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

在不同条件下进行了含官能团的苯乙烯和1，3-丁二烯衍生物的阴离子聚合反应。在含烷基羧酸酯官能团(I)的苯乙烯阴离子聚合中，在-95℃的四氢呋喃中，以钾为反离子聚合，可形成稳定的活性聚合物。在锂反离子的情况下，没有发生聚合。通过在中性条件下用三甲基硅基碘处理，得到具有良好链结构的聚(4-乙烯基苯甲酸)，从而实现了聚合物中酯功能的定量水解。对于含烷基磺酰胺(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端物种的聚集。当在-78℃的四氢呋喃中与钠和/或钾离子对抗时，含有缩醛基团保护的1，3-丁二烯(IV)和羟基(V)的阴离子聚合导致了分子量可控的窄分子量分布的聚合物的形成。所得聚合物的微观结构主要为1，2-和3，4-，接近于在极性溶剂中制备的聚异戊二烯的结构。

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.