Effect of emulsifier content of sizing agent on the surface of carbon fibres and interface of its composites

▶ First report about the influence of emulsifier content of sizing agent. ▶ The emulsifier content of sizing agent has an important influence to carbon fibres. ▶ The sizing agent has an important influence to the carbon fibres composites. ▶ This research has concluded that E-3 sized carbon fibres showed better properties. ▶ The sizing agent E-2 sized carbon fibre has better ageing resistant properties. In this work, carbon fibres were sized with different emulsifier content sizing agent in order to improve the performances of carbon fibres and the interface of carbon fibres composites. The surface characteristic changing after modification was investigated by scanning electron microscopy (SEM), atomic force microscopy (AFM). Wetting and surface energy along with contact angles were determined by the dynamic contact angle analysis test (DCAT). At the same time, the single fibre strengths and weibull distributions were also studied in order to understand the effect of the emulsifier content of sizing agent on the carbon fibres. The interfacial shear strength and hygrothermal ageing of the composites were measured which showed a different enhancement, respectively. The results revealed that sizing agent E-3 showed better interface adhesion between fibres and matrix and sizing agent E-2 sized carbon fibre has better ageing resistant properties.