Epoxide materials

摘要

Epoxide materials suitable for use in flexible adhesives are prepared by reacting a diene, such as butadiene or isoprene, with an electron donor, typically an alkali metal, in the presence of a polyepoxide normally in a molar ratio diene:polyepoxide of less than 3:1. The polyepoxide is typically a conventional epoxy resin such as DGBA. The product normally separates into two phases, the upper of which comprises epoxy-terminated diene oligomers with degrees of polymerization of about 6 to 14. This separation may be avoided by incorporating a minor proportion of acrylonitrile into the product by addition to either the original diene or the anionic living polymer immediately before hydrolysis. The products may be cured with conventional epoxide curing agents to give an internally flexibilized adhesive having useful combinations of tensile and shear strengths.