Modification of epoxy surfaces with different polyvinylalcohol polymers



An epoxy resin, consisting of diglycidylether of bisphenol A (DGEBA) and methyltetrahydrophtalic anhydride (MTHPA), was cured against peel-plies coated with different poly(vinylalcohol-co-vinylacetate) (PVOH). The epoxy polymer surface was characterized with X-ray photo electron spectroscopy (XPS), contact angle measurements, and scanning electron microscope (SEM). PVOH, which is a water soluble polymer, was detected at the cured epoxy polymer surface with XPS after washing with hot water. The PVOH polymer at the outermost surface has hydroxyl groups, which can react with both the adhesive and the epoxy resin. The modified epoxy composite surfaces were adhesively bonded with a polyurethane and an epoxy adhesive. Improved adhesion was obtained between modified epoxy composite surfaces and different adhesives. © 1993 John Wiley & Sons, Inc.