Preparation of poly(butylene terephthalate)/oxazoline containing polystyrene graft copolymer through melt-blending and their application as a compatibilizer in polycarbonate/polystyrene blend

The polybutylene terephthalate (PBT)/oxazoline containing polystyrene (RPS) graft copolymer was prepared through melt reaction of PBT and RPS. The formation of the PBT/RPS graft copolymer was noticed by the increase in torque during melt blending in a Haake Buchler internal mixer and also confirmed by the observation of Fourier transform infrared spectroscopy (FT-IR) after the extraction of RPS from the PBT/RPS mixture. The compatibilized polycarbonate (PC)/polystyrene (PS) blends with the pre-made PBT/RPS graft copolymer were prepared by melt blending in the internal mixer. The morphologies of these blends were examined by the transmission electron microscope (TEM). The compatibilized PC/PS blends showed finer morphologies than the uncompatibilized blend. Tensile properties of these blends were also investigated.