A Silicone Rubber/Hollow Glass Microsphere Composite Coating: Thermal Stability/Insulation and Mechanical Property

ABSTRACT The growing demand for advanced thermal insulation materials in aerospace, automotive, and renewable energy sectors is accelerating the development of high‐performance thermal insulation coatings. This study successfully developed a novel composite thermal insulation coating (GMQ) with a silicone rubber matrix uniformly filled with hollow glass microspheres and quartz powder. The coating's microstructure and chemical composition were systematically characterized using scanning electron microscopy, Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric analysis (TGA), confirming uniform dispersion of functional fillers and excellent bonding with the matrix. Performance testing demonstrated exceptional initial thermal insulation properties, with a thermal conductivity as low as 0.177 W/m K. Research indicates that this thermal insulation effect stems from the synergistic interaction between surface heat reflection and complex internal heat flow pathways. Notably, after 7 days of thermal aging treatment, although the coating's thermal conductivity increased to 0.272 W/m K and its tensile shear strength decreased from 4.09 to 3.42 MPa, its actual thermal insulation functionality remained stable. This research not only developed a promising high‐performance thermal insulation material but also provided significant insights into addressing performance degradation in polymer‐based composites under prolonged thermal exposure.