NEW POLYMER SYNTHESES .71. AROMATIC POLYETHERS WITH ESTER GROUPS IN THE BACKBONE

Aromatic poly(ether-ester)s were prepared by two procedures. First, po lycondensation of activated difluoroaromatics (such as 4,4'-difluorodi phenylsulphone, 2,6-difluorobenzonitrile or 2,6-difluoropyridine) was performed with a silylated reaction partner in bulk at temperatures up to 320-degrees. Second, polycondensation of the same reactants was do ne in N-methylpyrrolidone-3 at 180-degrees. Three kinds of silylated m onomers were used, viz. hydroquinone 4-hydroxybenzoate, 6-hydroxy-2-na phthoic acid, and several dicarboxylic acids. All attempted polyconden sations with silylated dicarboxylic acids failed. The highest yields a nd molecular weights (M(w)BAR up to 10(5)) were obtained by polyconden sations of silylated hydroquinone 4-hydroxybenzoate in bulk.