Preparation and characterization of flame retardant epoxy resins based on phosphorus-containing biphenyl-type phenolic resin

Abstract

AbstractA phosphorus-containing biphenyl-type phenolic resin (PBP) was prepared by dehydration polycondensation of the DOPO-disubstituted 4,4’- biphenyldimethanol compound (BDCA-2DOPO) with phenol in the presence of strong Lewis acid , in which BDCA-2DOPO was prepared by the reaction of DOPO with 4,4'-biphenyldicarboxaldehyde. The PBP resin has been evaluated as the curing agent of o-cresol epoxy resins. Experimental results indicated that the PBPcured epoxy resins exhibited good thermal stability, high char yields at 700 oC and outstanding flame retardant properties. UL 94 V-0 classifications could be obtained when the phosphorus loading in the epoxy resin is higher than 1.8 wt%.