a temperature of 165 u00b0 c and a further 50 ml of dmso added the reaction was allowed to proceed for 8 hours at 165 u00b0 c and a high yield u2267 95 polymer was recovered as before the polymer was soluble in dmso and nmp solvents which are often used in membrane casting formulations both porous and nonporous membranes were cast from this copolymer using u02dc 15 polymer in nmp when the solution was allowed to evaporate completely on a glass plate in a vacuum oven at 55 u00b0 60 u00b0 c a tough flexible transparent film was obtained when the solution was cast on a glass plate and immersed in water a porous membrane resulted other characteristics are described in the attached table preparation of a random copolymer from bisphenol i bisphenol a and dcdps bisphenol a 11 415 g 0 050 mol bisphenol i 19 721 g 0 050 mol and an aqueous solution of sodium hydroxide 10 00 g 0 25 mol was mixed with dmso 50 ml and toluene 150 ml in a resin kettle the flask was equipped with a mechanical stirrer nitrogen inlet thermocouple and dean stark trap the mixture was stirred at reflux for 4 hours until no more water was removed and then the reaction temperature was increased to 150 u00b0 c by distilling off toluene the sulfone monomer dcdps 28 716 g 0 100 mol was added as a slurry in toluene and the remainder was.