Surface modification of carbon fiber and the mechanical properties of the silicone rubber/carbon fiber composites

Effects of the incorporation of the PAN‐based carbon fiber (CF) into a room temperature vulcanized silicone rubber (RTV), poly(dimethylsiloxane) (PDMS) containing terminal silanol groups, on the thermal stability and mechanical properties were explored. CF was modified with nitric acid to introduce hydroxyl and carboxyl groups on the CF surface. These functional groups were then treated with an isocyanato silane compound, 3‐isocyanatopropyltriethoxysiane (IPTS) to incorporate trialkoxy groups to the acid‐treated CF to prepare IPTS grafted CF (I‐CF). The alkoxy groups on the surface of I‐CF may undergo the condensation reaction with the silanol groups of RTV to enhance the interfacial interaction between I‐CF and RTV. Morphology of the fractured surface of RTV/CF composites was examined by scanning electron microscopy (SEM). The mechanical properties and thermal stability of the composites were analyzed and rationalized by the increase in the degree of curing of RTV and the enhanced interfacial interaction. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012