Synthesis and characterization of polyethylene/oxidized polyethylene miscible blends and role of OPE as a viscosity control

Polymer blending allows for new materials to be designed with unique properties. Here, blends of linear low density polyethylene (PE) and oxidized polyethylene (OPE) have been prepared. PE/OPE blends are characterized for their molten state properties by thermal analysis and rheology; the solid state properties are studied by scattering, diffraction, and tensile testing. Melt miscibility was confirmed by a negative Flory-Huggins interaction parameter (χ -2.3) from Hoffman-Weeks plots. Additionally, a continuous decrease in melting temperature (from 123 to 119 °C) and thermal stability of blends (25% weight loss from 454 to 416 °C) was observed with increasing OPE loading from 0 to 50 wt %. Time-temperature master curves revealed the shifting of the glassy region to higher frequencies and formation of relaxed polymer chains in the glassy region. A plasticization effect was observed with zero shear viscosity of the blends decreasing with increasing OPE loading. Finally, a decrease in lamellar thickness of PE (from 180 to 140 Å) with increasing OPE resulted in increasing the blends' brittleness.