High-Temperature-Resistant Organic–Inorganic Hybrid Microspheres with Superior Thermal Expansion Properties

An organic–inorganic hybrid microsphere with excellent thermal expansion properties was successfully synthesized and investigated. This study systematically examined the effects of various types and concentrations of silica-modified acrylic monomers on the thermal expansion characteristics of the microspheres. Furthermore, to enhance the high-temperature durability of thermal expansion microspheres (TEMs), an acrylate-modified polyhedral oligomeric silsesquioxane (MP-POSS) with high compatibility was synthesized as a cross-linker, and its synergistic effect on the thermal properties of TEMs was thoroughly analyzed. The core/shell polymers were characterized in terms of their chemical structures, thermal expansion behaviors, and morphology. Experimental results indicated that when triisopropylsilyl methacrylate (TISMA) was incorporated at 20 wt % and the bifunctional acrylate ester of MP-POSS was utilized as the cross-linker, the optimized TEMs exhibited a maximum expansion temperature of 230 °C, which was 23 °C higher than that of the conventional acrylate-based TEMs. Additionally, the foamed microspheres maintained their structure at 190 °C for 39 min without significant collapse. It was believed that the hybrid microspheres would provide a potential application value to fabricate lightweight materials that require high-temperature treatment, such as ceramics, plastics, rubber, and other industrial products.