Thermal, physical and flame-retardant properties of phosphorus-containing epoxy cured with cyanate ester

Two phosphorus-containing advanced epoxy resins were obtained by chain-extension of diglycidyl ether of bisphenol-A epoxy (DGEBA) resin with 2-(6-oxido-6H-dibenz(c,e)(1,2)-oxaphosphorin-6-yl)-1,4-benzenediol (DOPOBQ), at different stoichiometric ratios. The phosphorus-containing advanced epoxy was separately cured with various dicyanate esters to form flame-retardant epoxy/cyanate ester systems. The effects of phosphorus content and dicyanate ester structure were studied, and compared with those of the control (advanced bisphenol-A epoxy) system. The DOPOBQ-containing epoxy/cyanate ester systems exhibited higher glass transition temperatures, better dimensional stability and better thermal stability.