Development of nanopowder additive polyphenylene sulfide composites with high thermal conductivity and investigation of their thermal and mechanical properties

In this study, the mechanical and thermal properties of polyphenylene sulfide (PPS) matrix composites were improved by using different additives and their ratios. Graphene (GR), carbon fiber (CF), and hexagonal boron nitride (h-BN) were used as additives, and the composites were produced using a twin-screw extruder. First, test specimens were produced to investigate the mechanical properties of pure PPS and the composites with additives, and tensile and 3-point bending tests were conducted. The results indicated that polymer additives improved mechanical properties but reduced stiffness at higher additive ratios. TGA and DSC analyses were performed to determine thermal stability. From the TGA analyses, it was concluded that the composites with additives showed a slower degradation compared to pure PPS, that weight loss decreased with increasing additive ratios, and that, accordingly, thermal stability was higher in the 10% GR/PPS, 10% CF/PPS, and 20% h- BN/PPS samples. DSC analyses showed that low and medium levels of additives increased crystallinity, while high levels decreased it due to restriction of chain mobility. At the same time, the additives' increased glass transition temperature (Tg) also indicated that the material became more resistant to high temperatures. Finally, thermal conductivity analyses were performed using a thermal camera, and the results were compared using heat mapping. It was concluded that the 20% h-BN- added PPS composite provided the highest thermal conductivity compared to the other additive samples.