Reinforcement of polyamide 6 with carbon fiber surface modified by a polar cross-linked network interfacial phase

Carbon fiber-reinforced polyamide 6 (CF/PA6) composite materials have low relative den-sity, high specific strength, and high specific modulus. However, the surface of the CF is smooth and chemically inert, resulting in poor interfacial adhesion in CF/PA6 composites, thereby limiting its application range. Herein, an epoxy resin emulsifier with hydrophilic ends and lipophilic middle was synthesized. After sizing, the surface chemical activity and roughness of the CF were higher. The tensile strength of the prepared CF/PA6 composite material was increased by 38.6%, and the impact strength was increased by 26.4%. By testing the tensile strength and wettability of the CF, as well as the dynamic thermo-mechanical properties and rheological behavior of the CF/PA6 composites, the influence of the sizing agent on the properties of CF and the interfacial properties of CF/PA6 composites was evaluated, and its mechanism of action is discussed herein.(c) 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).