Environmentally friendly water-soluble epoxy emulsions nano sphere improved the interfacial performance of high modulus carbon fiber reinforced epoxy composites based on robust van der Waals force

High modulus carbon fibers (CFs) are widely desirable in aerospace, robotics, etc. However, their high degree of graphite microcrystalline structure leads to poor interfacial properties with host matrices, deteriorating the mechanical properties of carbon fiber reinforced polymer composites (CFRPs). Here, to improve interfacial properties of CFRPs, we present to construct a uniform and continuous active sizing nanolayer on the surface of CFs via synthetic water-based epoxy (WEP) emulsion nanospheres with strong van der Waals force. The WEP emulsions were prepared by introducing polar polyethylene glycols into epoxy resin chain. The modified CFRPs showed robust interfacial properties, improving by 25% over the untreated counterparts. Moreover, the proposed method can retain monofilament tensile strength of fibers and protect CFs from being destroyed during processing at industrial scales. This work opens an avenue toward the development of materials with superior interfacial performance for various inert high modulus fibers.

Automated summary

High modulus carbon fibers are widely used in aerospace and robotics, but their high degree of graphite microcrystalline structure leads to poor interfacial properties with host matrices in carbon fiber reinforced polymer composites (CFRPs). To address this issue, a method involving synthetic water-based epoxy emulsion nanospheres was proposed to improve the interfacial properties of CFRPs. The modified CFRPs showed enhanced interfacial properties by 25% compared to untreated counterparts, while also retaining monofilament tensile strength and protecting CFs during industrial processing. This approach opens up possibilities for developing materials with superior interfacial performance for various inert high modulus fibers.