Study on an oxygen plasma treatment of a basalt fiber and its effect on the interlaminar fracture property of basalt/epoxy woven composites

In this study, the effects of surface treatment of a basalt fiber by low-temperature atmospheric oxygen plasma on the interlaminar fracture behavior of basalt/epoxy woven composites were investigated. A commercial basalt fiber and its woven fabric were treated by low-temperature atmospheric oxygen plasma. Contact angle was measured to examine the changes in wettability of the basalt fiber. The chemical and morphological changes were characterized by using XPS and FE-SEM. Basalt/epoxy woven composites were fabricated with and without oxygen plasma treatment, and their interlaminar fracture toughnesses were compared. The results showed that the wettability of the basalt fiber was remarkably increased, accompanied by physical etching and by the formation of chemical functional groups containing oxygen and nitrogen on the fiber surface. The interlaminar fracture toughness of basalt/epoxy woven composites was improved by 16% by oxygen plasma treatment. SEM results on the fractured surface exhibited epoxy resin adhered well around the basalt fibers of the oxygen plasma-treated specimen compared to that of the untreated specimen. An adhesive force between fiber/resin interfaces was improved by oxygen plasma treatment, and this increased the interlaminar fracture toughness of basalt/epoxy woven composites.