The effect of polybutadiene interlayer on interfacial adhesion and impact properties in oxygen-plasma-treated UHMPE fiber epoxy composites

In order to improve the interfacial adhesion and impact properties of ultra -high modulus polyethylene (UHMPE) fiber/epoxy composites at the same time, the fiber coating technique was combined with the oxygen plasma treatment. The UHMPE fiber was treated with oxygen plasma and thin polybutadiene (PB) coating was introduced. PB coating decreased the interfacial adhesion and increased the impact property of the oxygen-plasma-treated UHMPE fiber/epox y composites. However, oxygen-plasma-treated and PB-coated UHMPE fiber/epox y composites show improved interfacial adhesion, flexural properties and im pact property in comparison with the untreated control UHMPE fiber/epoxy co mposites. Oxygen plasma treatment introduces micro-pittings on the UHMPE fi ber surface. These micro-pittings improved interfacial adhesion and flexura l properties and decreased impact properties through mechanical interlockin g. Thin PB coating cannot exclude this mechanical interlocking effect compl etely and there are imperfect wetted UHMPE fiber surface regions in which e ffect mechanical interlocking can occur. Stress transfer through the viscou s PB interlayer also contributes to the interfacial adhesion and flexural p roperties of PB-coated UHMPE fiber/epoxy composites. The impact property of PB-coated UHMPE fiber/epoxy composites is due to low modulus PB interlayer . (C) 1999 Elsevier Science Ltd. All rights reserved.