Directly coating silanized nanocrystalline cellulose on carbon fiber for enhancing the interfacial adhesion of carbon fiber/epoxy resin composites

A continuous coating was used to treat carbon fibers (CFs) with silanized nanocrystalline cellulose (NCC) for enhancing the interfacial adhesion of CF/epoxy composites. The NCC was silanized with 3-aminopropyltriethoxysilane and then was applied to modify the CF surface for increasing the surface roughness of the CF and achieving chemical bonding between the CF and epoxy resin. The morphologies of the modified CFs with different contents of silanized NCC were characterized by a scanning electron microscope (SEM) and the performance of the silanized NCC-coated CF/epoxy composites was characterized by an interfacial shear strength (IFSS) test and a flexural test. The experimental results indicated that excessively silanized NCC had reduced interfacial properties due to the agglomeration of NCC. Notably, increases of 94.22% in IFSS and 23.24% in flexural strength were achieved in 0.3wt% silanized NCC-coated CF/epoxy composites compared to the desized CF/epoxy composites. As a result, dispersion of silanized NCC in the interface regions was one of the critical factors influencing the interfacial properties of the composites. Coating CFs with silanized NCC provided valuable method based on an abundant raw material for strengthening the interfacial adhesion between CF and epoxy resin matrix. POLYM. COMPOS., 40:E744-E752, 2019. (c) 2018 Society of Plastics Engineers