Mechanical and thermal properties of (acrylonitrile-styrene-acrylic)/(α-methylstyrene-acrylonitrile) binary blends

In this work, (acrylonitrile-styrene-acrylic)/(α-methylstyrene-acrylonitrile) copolymer (ASA/α-MSAN) binary alloy was prepared with different composition ratios via melt blending. This work mainly focused on improving the heat resistance of ASA. According to the results of dynamic mechanical thermal analysis, the binary blends exhibited three glass transition temperatures (T_gs) and the shift of the T_gs indicated the partial miscibility of binary blends. This partial miscibility maintained the high T_g of α-MSAN, which led to the outstanding heat resistance of binary blends. Furthermore, heat distortion temperature also showed that the heat resistance of binary blends was significantly enhanced with the addition of α-MSAN. However, the introduction of this highly rigid polymer also brought with it the sharp decrease of the impact strength and elongation at break, which is reflected in the morphologies of the blend system obtained via scanning electron microscopy. In addition, the incorporation of α-MSAN increased the tensile strength, flexural strength, and modulus. There were no new groups observed from Fourier-transform infrared spectra, which means no strong specific intermolecular interactions existed between ASA and α-MSAN. Moreover, the processibility of the blend system was obviously improved from the results of melt flow rate. J. VINYL ADDIT. TECHNOL., 22:156-162, 2016.