Novel stable aqueous emulsion of vinyl sizing agents for strong adhesion force between carbon fiber and vinyl resin

The sizing process is the best surface modification method to improve the interfacial properties of carbon fiber reinforced resin composites. In order to reinforce the interfacial adhesion of carbon fiber(CF)/vinyl resin (VE) composites, one novel emulsifying main slurry (NYDA) and resin (NE) were designed and synthesized from the view of the covalent bond between the CF and VE. The slurry NY-NE (2 wt% emulsion) exhibited excellent storage stability for three months. For introducing abundant active functional groups (C=C) to the NY-NE sized carbon fibers (NCF) surface, the interlaminar shear strength (ILSS) of NCF/VE composites (62.44 MPa) has increased by 69.31 % compared with unsizing carbon fiber (UCF)/VE composites (36.88 MPa). Moreover, the interfacial adhesion between CF and VE was also enhanced by the formation of C=C groups on the CFs surface to react with the VE effectively, which reinforced the interfacial layer to well transfer the load among the composite resin.