Effective flow modifiers for high-filled poly(phenylene sulfide) composites based on chemical structure similarity

Polyphenylene sulfide (PPS) is one of the representative engineering plastics used for various applications in the automobile industry. In actual applications, fiber-reinforced polymers (FRPs) are used to ensure the enhanced performance of engineering plastics. However, during processing, high-filled polymer composites suffer from high viscosity and poor dispersion. In this study, we propose a method for reducing the melt viscosity of PPS composites. We synthesized a novel flow modifier using multicomponent polymerization (MCP) to achieve effective processability and superior compatibility with PPS. The prepared flow modifier, poly-hexylbenzothioamide (PHBTA), exhibits enhanced compatibility with PPS due to similarities in the chemical structure (i.e. a thioamide group). Polyhexyl phenylacetamide (PHPA) is used as a reference demonstrating a poor compatibility with PPS. Furthermore, PPS/glass fiber (GF) composites containing PHBTA exhibit enhanced rheological properties, mechanical properties, GF dispersion, and an increase in the length of GFs in the fracture state. To better understand the mechanical properties of PPS/GF40/PHBTA composites, we predict their tensile moduli using the Mori-Tanaka theory and the Halpin-Tsai equation, and the predictions agree well with the experiment results. This study aims to improve flowability in PPS/GF40 composites, thereby ensuring the effective and low cost processing of polymers for practical applications. Moreover, this approach provides further insight into the rheological and mechanical properties of FRP composites.