了苯乙烯和含官能团的1,3-丁二烯衍生物的阴离子聚合。在含烷基羧酸官能团苯乙烯(I)的阴离子聚合中，以钾作反离子，在-95℃的THF中聚合，形成稳定的活聚合物。在锂反离子的情况下，没有发生聚合。用三甲基硅基碘化物在中性条件下对所得聚合物中的酯功能进行了定量水解，得到链结构明确的聚4-乙烯基苯甲酸。对于含有烷基磺酰胺（II）和烷基磺酸盐（III）基团的单体，无论使用何种反离子，都可以定量地获得分子量分布较窄的聚合物。在某些情况下，在聚合过程中观察到聚合物的沉淀。这可能是由于活性链末端物种的聚集。含甲酰基（IV）和羟基(V)的1,3-丁二烯在-78℃的THF中与钠和/或钾离子进行阴离子聚合，得到了分子量控制、分子量分布窄的聚合物。所得聚合物的微观结构以1,2-和3,4-为主，与极性溶剂制备的聚异戊二烯结构接近。

Anionic polymerizations of styrene and 1,3-butadiene derivatives containing functional groups were carried out under various conditions. In the anionic polymerization of styrene containing alkyl carboxylate function (I), stable living polymer was formed when it was polymerized in THF at -95 C with potassium as a counterion. In the case of lithium counterion, no polymerization took place. The quantitative hydrolysis of ester function in the resulting polymer was achieved by the treatment with trimethylsilyl iodide under neutral condition to give poly(4-vinylbezoic acid) having well-defined chain structure. With monomers bearing alkyl sulfonamide (II) and alkyl sulfonate (III) groups, polymers with narrow molecular weight distributions were obtained quantitatively regardless of the counterion used. In some cases, precipitation of polymers were observed during the course of polymerization. This was presumably due to the aggregation of active chainend species.The anionic polymerizations of 1,3-butadiene containing formyl (IV) and hydroxy (V) groups protected with acetal functions resulted in the formation of polymers of controlled molecular weights with narrow molecular weight distributions when they were prepared in THF at -78 C with sodium and/or potassium counterion. The microstructure of the resulting polymers were mainly 1,2- and 3,4-, which was close to the structures of polyisoprene prepared in polar solvent.