Thermally conductive and electrically insulative polypropylene composites based on polymethylsilsesquioxane microparticles

This study investigates the development of polypropylene (PP) composites reinforced with polymethylsilsesquioxane (PMSQ) microparticles at varying concentrations (0, 5, 10, and 15 wt%). The composites were produced via melt blending to evaluate the effect of PMSQ on their thermal, thermo-mechanical, and electrical properties. Differential scanning calorimetry (DSC) revealed slight changes in melting temperature, crystallization temperature, and crystallinity level with PMSQ addition. Thermogravimetric analysis (TGA) showed improved thermal stability, with residual mass increasing proportionally to PMSQ content. Dynamic mechanical analysis (DMA) indicated enhanced stiffness, as showed by a 32% increasing in storage modulus at 15 wt% PMSQ. However, the glass transition temperature remained unchanged. The thermal conductivity was improved by 20% with 10 wt% PMSQ, coupled with a tenfold increase in electrical resistivity. These results suggest that PP/PMSQ composites are promising candidates for applications requiring efficient heat dissipation and high electrical insulation, such as in electrical and electronic systems.