Photo-aging changes in mechanical properties of high impact polystyrene, polystyrene-based binary and compatibilized ternary blends

In this work, the photo-aging behavior of high impact polystyrene (HIPS), polystyrene/ethylene propylene diene monomer (PS/EPDM) binary blends, and compatibilized polystyrene/ethylene propylene diene monomer/ polyamide ۶ (PS/EPDM/PA۶) ternary blends was studied and compared together. Photo-degradation of polymer blends faces considerable challenges, because a polymer blend is a compound of multiple components with particular interactions and its components may function as degrading or stabilizing agents. Photo-aging generally can cause changes in the color and mechanical properties of polymer compounds. Attenuated total reflection Fourier transform spectroscopy (ATR-FTIR) was conducted to study the chemical interactions between components in the prepared samples. The morphological structure of blends was studied by using scanning electron microscopy (SEM). The impact and tensile strength of the samples were measured and compared after exposure to UV radiation. To study the changes in the appearance, the yellowness index values of the samples were followed at different periods of exposure to UV irradiation. The post-radiation results showed similar mechanical performance of ternary and binary blends with the retention of mechanical properties close to each other. The impact strength and elongation-at-break for the HIPS sample were greatly reduced compared to the blends, showing their retention by ۸.۴۶ and ۷.۸۶%, respectively. The ultimate tensile strength retention in each sample is between ۷۰ and ۸۲% and there is no significant difference between them. The final yellowness index of HIPS was measured to be ۱.۶ and ۱.۲ times higher than that of the binary and ternary blends, respectively.

کلیدواژه ها:

Ternary blend ، photo-degradation ، photo-aging ، High Impact Polystyrene ، UV radiation