An epoxy-terminated structural adhesive. II. Curing,adhesive strength,and flammability characteristics

Curing characteristics and the curing schedule of an epoxy-terminated polymer (ETP) were investigated using diaminodiphenyl ether (DADPE), diaminodiphenyl sulfone (DADPS), diaminodiphenyl methane (DADPM), and the hardener of a commercial epoxy, two-pack Araldite (Ciba-Geigy), as curing agents. The adhesive strength of the ETP was measured by various ASTM methods like lap-shear, cohesion, and adhesion tests on metal-metal, wood-metal, wood-wood, and metal-polymer interfaces. All these results are compared with Araldite GY250, a two-pack Araldite (Ciba-Geigy). The flame retardancy of virgin ETP, ETP-Araldite GY250 blends, and various commercial-grade fire-resistant epoxies was measured. A structure flammability correlation for the ETP-Araldite GY250 blends is also reported.