Enhanced mechanical properties of carbon fibre/epoxy composites via in situ coating‑carbonisation of micron-sized sucrose particles on the fibre surface

Surface modification of carbon fibres (CFs) is an important part of the interfacial study of CF composites. Traditional modification methods feature complicated production processes and a variety of influential factors. The modification technology utilized may cause fibre damage. To solve this problem, a simple and efficient CF surface modification method involving the in-situ carbonisation of micron-sized sucrose particles, is proposed in this paper. Sucrose crystals were introduced on the surface of the CFs by an ethyl acetate suspension coating and carbonised in atmosphere at moderate temperatures. Carbonisation of sucrose at 290 °C in air resulted in not only the formation of a large amount of CO content, but also in micron-sized particles. The attachment of these uniform and reactive particles to the CF surfaces resulted in a markedly improved impact resistance level of the carbon fibre reinforced polymer (CFRP) composite. Meanwhile, the interfacial shear strength (IFSS) and interlaminar shear strength (ILSS) of the carbonised sucrose-deposited fibre/epoxy composites increased by 20.8% and 13.8%, respectively. This method provides a novel, convenient, and effective approach to enhance the mechanical properties of high-performance CFRPs.