Epoxy resins from novel monomers with a bis-(9,10-dihydro-9-oxa-10-oxide-10-phosphaphenanthrene-10-yl-) substituent

Abstract

A new diepoxide and a new diamine, both bearing bis-(9,10-dihydro-9-oxa-10-oxide-10-phosphaphenanthrene-10-yl-)-substituted methylene linkages, were prepared through the reaction of 9,10-dihydro-oxa-10-phosphaphenanthrene-10-oxide with benzophenone derivatives via a simple addition reaction followed by a dehydration reaction. These two compounds were used as monomers for preparing cured epoxy resins with high phosphorus contents. The resultant epoxy resins showed high glass-transition temperatures (between 131 and 196°C). All of the cured epoxy resins exhibited high thermal stability, with 5% weight loss temperatures over 316°C, and excellent flame retardancy, with limited oxygen index values of 37-50.