Rheological and mechanical properties in polyethylene blends

Melt rheology and mechanical properties in linear low density polyethylene (LLDPE)/low density polyethylene (LDPE), LLDPE/high density polyethylene (H DPE), and HDPE/LDPE blends were investigated. All three blends were miscibl e in the melt, but the LLDPE/LDPE and HDPE/LDPE blends exhibited two crysta llization and melting temperatures, indicating that those blends phase sepa rated upon cooling from the melt. The melt strength of the blends increased with increasing molecular weight of the LDPE that was used. The mechanical properties of the LLDPE/LDPE blend were higher than calculated from a simp le rule of mixtures, while those of the LLDPE/HDPE blend conformed to the r ule of mixtures, but the properties of HDPE/LDPE were less than the rule of mixtures prediction.