（School of Chemical Engineering and Technology， Harbin Institute of Technology， Harbin 150001， China）
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DOI:
10.7502/j.issn.1674-3962.2013.04.03
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Abstract:
A carbon fiber/polyhedral oligomeric silsesquioxane/carbon nanotube (CFPOSSCNT) hybrid reinforcement was prepared by grafting CNTs onto the carbon fiber surface using octaglycidyldimethylsilyl POSS as the linkage in an attempt to improve the interfacial properties between carbon fibers and an epoxy matrix. Xray photoelectron spectroscopy, scanning electron microscopy, dynamic contact angle analysis and single fiber tensile testing were performed to characterize the hybrid reinforcements. Experimental results show that POSS and CNTs are grafted uniformly on the fiber surface and significantly increase the fiber surface roughness. The polar functional groups and surface energy of carbon fibers are obviously increased after the modification. Single fiber tensile testing results demonstrate that the functionalization does not lead to any discernable decrease in the fiber tensile strength. Interfacial shear strength (IFSS) testing was carried out to investigate the interfacial property of the composites. The results indicate the IFSS enhanced by 105%. The main reason of enhancement of the composite interfacial adhesion is improving of fiber surface wettability, increasing of fiber surface roughness and formation of chemical bonding.