The effects of molecular parameters on the low-temperature toughness of pe-pe blends.

摘要

Polyethylenes, as a series of polymers, display a wide range of mechanical behavior. To investigate the molecular origin of this wide variation in mechanical behavior, particularly toughness, three series of blends were examined: low density polyethylene/high density polyethylene, linear low density polyethylene/high density polyethylene, and ultra low density polyethylene/high density polyethylene. The thermal behavior of the blends was examined by both DSC and DMTA. Although the DMTA results revealed no change in relaxation behavior with blend type or thermal history, the DSC results revealed significant modification of the crystallization process of the blends compared to the homopolymers. Changes in mechanical behavior, at both room and sub-ambient temperatures, were correlated to these morphological modifications.