Effect of Cooling Temperature on Crystalline Behavior of Polyphenylene Sulfide/Glass Fiber Composites

Poly (phenylene sulfide) (PPS) is a super engineering plastic that has not only excellent rigidity and high chemical resistance but also excellent electrical insulation properties; therefore, it can be applied as an electronic cover or an overheating prevention component. This plastic has been extensively applied in the manufacture of capacitor housing as, in addition to being a functional and lightweight material, it has a safety feature that can block the electrical connection between the electrolyte inside and outside the capacitor. Moreover, the fabrication of PPS composites with high glass fiber (GF) content facilitates the development of lightweight and excellent future materials, which widens the scope of the application of this polymer. However, the crystallinity and mechanical properties of PPS/GF composites have been found to vary depending on the cooling temperature. Although extensive studies have been conducted on the influence of cooling temperature on the crystalline behavior of PPS-based composites, there has been limited research focused particularly on PPS/GF composites for capacitor housing applications. In this study, to apply PPS/GF composites as film capacitor housings, specimens were prepared via injection molding at different cooling temperatures to investigate the composites' tensile, flexural, and impact energy absorption properties resulting in increases in mechanical properties at high cooling mold temperature. Fracture surface analysis was also performed on the fractured specimens after the impact test to confirm the orientation of the GF and the shape of the micropores. Finally, the crystallinity of the composites increased with higher cooling temperatures due to the extended crystallization time.