Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE Improving the interface performance of CCF/EP composites through an eco-friendly continuous waterborne-hydrolyzed-silk fibron sizing process, and its interfacial strengthening mechanism.


ABSTRACT
High-modulus continuous carbon fiber (HMCCF) composites face interfacial challenges that limit their mechanical performance, while conventional sizing agents raise environmental concerns. This study introduces a sustainable, water-soluble sizing agent derived from hydrolyzed silk fibroin (HSF) to modify HMCCF surfaces. Characterization reveals that HSF sizing significantly enhances surface energy and introduces active groups (e.g., COOH, NH2), improving fiber wettability and interfacial adhesion with epoxy resin (EP). Optimal performance is achieved at 2 mg/mL HSF concentration (HMCCF-HSF2/EP), where interfacial shear strength (IFSS) and interlaminar shear strength (ILSS) increase to 63.33 and 76.62 MPa, respectively. Mechanistic studies confirm that HSF forms a stress-buffering and energy-dissipating interphase through covalent/hydrogen bonding, enabling efficient stress transfer. This work pioneers a fully bio-based, eco-friendly sizing strategy for high-performance HMCCF/EP composites.