Isothermal crystallization of high density polyethylene with monomodal and bimodal molar mass distribution

Abstract

The isothermal crystallization behavior of two different high density polyethylene grades with monomodal and bimodal molar mass distribution was investigated by means of differential scanning calorimetry. The results indicate that extensive cocrystallization between linear short chains and long chains with short branches in bimodal polyethylene grade occurred. In contrast, polymer chains of different lengths in monomodal polyethylene exhibit different tendency to crystallize. This finding was explained qualitatively based on a general discussion of the effect of molar mass and branch content/length on crystallization tendency of polymeric chains.