【摘要】 将蒙脱土 (MMT)负载的聚合催化剂rac Et(Ind) 2 ZrCl2 和均相低聚催化剂 { [(2 ArNC(Me) ) 2 C5H3N]FeCl2 } (Ar=2 ,4 C6 H4 (Me) 2 )组成双功能催化体系用于乙烯原位共聚制备线性低密度聚乙烯 (LLDPE) .通过调节两种催化剂之间的比例和MAO的用量制备了一系列支化度不同的LLDPE产品 .聚合反应动力学曲线表明 ,两种催化剂表现出各自的乙烯吸收特征 ,蒙脱土负载化的共聚催化剂催化乙烯聚合时反应平稳易控制 .DSC曲线表明 ,聚合物的熔点和结晶度随Fe Zr的增大而减小 .用密度梯度法测得的聚合物密度随Fe Zr的增大而降低 .从1 3C NMR谱图上可以看到 ,得到的聚合物是LLDPE ,其支化度随Fe Zr的增大而增大 ,聚合物中仍含有未共聚的α 烯烃 ,这一点从GPC上也能得到验证 .扫描电镜 (SEM)照片表明用这种双功能催化剂共聚得到的LLDPE具有良好的形态更多还原

【Abstract】 Linear low-density polyethylene (LLDPE) has been prepared by in situ copolymerization of ethylene with a dual functional catalyst,which was composed of rac-Et(Ind) 2ZrCl 2 supported on montmorillonite (MMT) and {[(2-ArNC(Me)) 2C 5H 3N]FeCl 2}(Ar=2,4-C 6H 4(Me) 2) oligomerization catalyst.A series of LLDPE with different branching degrees were obtained by adjusting the molar ratio of Fe and Zr (Fe/Zr),the molar ratio of Al and (Fe+Zr) (Al/(Fe+Zr)) as well.The kinetics curves of polymerization show that the two catalysts exhibit respective catalytic characterizations,and the activity of copolymerization catalyst is more smoothly after supported on MMT.As increasing the Fe/Zr ratio,the densities of polymers measured by density gradient method and the melting points of polymers obtained from DSC decrease. 13C-NMR shows that the polymers are LLDPE,and their branching degrees increase as the increasing of the Fe/Zr ratio.At the same time,there are some unreacted α-olefins in polymers,which were confirmed by 13C-NMR and GPC.The SEM shows that the polymerization catalyst supported on MMT may produce LLDPE with better morphology than that produced by the catalyst in homogeneous.更多还原