摘要
以SN-1催化剂进行乙烯常压聚合动力学研究表明,催化剂高效的主要原因是活性中心浓度明显增大、表观活化能△E较低。研究了ZnCl_2对乙烯聚合反应的影响。发现ZnCl_2能有效地降低聚乙烯的分子量,并能显著地提高催化效率,当ZnCl_2浓度过大时,则对聚合反应有抑制作用。
The kinetics of the polymerization of ethylene has been studied at normal pressure with the highly active catalyst system TiCl4,NdCl3/MgCl2/Al(C2H5)3. The rate of polymerization VP,the specific number of active centers [C*] , the propagation rate constant kP,the activation energy ΔE and the lifetime of growing chain L were obtained by a kinetics method for the polymerization of ethylene. The influence of ZnCl2 on the polymerization of ethylene has been investigated. It has been found that ZnCl2 is a considerably effective transfer agent. Not only it decreases the molecular weight of polyethylene, but raises the catalytic efficiency notably as well. However, at a higher ZnCl2 concentration, the rate of polymerization was decreased.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
1990年第2期193-196,共4页
Chemical Journal of Chinese Universities
