Influence of sizing molecular weight on the properties of carbon fibers and its composites

Three different molecular weight of sizing agent on the performances of carbon fibers and carbon fibers composites are investigated. Atomic force microscopy (AFM) was used to characterize carbon fiber surface topographies. Wetting and surface energy along with contact angles were determined by the dynamic contact angle analysis test (DCAT). The single fiber strengths and Weibull distributions were also studied in order to understand the effect of sizing agent on the carbon fibers. At the same time, the interfacial shear strength (IFSS) and hygrothermal aging test have been used to study the effect of fibers coatings on the adhesion of surface. The results revealed that the S_2 sizing agent on the carbon fiber interface properties and IFSS was better than those of other sizing agents.

► First report about the influence of molecular weight of sizing agent.
► The molecular weight of sizing agent has an important influence to carbon fibers.
► The sizing agent has an important influence to the carbon fibers composites.
► This research has concluded that S_2 sized carbon fibers showed better properties.
► The sizing agent S_2 sized carbon fiber has better aging resistant properties