Poly(arylene ether azomethine)s: Synthesis by aldimine-activated nucleophilic aromatic substitution, characterization, and thin films morphological study

摘要

A series of new, relatively high molecular weight poly(arylene ether azomethine)s was prepared by condensation of silylated bisphenols with bis[N-(4-fluorobenzylideneaniline)] s (BFBAs) in polar aprotic solvents in the presence of a catalytic amount of cesium fluoride. The polymerization reaction was the formation of an aryl ether linkage by nucleophilic aromatic substitution. Studies of model compounds demonstrated the required electron withdrawal and the ability of the aldimine to activate the fluoride in the ipso position towards the substitution reaction. The resulting polymers were light yellow in color, had intrinsic viscosities between 0.31 and 0.42 dL g(-1), and could be solution cast to form amorphous creasable thin films, with glass transition temperatures in the range of 147 to 208 degrees C. Several of the polymers became partially crystalline on prolonged exposure to the solvent vapor, and the resulting morphologies were investigated by transmission electron microscopy of ultra thin films. Thermogravimetric analysis studies showed little thermal decomposition under nitrogen for temperatures up to 460-492 degrees C. [References: 22]