Influence of chlorinated polyethylene on poly (vinyl chloride)/poly (alpha-methylstyrene-acrylonitrile) blends: Mechanical properties, morphology and thermal properties

The influence of chlorinated polyethylene (CPE) content on properties of poly (vinyl chloride) (PVC)/poly (alpha-methylstyrene-acrylonitrile) (alpha-MSAN) blends (70/30) was investigated. Addition of CPE contributed to improvement in toughness but played a negative role in strength and modulus. With the addition of 15 phr CPE, the impact strength increased by nearly four-fold compared with that of pure PVC/alpha-MSAN. A transition of mechanical properties was observed in the range of 5-8 phr CPE. The morphology observed by scanning electron microscopy was heterogeneous and correlated well with the mechanical properties. Thermogravimetric analysis revealed improvement in thermal stability. Glass transition temperature measured by differential scanning calorimetry and dynamic mechanical thermal analysis was constant, as corresponded with PVC/alpha-MSAN matrix, indicating the immiscibility of the ternary blends. Heat distortion temperature remained almost unchanged over all the compositions. Our study showed that addition of CPE enhanced the toughness and thermal stability without sacrificing heat resistance of the blends. (C) 2010 Elsevier Ltd. All rights reserved.