New polymer syntheses, 36. Functionalized aromatic polyethers derived from 4′‐substituted 2,6‐difluorobenzophenones

Abstract

Toluene, anisol, thioanisol, 4phenoxyacetophenone and N,N-diacetyl-Q-phenoxyaniline were subjected to a Friedel-Crafts acylation with 2,6-difluorobenzoyl chloride. The resulting 4'-substituted 2,6-difluorobenzophenones l ae were condensed with trimethyl silylated Bisphenol-A (2) to yield homopolyethers with pendant functional groups. A series of copolyethers was analogously prepared by cocondensation of 4I-substituted 2,6-difluorobenzophenones with a diphenol and 4,4 '-difluorobenzophenone (4a) or bis(4-fluorophenyl) sulfone (4 b), and another series by concondensation of 2 with mixtures of 4 '-substituted 2,ddifluorobenzophenones 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.

Preparation of Poly(arylene ether pyrimidine)s by Aromatic Nucleophilic Substitution Reactions

“…Previously, we reported polymerizations with bis-(trimethylsilyl) ethers and activated bis(aryl halide)s in the presence of a catalytic amount of cesium fluoride, resulting in high molecular weight poly(arylene ether isoxazole)s. 2,35 This synthetic approach to poly(arylene ether)s was originaly reported by Kricheldorf et al [39][40][41][42][43] without the formation of a potassium bis(phenolate) salt during the polymerization; this approach was also investigated for the preparation of poly(arylene ether pyrimidine)s. The lower nucleophilicity of the bis-(trimethylsilyl) ether moiety in comparison with the phenolate ion gives the added advantage of the use of comparatively higher reaction temperatures with lower risk of gelation due to cross-linking or the formation of exceedingly high molecular weight fractions.…”

Macrocycles 32. Syntheses of Cyclic Poly(Ether Ketone)s of Bisphenol-A

“…Regardless of whether 3a or 3b was used as reaction partner of silylated bisphenol-A, method II gave considerably better results than method I. Successful polycondensations of silylated diphenols with 2,6-difluorobenzophenones have been reported previously [32]. Yet, in agreement with a lower reactivity of 3a (or 3b) relative to 21 2 1 -DFBP, a higher temperature was needed (165 instead of 140 2 C) to obtain optimum results (no.5 1 no.6, table 3).…”

Rapid Synthesis of Hyperbranched Aromatic Polyetherimides

“…Krickeldorf has published a series of reports on the synthesis of polyetherketones and polyethersulfones using an arylation method involving trimethylsilyl (TMS) protected diphenols, activated difluorides, and catalytic amounts of CsF . Using a method similar to that reported by Kricheldorf, Bryant and St. Clair described the synthesis of linear polyetherimides derived from TMS-protected 3- and 4-hydroxyphenyl-4-fluorophthalimide AB monomers .…”