Surface Modification of Carbon Fiber by Electro-Polymerization: Continuous Production, Thickness Control, Colorization, and Preparation of CFRP

Abstract

Carbon fibers (CFs) have been widely used as reinforcing materials because of their excellent specific strength, specific modulus, corrosion resistance, energy absorption, and other properties. To improve the mechanical properties of CF-reinforced composites, one of the effective methods is to improve the interfacial force between the CF and the polymer through modification of CFs. The aim of this study is to modify the surface of the CF with an environmentally friendly and efficient way and to design a continuous production equipment. In this research, a continuous electro-polymerization equipment was designed, and the surface of the CFs was modified by epoxy or vinyl ether, which was initiated by photoinitiator UVI-6974 without adding any solvent and extra electrolytes. By changing the structure of monomers, polymerization time, voltage, concentration of the initiator, and the distance between CFs and electrodes, the performance and thickness of the polymer layer on the CFs were controllable. The results of scanning electron microscopy and infrared spectroscopy proved that the surface of the CFs was covered by polymers, and some unreacted functional groups remained. The mechanical performances of CF composites prepared from the BDE/DVE-3-modified CFs showed that the interlaminar shear strength improved by 46.98 and 62.02%, and the tensile strength improved by 11.40 and 16.62%, respectively, compared with unmodified CFs. This proved that the interface force between the resin and the CF was greatly improved by the thin polymer layer on the surface of the CF and the unreacted functional groups. On the other hand, if pigments or dyes were added to the polymerization system, colored CFs could be fabricated by this equipment continuously. Because of the solvent-free, low-voltage, and continuous fabrication, this electro-polymerization method has a good industrial prospect.

Relevance of graphene oxide as nanofiller for geometrical variation in unidirectional carbon fiber/epoxy composite

“…The main strategies for matrix strengthening include Z-pinning, 17 dispersion of filler in the epoxy resin, 18 and the CF surface modification. [19][20][21][22] The amalgamation of fillers can easily tune the mechanical and thermal properties of CF/epoxy composites. Nanofillers exhibiting negative CTE is a viable technique to attain thermal stability in CFRP.…”

Designing a 3D structure and a self‐healing technique for advanced polymer composites with outstanding mechanical properties and healing ability

“…22,28,29,[31][32][33][34] Since the interfacial adhesion is a critical factor for the mechanical properties of FRPs, increasing the interface interaction between the fiber and matrix can enhance the mechanical properties. Generally, the modification of fiber surface such as the coating technique [35][36][37][38][39][40][41][42][43][44] and chemical grafting 24,41,45,46 can improve the interfacial adhesion between matrix and fibers. For instance, Liang and co-authors 47 introduced carboxymethyl cellulose (CMC) and GO to the surfaces of CF through hydrogen bonds, and the ILSS of CF/GO/CMC composite increased by 58.93%.…”

Chemical Composition of Nanoglobular Material on the Surface of Rubber Regenerate Prepared by Explosive Circulation Technology

“…The promising properties of the rubber crumbs produced by explosive milling can be explained by the presence of polar groups on its surface. Indeed, a positive effect of improving the performance of various hydrophobic carbon [ 17 , 18 , 19 ] and polymer [ 20 , 21 , 22 ] materials was observed when various polar hydrophilic groups were formed on their surfaces. For example, acrylic acid was grafted onto a polyethylene/polypropylene nonwoven fabric using γ-irradiation.…”