Improved Adhesive Properties Of High-modulus Polyethylene Structures
Published 1993 · Materials Science
The adhesion of oriented, high-modulus polyethylene-structures to epoxy resins is greatly enhanced by pretreatment with oxidizing acids. For KMnO4/H2O/H2SO4 treatment a maximum increase in adhesion, as determined by pull-out tests, of 600% was found. Chromic and chlorosulphonic acid treatment improves the adhesion with 550% and 300% respectively. Moreover, this improvement was obtained without substantially affecting the mechanical properties. The modulus remained the same, whereas tensile strength decreased by less than 10% after this treatment. By monitoring the changes in surface topography (SEM) and surface composition (X-ray photoelectron spectroscopy) the improvement in adhesion could be related to the introduction of functional oxygen-containing groups, i.e. hydroxyl, carbonyl, carboxyl. Furthermore, at the highest level of adhesion obtained the failure mode changed from interface controlled to shear failure within the polyethylene structure.