Modification of Fe2O3 and its effect on the heat‐resistance of silicone rubber

Abstract By means of the wet chemical surface modification, the surface of Fe 2 O 3 was modified by vinyltrimethoxysilane (VTMS). Infrared spectroscopy (IR) was used to investigate the structure of the modified Fe 2 O 3 , and the result showed that VTMS has been attached onto the surface of Fe 2 O 3 . Effect of VTMS concentration on the active index of the modified Fe 2 O 3 was also studied, and the result indicated that the active index of the modified Fe 2 O 3 increases with the increase of VTMS concentration and the optimal concentration of VTMS is 12 wt %. The effect of the modified Fe 2 O 3 on the tear strength of silicone rubber before and after aging was studied and it was found that in comparison with the unmodified Fe 2 O 3 the addition of the modified Fe 2 O 3 results in the significant increase of the tear strength before ageing because of the increase of the crosslinking density of silicone rubber. The tear strength of silicone rubber filled with the modified Fe 2 O 3 after ageing is higher than that with the unmodified Fe 2 O 3 , indicating that the modification of Fe 2 O 3 can improve the heat‐resistance of silicone rubber owing to the fine dispersion of the modified Fe 2 O 3 in silicone rubber. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009