Carbon fibers modified with silicone peroxide containing vinyl groups for silicone rubber reinforcement

•A method to improve the interfacial properties of carbon fibers was reported.•This method has no damage to the carbon fibers confirmed by SEM.•The Si-CH=CH2 groups was chemically bonded to CFs surface.•The IFSS of CFs-VTPS/PDMS increased significantly.

A silicone peroxide, tris(tert-butyldioxy)-vinyl-silane (VTPS), was adopted for carbon fibers (CFs) surface modification to improve the mechanical properties of CFs reinforced polydimethylsiloxanes (PDMS) composites. FT-IR and XPS confirmed that the Si-CH=CH2 groups, which could generate covalent bonds between CFs and PDMS, were chemically bonded to CFs surface. And the method gave no obvious damage to CFs as shown by SEM and tensile strength analysis. After VTPS modification, the interfacial shear strength (IFSS) between CFs and PDMS was increased, and then the mechanical properties of CFs/PDMS composites were greatly improved (tensile strength from 0.59 to 0.90 MPa, tear strength from 0.83 to 3.65 kN/m).