Gas phase polymerization of ethylene towards UHMWPE

Abstract

For the first time, ultra-high molecular weight polyethylene (UHMWPE) was produced in gas phase processwith a new fluidized bed concept where the solids are dispersed phase and the gas is bulk phase as opposed to conventionalfluidized bed reactors (FBRs). With this concept, UHMWPE with average molecular weights about 1-6,9 × $10^6$ gmoles −1 were produced with a commercial supported Ziegler-Natta catalyst by using a gas phase mini semibatch reactorsystem. Additionally, optimum conditions of gas phase polymerization for the best results of productivity, catalystactivity, molecular weight and crystallinity were determined by Taguchi experimental design and catalyst stability at theoptimum condition was tested by video microscopy polymerization. The characterization of products was carried outexperimentally by TGA, DSC, FTIR, and NMR.