原位核磁共振技术研究丙烯聚合N催化剂制备过程中环氧氯丙烷的化学反应

摘要

利用原位NMR技术，通过在超声清洗器内超声并加热来模拟实验室的机械搅拌条件，对丙烯聚合N催化剂制备过程中环氧氯丙烷（ECP）所发生的化学反应进行了研究，跟踪表征了不同时刻反应体系的1H NMR谱图和31P NMR谱图，计算出不同反应时刻的ECP转化率，并对体系内的络合情况进行了初步探讨。1H NMR表征结果显示，在N催化剂的制备过程中， MgCl2-ECP-磷酸三丁酯（TBP）体系中ECP发生了化学反应，归属于ECP的H谱峰消失，生成了只有两处H化学位移的新物质ECP·MgCl2；计算结果表明，在反应时间为130 min时，ECP转化率达到90.28%；31P NMR的表征结果显示，TBP与反应产物ECP·MgCl2有更强的络合作用，原有的MgCl2·TBP络合体系解离并生成新的络合物ECP·MgCl2·TBP，导致P的化学位移向高场方向移动。%The chemical reaction of epichlorohydrin(ECP)in the preparation of N-catalyst for propylene polymerization was studied in an ultrasonic cleaner with ultrasonic wave instead of mechanical stirrer by means of in situ NMR technique. The results showed that,there was chemical reaction in the MgCl2-ECP-tributyl phosphate(TBP)system,the1H NMR peak of ECP disappeared and a new product ECP-MgCl2 with only two1H NMR chemical shifts was generated. The chemical reaction was investigated by means of1H NMR and31P NMR in different reaction time. The conversion of ECP in the reaction was obtained by integral area ratio of1H NMR,which reached 90.28% in 130 min. The results of31P NMR indicated that there was strong complexation between TBP and the reaction product(ECP·MgCl2)which led to the disassociation of MgCl2·TBP,the formation of a new complex ECP·MgCl2·TBP,and the movement of the P chemical shift to high field.