Facile, one-pot synthesis of phosphinate-substituted bisphenol A and its alkaline-stable diglycidyl ether derivative

A new phosphinate-substituted bisphenol A, 1,1-bis(4-hydroxyphenyl)-1-(6-oxido-6H-dibenz <c,e> <1,2> oxaphosphorin-6-yl)ethane (1), was prepared by a facile, one-pot procedure. In addition, a reaction mechanism for the preparation of (1) was proposed. Based on (1), a diglycidyl ether derivative (2) was prepared and cured by commercially-available curing agents. The structures of (1-2) were confirmed by IR, high-resolution mass, 1-D and 2-D NMR spectra. Properties such as glass transition temperature, coefficient of thermal expansion, thermal decomposition temperature, and flame retardancy of the resulting thermosets were evaluated and compared with those of the thermosets of diglycidyl ether of bisphenol A. The resulting epoxy thermosets show high T_g, low thermal expansion, good thermostability and excellent flame retardancy.