Toluene, anisol, thioanisol, 4‐phenoxyacetophenone and N , N ‐diacetyl‐4‐phenoxyaniline were subjected to a Friedel‐Crafts acylation with 2,6‐difluorobenzoyl chloride. The resulting 4′‐substituted 2,6‐difluorobenzophenones 1a – e were condensed with trimethyl silylated Bis‐phenol‐A ( 2 ) to yield homopolyethers with pendant functional groups. A series of copolyethers was analogously prepared by concondensation of 4′‐substituted 2,6‐difluorobenzophenones with a diphenol and 4,4′‐difluorobenzophenone ( 4a ) or bis(4‐fluorophenyl) sulfone ( 4b ), and another series by cocondensation of 2 with mixtures of 4′‐substituted 2,6‐difluorobenzophenones and 2,6‐difluorobenzonitrile ( 8 ) or 2,6‐difluoropyridine ( 9 ). All polyethers were characterized by inherent viscosities, elemental analyses and DSC‐measurements. In individual cases GPC‐measurements, thermomechanical and thermogravimetric analyses were conducted. The quantitative polymer‐analogous oxidation of methylthio groups into methylsulfinyl and finally into methylsulfonyl groups is demonstrated.
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Kricheldorf et al. (1989) studied this question.
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