A study of the impact properties of surface-modified UHMPE-fiber/vinylester composites

Ultra-high-modulus polyethylene (UHMPE) fiber has been treated with oxygen plasma and silane coupling agent to improve the interfacial adhesion between the UHMPE fiber and a vinylester resin. The interlaminar shear strengths of UHMPE-fiber/vinylester composites showed a maximum value at a plasma treatment time of 1 min. This phenomenon was attributed to a change of the surface morphology of the UHMPE fiber with the plasma treatment. The total absorbed energy of the UHMPE-fiber/vinylester composite during penetration in an impact test decreased gradually with increasing plasma-treatment time. The surface flaws of the UHMPE fiber were well developed with increasing plasma-treatment time and this flaw-induced fiber breakage reduced the total absorbed energy of the UHMPE-fiber/vinylester composite during penetration. (C) 1997 Elsevier Science Limited.