Preparation And Study Of Vinyl Ester Resin/ Modified Carbon Fiber Composites

Among various types of fibers, carbon fibers are usually used as reinforced materials due to it possess a low weight, high tensile strength, high stiffness, high temperature tolerance, high chemical resistance, and low thermal expansion. However, the mechanical properties of the carbon fiber reinforced vinyl ester resin composites depend not only on the intrinsic characteristics of the carbon fiber and the resin, but also on their interfacial properties. It is widely believed that good interfacial adhesion properties are essential to ensure efficient load transfers from resin matrix to reinforcing fibers. However, fiber reinforced polymer composites often possess poor interfacial adhesion which significantly limits their practical application.A novel “coupling agent” N-(4-Amino-phenyl)-2-methyl-acrylamide(APMA) was synthesized to efficiently enhance interfacial interactions between the carbon fiber(CFs) and vinyl ester resin(VE). Fourier transform infrared spectroscopy(FT-IR) and X-ray photoelectron spectroscopy(XPS) were employed to characterize functional groups and chemical compositions of carbon fiber surface, which indicated vinyl groups of APMA were grafted successfully on the surface of CFs. Four different treatments of CFs(pristine CFs, carboxylic-CFs, acrylamide-CFs and APMA-CFs) were used to prepare the CFs reinforced VE composites. The flexural mechanical properties and micro-droplet test was performed to investigate the enhancement effect of coupling agent on interfacial strength of composites. Scanning electron microscopy(SEM) showed that APMA-CFs were uniformly distributed through the matrix, and no open ring holes were found at the cross-section of the composites; furthermore, after micro-droplet test, some matrix still attach to the debonded CF surface. As a result, APMA functionalized CFs improved the flexural strength of the APMA-CF/VE composites by 19.4 %, and significantly improved the interfacial shear strength between APMA-CFs and VE by 90.53 %.The surface treatment of carbon fiber reinforced vinyl ester resin composites adhesive strength by carboxymethylcellulose. Fourier transform infrared spectroscopy(FT-IR) and X-ray photoelectron spectroscopy were employed to characterize functional groups of carbon fiber surface. The interface shear strength test was performed to investigate the interfacial adhension strength of composites. The micromorphology between CFs and the VE matrix were investigated by scanning electron microscopy. The vinyl functionalization on carbon fiber surface compared to untreated carbon fiber,and the interface shear strength increased to 34.7% by microdroplets method.