Miscibility of poly(vinyl chloride)/ethylene‐acrylic rubber blends

The compatibility behaviour of blends of poly(vinyl chloride) with an ethyleneacrylic rubber was investigated at five compositions. Phase‐contrast microscopy revealed submicron heterogeneities at intermediate compositions, however, on the basis of the dynamic mechanical properties, one concludes that the pair is miscible at the segmental level, throughout the composition range. These properties were studied between 143 and 383 K at 110 Hz. Tensile properties are characteristic of a miscible system and modulus enhancement supports the view that synergistic effects are present. Models proposed for miscible systems accurately predict the compositional variation of T g . Also, mechanic models suitable for two‐phase systems, fail to predict the modulus dependence on composition. Fire retardancy becomes considerable already at intermediate levels of PVC.