New poly(arylene ether)s with pendant phosphonic acid groups

Soluble brominated poly(arylene ether)s containing mono- or dibromotetraphe nylphenylene ether and octafluorobiphenylene units were synthesized. The po lymers were high molecular weight (weight-average molecular weight = 115,10 0-191,300; number-average molecular weight = 32,300-34,000) and had high gl ass-transition temperatures (> 279 degreesC) and decomposition temperatures (> 472 degreesC). The brominated. polymers were phosphonated with diethylp hosphite by a palladium-catalyzed reaction. Quantitative phosphonation was possible when 50 mol % of a catalyst based on bromine was used. The diethyl phosphonated polymers were dealkylated by a reaction with bromotrimethylsil ane in carbon tetrachloride followed by hydrolysis with hydrochloric acid. The polymers with pendant phosphonic acid groups were soluble in polar solv ents such as dimethyl sulfoxide and gave flexible and tough films via casti ng from solution. The polymers were hygroscopic and swelled in water. They did not decompose at temperatures of up to 260 degreesC under a nitrogen at mosphere. (C) 2001 John Wiley & Sons, Inc.