RHEOLOGICAL AND THERMAL-PROPERTIES OF BLENDS OF LOW-DENSITY POLYETHYLENE AND ITS IONOMERS

Melt rheology and DSC studies of blends of two ionomers' ethylene-acry lic acid copolymers are reported, EAA (4.6 mole % AA) and EAA (6.5), a s a function of their concentration and counter ion types with their p recursor, a low-density polyethylene. Various isothermal dynamic measu rements in the frequency range of 0.01 to 10 rad/sec, from 120 to 200 degrees C, were made; and partial master curves of G' and G'' were gen erated. Although the melts appeared to follow the conventional superpo sition principle, the Cole-Cole plots were found to be unsatisfactory in describing the miscibility of such blends. The analysis based on th e calculations of activation energies and other supporting measurement s such as Vicat softening and DSC thermal analysis indicate that such blends are immiscible and perhaps do not have LCST. The blends failed to follow the additivity rule. The Vicat softening measurements indica ted variations in the morphology of blends. The DSC studies performed on various 50/50 blends clearly demonstrated phase immiscibility.