Abstract: Miscibility and mechanical properties of blends of linear low density polyethylene(LLDPE) and conventional low density polyethylene(LDPE) were studied by differencial scanning calorimetry(DSC), wide angle X-ray diffraction, dynamic mechanical analysis and static mechanical property measurements. Three endothermic peaks are evident in the DSC traces of the blends, suggesting the formation of a new partly cocrystallized phase. The dynamic mechanical relaxation behaviour of the LLDPE/LDPE blends was found to be close to both components in the vicinities of γ and β regions whereas the blends are dominated by the LLDPE component at the high temperature α regions. The improvement in mechanical properties of the blends has been attributed to the partial cocrystallization between the components in the crystalline phase and the miscibility in the amorphous phase.

Key words: DSC, WAXD, mechanical property, LLDPE, LDPE, blend, miscibility