TOUGHENING OF EPOXY-RESINS BY MODIFICATION WITH REACTIVE ELASTOMERS COMPOSED OF BUTYL ACRYLATE AND GLYCIDYL (METH)ACRYLATE

Acrylic elastomers with pendant epoxy groups were used to reduce the brittleness of bisphenol-A diglycidyl ether epoxy resin cured with p,p'-diaminodiphenyl sulphone. The elastomers were prepared by copolymerization of butyl acrylate (BA) with glycidyl acrylate (GA) or methacrylate. These copolymers were effective for toughening of the epoxy resin system. The addition of 20 wt% of copolymer (74 mol% BA and 26 mol% GA) led to 60% increase in the fracture toughness of the cured resin at slight expense of its mechanical properties. The glass transition temperatures of cured resins were comparable to that of the parent epoxy resin. The toughening mechanism is discussed in terms of the morphological and dynamic viscoelastic behaviour of the modified epoxy resin system.