Polydimethylsiloxane Thermal Insulation Composite Elastomer Filled with Hollow Glass Microspheres

Abstract

This study aims to enhance the thermal insulation properties of polydimethylsiloxane by the incorporation of hollow glass microspheres (HGM) as a functional filler, while evaluating the trade-offs in mechanical, surface, and optical performance. The thermal conductivity, tensile mechanical properties, surface characteristics, and optical transparency of the composites were investigated. The incorporation of 10 wt.% hollow glass microspheres decreased the thermal conductivity coefficient by 56.3%, achieving a minimum value of 0.059 W·m^–1·K^–1. However, this enhancement came at the expense of optical transparency, surface properties, and a significant reduction in the critical elongation at the break. The results demonstrate that HGM-filled polydimethylsiloxane composites are promising materials for thermal insulation applications where transparency and stretchability are secondary to thermal performance.