Structure, thermal characterization and mechanical properties of poly(phenylene oxide) and high impact polystyrene blend

The structures and thermal and mechanical properties of poly(phenylene oxide) (PPO) blends with high impact polystyrene (HIPS) were investigated. Two types of PPO were used: commercial one and the other prepared in Industrial Chemistry Research Institute (ICRI) in large laboratory scale process of oxidative polycondensation of 2,6-dimethylphenol, in the presence of complex of copper(II) bromide with morpholine as acatalyst (PPO-IChP). It has been proved that PPO/HIPS blends are miscible in amorphic state, independently on PPO type, because they show the single glass transition temperature, determined by differential scanning calorimetry (DSC) and dynamic­ mechanical thermal analysis (DMTA). Homogeneity of the blends was confirmed by scanning electron microscope (SEM) method. The PPO-IChP/HIPS blend showed significantly higher impact strength and relative elongation at break than PPO-h/HIPS one. The type of PPO used did not influence alot heat distortion heat deflection temperature (HDT) as well as tensile or flexural strength of the blends investigated. PPO-IChP and PPO-IChP/HIPS blend showed aslightly better thermal stability than PPO-h and PPO-h/HIPS blend.