Azonaphthalene sulfonates as polymerization catalysts

A method for the preparation of bisphenol A polycarbonate said method comprising contacting at least one diaryl carbonate with bisphenol A in the presence of a transesterification catalyst, at a temperature in a range between about 180° C. and about 310° C. and a pressure in a range between about 760 and about 1 torr to afford a product polycarbonate, said transesterification catalyst comprising at least one azonaphthalene sulfonate catalyst and at least one co-catalyst.

A method for the preparation of bisphenol A polycarbonate, said method comprising contacting bisphenol A with diphenyl carbonate at a temperature in a range between about 180° C. and about 310° C. and a pressure in a range between about 760 torr and about 1 torr in the presence of at least one azonaphthalene sulfonate and tetrabutylphosphonium acetate, said diphenyl carbonate being present in an amount corresponding to between about 0.9 and about 1.2 moles diphenyl carbonate per mole of bisphenol A, said azonaphthalene sulfonate being present in an amount corresponding to between about 1×10−8 and about 2.5×10−4 moles azonaphtalaene-sulfonate per mole bisphenol A employed, said tetrabutylphosphonium acetate being present in an amount corresponding to between about 1×10−6 and about 1×10−2 moles tetrabutylphosphonium acetate per mole bisphenol A employed.