Abstract: Four kinds of modified montmorillonite/silicone rubber foam composites (SiFs) were prepared by high temperature vulcanization method. The flame retardant and mechanical properties of the silicone rubber foam composites containing different modified montmorillonite were studied. Oxygen index tester, cone calorimeter and mechanical tensile instrument were used to measure the flame retardant and mechanical properties of SiFs. The results of oxygen index tester, cone calorimeter, thermogravimetric analyzer and mechanical tensile tester show that cetyltrimethyl ammonium bromide modified montmorillonite (CMMT) has a significant effect on the flame retardancy and mechanical properties of SiFs. When the addition of CMMT is 3%，The limiting oxygen index value of SiFs reaches 28.5% and reaches V-0 level. Compared with pure SiF, the elongation at break of its increased to 278%, and the peak heat release and total smoke production decreased by 20.8% and 39% respectively. CMMT promotes the formation of dense carbon layer of SiFs, which significantly improves the flame retardancy of SiFs.

Key words: montmorillonite, silicone rubber foam, cetyltrimethylammonium bromide, flame retardant, smoke suppression