Synthesis of new 1-decene-based LLDPE resins and comparison with the corresponding 1-octene- and 1-hexene-based LLDPE resins

This article extends the composition of linear low-density polyethylene (LLDPE) resins to that containing 1-decene comonomer units, and examines the effects of comonomer (type and concentration) to copolymerization and physical properties of LLDPE resins. CGC metallocene technology, under high temperature and high pressure (industrial reaction condition), was used to prepare three types of well-defined LLDPE copolymers containing 1-hexene, 1-octene, and 1-decene units. They show high molecular weight with narrow molecular weight and composition distributions, comparative catalyst activities, and similar comonomer effects. However, 1-decene seems to exhibit significantly higher comonomer incorporation than 1-hexene and 1-octene, which may be associated with its high boiling point, maintaining liquid phase during the polymerization. The resulting LLDPE copolymers show a clear structure-property relationship. Melting temperature and crystallinity of the copolymer are governed by mole % of comonomer. The increase of branch density linearly decreases the LLDPE melting point and exponential reduction of its crystallinity. On the other hand, the density of the copolymer decreases with the increase of comonomer weight %, which shows a sharp linear relationship in the low comonomer content. The tensile properties of I-decene-based LLDPE are very comparative with those of the commercial LLDPE resins with similar compositions. (c) 2006 Wiley Periodicals, Inc.