Flame retardancy of silicone rubber foam containing modified hydrotalcite

Silicone rubber material (silicone rubber foam [SRF]) composites is a new type of polymer foam material, which has the characteristics of high elasticity and high-temperature resistance, but this material is flammable. In order to improve the flame retardant properties of SRF composites. The co-precipitation method is used to prepare modified hydrotalcites (LDHs) with different Ce/Al molar ratios for application to SRF composites. X-ray diffraction, scanning electron microscopy (SEM), and FT-IR are used to characterize modified LDHs with different Ce/Al molar ratios. The combustion performance, thermal decomposition, and mechanical properties of composite materials are studied through the limiting oxygen index (LOI), vertical combustion test, thermal gravimetric analysis, cone calorimeter test, and SEM. Results show that the LOI value of SRF composite with addition of 3% LDHs at a Ce/Al molar ratio of 0.3:0.7 is 31.2%, and the heat release rate, the smoke production rate, and total smoke production of the SRF composite are reduced by 53.64%, 34.92%, and 66.19%, respectively. Besides, the addition of modified LDHs leads to increase in the thermal stability of the SRF composite. The results obtained from this study can provide guidance for the development of environmentally friendly SRF.

Automated summary

In this study, the flame retardant properties of silicone rubber foam (SRF) composites were improved by using modified hydrotalcites (LDHs) with different Ce/Al molar ratios. The addition of LDHs resulted in a significant reduction in heat release rate, smoke production rate, and total smoke production, as well as an increase in thermal stability of the SRF composite. These findings provide guidance for the development of environmentally friendly SRF.