Synthesis, characterization, and study of the thermal properties of new poly(arylene ether 1,3,4-oxadiazole)s

A series of new poly(arylene ether 1,3,4-oxadiazole)s has been prepared by nucleophilic displacement of aromatic dihalides with aromatic potassium bis phenates in diphenyl sulfone at elevated temperatures. The polymers, charac terized by elemental and infrared analysis, GPC, and wide-angle X-ray diffr action, had inherent viscosity from 0.3 to 0.7 dL/g, were obtained in yield s higher than 85%, show good solubility in various organic solvents, and ha d excellent thermal stability as shown by 10% weight loss temperatures in n itrogen and air (above 445 and 440 degreesC, respectively) and high glass t ransition temperatures (in the range of 188-226 degreesC). The introduction of two 1,3,4-oxadiazole units in the polymer repeat unit determines glass transition temperatures higher than those of similar polymers containing on ly one oxadiazole group in the repeat unit.