Preparation of ultrahigh molecular weight ethylene/1-octene block copolymers using ethylene pressure pulse feeding policies

Abstract

Ethylene pressure pulse feeding policies were employed in ethylene/1-octene living copolymerization with fluorinated FI-Ti catalyst. Ultrahigh molecular weight ethylene/1-octene block copolymers having hard-soft diblock structure and hard-soft-hard triblock structure were obtained. The soft blocks had high 1-octene content, while the hard blocks were mainly ethylene. The blocky structures were confirmed by NMR and high temperature GPC analyses. DSC measurements also showed that the hard blocks exhibited a high level of crystallinity and the soft blocks gave good low temperature flexibility. The block copolymers thus prepared have potential in thermoplastic elastomer applications.