Effect of the morphology of reactor powders on the structure and mechanical behavior of drawn ultra-high molecular weight polyethylenes

Abstract

Evolution of the straighten-chain-segment length distributions in three polyethylene reactor powders manufactured using different catalysts has been traced through the melting-drawing procedures carried out under the same temperature-deformation conditions. The powders exhibiting the presence of either folded or chain-extended crystalline entities yielded the oriented samples with quantitatively different interfibrillar structure, and, respectively, with different mechanical behavior concluded from their stress-strain curves and variation of the tangential modulus. The correlation between original and final properties of samples derived from reactor powders evidences a persistence of a kind of memory. The longitudinal disorder in nascent chain-extended crystals transforms virtually to the lateral disorder in the axially oriented interfibrillar material. (C) 2003 Elsevier Science Ltd. All rights reserved.