Methodological Features of Studying the Contact Angle of Carbon Fibers

A method is proposed for estimating the contact angle of fibrous materials by optical analysis of the meniscus formed due to capillary forces when the sample is immersed in a liquid. The contact angles of wetting of carbon fibers in an epoxy binder at the gelation temperature were assessed. The content of the sizing composition in the studied samples was determined using DSC/TG analysis and the data obtained were correlated with the dynamics of changes in the contact angle. The features of the experiment are shown, and the advantages and disadvantages of the proposed measurement method are considered.