Self-assembled nano-polymers modified water-based sizing agent for enhancing the dual interfacial properties of carbon fibre/epoxy resin composites

The dual interface-enhanced sizing agents are prepared to simultaneously exhibit high surface roughness and high interfacial wettability through self-assembled nano-polymers. Five self-assembled nano-polymer modified water-based sizing agents (NPSAs) with various cross-linking structures are synthesized in this paper. It is demonstrated strong characteristics of homogeneous particle size in the 90-200 nm range and heat stability below 200 degrees C. NPSAs significantly improve the CF surface properties of both surface roughness and surface energy, with reached high values of 13.89 nm and 40.22 mN m-1. Notably, the interlaminar shear strength (ILSS), flexural strength, and fracture toughness (KIC) of CF/ER composites sized by NPSAs are enhanced to 70%, 51%, and 120% compared with the unoptimized composite, respectively. The NPSA reinforcing mechanism, enhancing interfacial properties of CF/ER composites in the interfacial interlocking and adhesion ability, was clarified by the coefficient of thermal expansion (CTE1). Additionally, NPSAs have the advantage of being applicable for simple one-pot synthesis methods, and secondly, no toxic solvents were used.

Automated summary

The dual interface-enhanced sizing agents were prepared using self-assembled nano-polymers to achieve high surface roughness and interfacial wettability. Five self-assembled nano-polymer modified water-based sizing agents (NPSAs) with different cross-linking structures were synthesized. NPSAs exhibited homogeneous particle size in the range of 90-200 nm and heat stability below 200 degrees C. The CF surface properties were significantly improved by NPSAs, with surface roughness and surface energy reaching high values of 13.89 nm and 40.22 mN m-1. The CF/ER composites sized by NPSAs showed enhanced interlaminar shear strength (ILSS), flexural strength, and fracture toughness (KIC) by 70%, 51%, and 120% compared to the unoptimized composite, respectively. The reinforcing mechanism of NPSAs was clarified through the coefficient of thermal expansion (CTE1), which improved the interfacial interlocking and adhesion ability of CF/ER composites. Additionally, NPSAs have the advantages of simple one-pot synthesis methods and no use of toxic solvents.