Low-density (0.18–0.31 g/cm3), flame-retardant closed cell silicone foams (SiFs) were successfully obtained through dehydrogenation at room temperature. Moreover, a flame-retardant system for SiF composites was obtained through a synergistic combination of French chalk (FC)/hollow glass beads (HGB). The mechanical properties, flame retardancy, and thermal stability of SiF composites with FC and HGB were tested using the tension test, limiting oxygen index (LOI), UL-94 test, cone calorimeter, and thermogravimetry. The mechanical properties of SiFs could be significantly improved by interfusing FC. The fire retardancy of the SiFs could be prominently improved by adding FC and HGB. With 50 wt% FC, the SiF achieved the UL-94-V0 rating with the LOI value of 41.6%. Remarkably, the addition of 30 wt% FC and 1 wt% HGB significantly reduced the peak heat release rate by 59.9%, total heat release by 40.9%. TG test showed that FC and HGB can promote the char formation in the degradation process of SiFs. The initial decomposition temperature of SiF with 30 wt% FC and 1 wt% HGB was 445.0 °C and the residue at 900.0 °C was 81.0%, which were noticeably higher than that of pure SiF. Through the analysis of the results of this experiment, it was a promising strategy for preparing flame retardant SiFs with improved mechanical performance and thermal stability by adding FC and HGB.

International Seminar on Fire and Explosion Hazards (9; 2019; Saint Petersburg, Russia). Proceedings of the Ninth International Seminar on Fire and Explosion Hazards [Электронный ресурс]. Vol. 2: 21-26 April 2019, Saint Petersburg, Russia / Peter the Great St. Petersburg Polytechnic University, Autonomous Non-Profit Organization "Fire and Explosion Safety", Gefest Holding Ltd ; [edited by A. Snegirev [et al.]. — Электрон. текстовые дан. (1 файл : 98,7 Мб). — Saint Petersburg, 2019. — Загл. с титул. экрана. — Свободный доступ из сети Интернет (чтение, печать, копирование). — Adobe Acrobat Reader 7.0. — <URL:http://elib.spbstu.ru/dl/2/k19-97.pdf>. — <URL:http://doi.org/10.18720/SPBPU/2/k19-97>.