双锂活性短链引发剂两步法合成SBS的研究

Study on synthesis of SBS prepared by two step addition process with dilithium initiator

以北京化工大学已取得专利的双锂活性短链为引发剂，环己烷为溶剂，四氢呋喃为极性添加剂，采用两步加料的方法合成了相对分子质量分布在１１３～１２５之间的ＳＢＳ。经核磁共振、红外光谱、差示扫描量热法对ＳＢＳ进行了表征，表明合成产物具有嵌段性质，微观结构符合热塑性弹性体的要求。用透射式电镜观察到了聚合物具有良好的微观相分离结构。力学性能测试结果表明，该产品拉伸强度可达２０ＭＰａ以上、断裂伸长率９００％以上、永久变形小于４４％，可满足一般工业化要求。

On the basis of patent of dilithium initiator, SBS with molecular weight distribution 1 13～1 25 was synthesized by two step addition process with dilithium as initiator, cyclohexane as solvent and tetrahydrofuran as polar additive. SBS was characterized by GPC, 1 H NMR, IR, DSC. The results showed that SBS is block copolymer and its microstructure is satisfactory to requirement of thermoplastic elastomer. Good two phase separation structure was observed through TEM. The mechanical properties of SBS were measured. The results show that the tensile strength is more than 20MPa; the elongation at break was more than 900% and the permanent set is less than 44%. These properties were able to meet the requirement of general industrialization.