Interfacial microstructure and properties of poly (phenylene benzobisoxazole) fiber grafted with graphene oxide via solvothermal method

► A facile one-pot process for grafting GO onto PBO fiber surface using solvothermal method was proposed. ► Solvothermal method provides a supercritical fluid ambient for forming a hierarchical structure on the surface of PBO fiber. ► The hierarchical structure effectively enhanced the interfacial adhesion between PBO fibers and matrix. ► The enhancement effect mainly comes from the increasing chemical bonding, improving wettability and mechanical interlocking.