Study on the Effect of Mold Temperature on The Mechanical and Thermal Properties of Recycled Polyphenylene Sulfide

Polyphenylene sulfide (PPS) is a high-performance thermoplastic commonly employed in aerospace components due to its outstanding strength, heat tolerance, and resistance to chemicals. However, as the use of PPS materials continues to grow, so does the volume of resulting waste, raising concerns about long-term sustainability. Therefore, the integration of PPS recycling methods requires systematic investigations. This study examined the effect of mold temperature during hot-press forming process on the mechanical and thermal properties of the recycled PPS. The experiment focused on the behavior of recycled PPS at various temperatures, ranging from 180 °C to 220°C. Mechanical properties of the recycled PPS at the optimized temperature were evaluated through tensile, flexural and impact tests, while thermal properties were evaluated through differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The findings show that raising the mold temperature (Tm) enhances interfacial adhesion between the matrix and the carbon fibers (CF), which also improves the composite’s thermal stability. At a Tm of 200 °C, the recycled PPS exhibits its optimal thermal, and mechanical performance, achieving a tensile strength of 549.92 MPa, flexural strength of 821.10 MPa, impact strength of 100.18 J/m, and the highest degree of crystallinity of 25.03%. Overall, this work highlights how mold temperature influenced key properties of recycled PPS and provided useful guidance for processing such materials in aerospace and other engineering fields.