Comparative study on tensile properties and microstructure development in elastomer‐modified cyclic olefin copolymer

Mechanical and morphological properties of blends of cyclic olefin copolymer (COC) with polyolefin‐octane copolymer (POE) and polyethylene‐vinyl acetate (EVA), as the second phase, are thoroughly discussed over full composition range. Scanning electron microscopy revealed that both the systems are immiscible pairs showing biphasic morphology; however, co‐continuity was seen upon varying composition. The mechanical characteristics, tensile modulus, yield strength, tensile strength, and elongation at break were evaluated varying blend composition. It was found that addition of POE to COC results in a higher decrease in tensile modulus when compared to COC/EVA pair. Mechanical results were correlated with several theoretical models and the best model for estimating tensile modulus was determined. Among examined models, the best fitting to experimental data for both series of the blends was provided by the Lyngaae‐Jorgensen model. J. VINYL ADDIT. TECHNOL., 22:222–230, 2016. © 2014 Society of Plastics Engineers