Poly (vinyl chloride)/poly (α -methylstyrene-acrylonitrile)/acrylic resin ternary blends with enhanced toughness and heat resistance

Abstract

In this study, tough and high heat-resistant poly (vinyl chloride) (PVC)/poly (α-methylstyrene–acrylonitrile) (α-MSAN) blends (70/30) containing acrylic resin (ACR) as a toughening modifier was prepared. With the addition of ACR, heat distortion temperature increased slightly, which corresponded with the increase in glass transition temperature measured by differential scanning calorimetry and dynamic mechanical thermal analysis. Thermogravimetric analysis showed that addition of ACR improved the thermal stability. With regard to mechanical properties, tough behavior was observed combined with the decrease in tensile strength and flexural strength. A brittle-ductile transition (BDT) in impact strength was found when ACR content increased from 8 to 10 phr. The impact strength was increased by 34.8 times with the addition of 15 phr ACR. The morphology correlated well with BDT in impact strength. It was also suggested from the morphology that microvoids and shear yielding were the major toughening mechanisms for the ternary blends. Our present study offers insight on the modification of PVC, since combination of α-MSAN and ACR improves the toughness and heat resistance of pure PVC simultaneously. Copyright © 2011 John Wiley & Sons, Ltd.