POLY(ARYLENE ETHER AZOMETHINE)S - SYNTHESIS BY ALDIMINE-ACTIVATED NUCLEOPHILIC AROMATIC-SUBSTITUTION, CHARACTERIZATION, AND THIN-FILMS MORPHOLOGICAL-STUDY

A series of new, relatively high molecular weight poly(arylene ether a zomethine)s was prepared by condensation of silylated bisphenols with bis[N-(4-fluorobenzylideneaniline)] s (BFBAs) in polar aprotic solvent s in the presence of a catalytic amount of cesium fluoride. The polyme rization reaction was the formation of an aryl ether linkage by nucleo philic aromatic substitution. Studies of model compounds demonstrated the required electron withdrawal and the ability of the aldimine to ac tivate the fluoride in the ipso position towards the substitution reac tion. The resulting polymers were light yellow in color, had intrinsic viscosities between 0.31 and 0.42 dL g(-1), and could be solution cas t to form amorphous creasable thin films, with glass transition temper atures in the range of 147 to 208 degrees C. Several of the polymers b ecame partially crystalline on prolonged exposure to the solvent vapor , and the resulting morphologies were investigated by transmission ele ctron microscopy of ultra thin films. Thermogravimetric analysis studi es showed little thermal decomposition under nitrogen for temperatures up to 460-492 degrees C.