Louisville, Kentucky - New research from Bayer MaterialScience claims that adding polyurethanes to an epoxy resin creates a tougher, more durable adhesive. The mixture capitalises on polyurethane's toughness, and the resulting hybrid adhesive reduces the brittleness to which stand-alone epoxy adhesives are prone, BMS said in a 16 Oct news release.
Dr Jay Johnston, senior scientist, Bayer MaterialScience llc, will discuss the advantages of adding polyurethane to an epoxy-based adhesive during his 23 Oct presentation, "Hybrid Adhesives with Improved Adhesion and Increased Temperature Resistance," at the Adhesive & Sealant Convention 2012 conference and expo.
Johnston's discussion will explain how adding a blocked polyurethane prepolymer into the backbone of an epoxy adhesive offers improved cure rates, increased temperature resistance and better adhesion to many different substrates, BMS said. He will also explain how polyurethane prepolymers blocked with phenolic compounds unblock at room temperature in the presence of a strong amine without any additional heat.
BMS said other benefits include increasing the epoxy resin's reactivity, and improving tear resistance, toughness, and impact resistance through phase separation of the soft PU segment from the epoxy matrix.
Johnston will also provide results from several comparative tests of epoxy adhesives with and without blocked polyurethane prepolymers that further demonstrate the benefits of adding these polyurethanes to commercial epoxy adhesives.