Interface characterization by pull-out test between high modulus polyethylene fibre and an unsaturated polyester resin

Abstract

The observation of the pull-out conditions for a monofilament outside a matrix has been applied to a wide variety of organic or inorganic materials, as a direct method of interface characterization. In the case of High Modulus PolyEthylene (HMPE) it has been demonstrated that oxygen plasma treatments or gamma irradiation modify the fibre surface properties and improve the adhesion between the fibre and a resin. In this study, the effect of different plasma treatment times and the irradiation conditions leading to different gel fractions have been tested. For plasma treatments, an appreciable improvement occurs even for the lower residence times (2 sec). The gamma irradiation has only the same efficiency for the condition leading to a high gel fraction (0.75). These results agree with InterLaminar Shear Strengths (ILSS) values measured in three-point bending on HMPE/epoxy laminates