Thermal analysis of single-site polymers in binary blends of low-molecular-weight linear polyethylene and high-molecular-weight branched polyethylene

摘要

The cocrystallization phenomenon has been studied by blending a low-molecular-weight linear polyethylene (LPE) with a high-molecular-weight lightly branched ethylene-hexene copolymer, as a function of blend composition and cooling rate. The materials are based on single-site catalysts. Differential scanning calorimetry indicates that the upper limit on the degree of branches for cocrystallization with LPE is lower than observed in blends with Ziegler-Natta based materials, in accordance with results obtained by other authors on different single-site blend systems. The effect of the cooling rate on blends with low LPE content is probed, and the observed behaviour is discussed in light of earlier observations on similar blends. (C) 2000 Elsevier Science B.V. All rights reserved. [References: 27]