Effect of Melamine‐Modified Zinc Phytate on the Flame Retardancy and Smoke Suppression of Silicone Rubber Foams

ABSTRACT Melamine‐modified zinc phytate (PA‐MA‐Zn) was successfully synthesized by the direct precipitation method, and then silicone rubber foams (SiFs) with PA‐MA‐Zn were prepared. The test results showed that PA‐MA‐Zn could considerably enhance the flame retardancy and smoke suppression properties of SiFs. Specifically, SiFs with 5 wt% PA‐MA‐Zn achieved a limiting oxygen index value of 29.4%, and the total heat release and total smoke production were reduced by 37.35% and 70.72%, respectively, compared with pure SiFs. This might be attributed to the better flue gas adsorption capacity of the expanded carbon layer formed by the synergistic effect of MA and PA in SiFs. Furthermore, the catalytic effect of phytate and zinc substantially improved the strength of the carbon layer, which could effectively block the transfer of heat and oxygen on the surface of SiFs.