ETHYLENE POLYMERIZATION OVER CELLULOSE-SUPPORTED MODIFIED METHYLALUMINOXANE/ZIRCONOCENE CATALYST

Abstract

Presently, the polyethylene has been profusely applied in the several industries, for instance manufacturing of pipe, film and plastic bags. In polyethylene production, there are two catalysts which are used in production, including Ziegler-Natta catalyst and metallocene catalyst. The metallocene catalyst is immobilized by support and activated by cocatalyst. For the support of metallocene catalysts, both of inorganic and organic supports are applied and in this research study, cellulose which is organic support for metallocene catalyst, was used. Since, cellulose is extensively used biopolymer representing a great deal of total annual biomass production. Due to environmental issues, natural materials have been widely used instead of synthetic material. However, cellulose, which has played the role as a support for catalytic application is not well explored. In this present study, several types of cellulose were used as support for metallocene catalyst by varying cellulose from different biomass, including bacteria cellulose. All types of cellulose were calcined under vacuum at 150oC for 4 h, and then the cocatalyst (modified methylaluminoxane, MMAO) was ex situ immobilized on these various supports. Polyethylene was synthesized by in situ polymerization using zirconocene/MMAO catalytic system. These cellulose-supported catalysts were compared with the commercial microcrystalline cellulose (MCC) supported catalyst in terms of yield and catalytic activity. It was found that the addition of cellulose as a support for metallocene/MMAO catalyst for in situ ethylene polymerization tended to increase crystallinity when compared with homogeneous catalytic system.