Properties of Surface Thermo-chemically Modification of Carbon Fibers and Their Vinyl Ester Composites

In order to improve the weak interface performance of the carbon fiber/vinyl ester composites, we modifed the carbon fiber via surface oxidation and grafting and at the same time changed the resin formulation. It is demonstrated that the interface performance of CF/VE composites has been improved according to the results of SEM characterization, mechanical property tests, DMA tests as well as adhesion parameters calculation. The SEM pictures demonstrate that the specific surface area of the modified CF/VE composites is increased, and the interface strength is greater than the strength of the resin while the unmodified CRFP's is not. The oxidation temperature should be set at least over 210℃ according to the TGA testing result. CF/VE composites show better properties when the carbon fibers are oxidated at 600 ℃. The interlaminar shear strength increases at first and then decreases as the coupling concentration increases. When the mass concentration is 1%, the sheer strength rises to the highest, increasing by 74. 3% compared to that of the unmodified CF/VE composites. The glass transition temperature is improved by 10 ℃ from the dynamics mechanics curves. The interface performance of the modified CF/VE composites is improved, confirmed by the quantitative analysis of adhesion parameters.