Synthesis and characterization of isomeric biphenyl-containing poly(aryl ether–bisketone)s. Part 1.—Polymers derived from 4,4′-(p-fluorobenzoyl)biphenyl and bisphenols

Abstract

A series of amorphous and semicrystalline poly(ary1 ether-bisketone)s have been synthesized from bisphenols and 4,4'-bis(p-fluorobenzoyl)biphenyl via nucleophilic aromatic substitution reactions. Model compound studies were carried out with a variety of substituted phenols, 4,4'-bis( p-fluorobenzoyl)biphenyl and 4,4'-bis( p-chloroben-zoy1)biphenyl. The bishalide monomers were synthesized by the reaction of biphenyl-4,4'-dicarboxylic acid with thionyl chloride followed by Friedel-Crafts acylation with the appropriate aryl halide. Potassium carbonate mediated reaction of these monomers in dimethylacetamide or diphenyl sulphone gave high-molecular-weight polymers in excellent yield. Polymers with semicrystalline morphologies were synthesized from soluble highmolecular-weight amorphous precursors with removable bulky substituents. Unlike the corresponding monoketone analogues, the amorphous poly(ary1 ether-bisketone)s exhibited poor solubility in a wide variety of solvents, indicative of improved solvent resistance. The glass-transition and melting temperatures of the polymers are among the highest known for poly(ary1 ether-ketone)s. In addition, the polymers exhibit excellent thermal stability and afford tough films by compression moulding.

Synthesis and Characterization of Isomeric Biphenyl Containing Poly(aryl ether-bisketone)s II. Polymers Derived from 3,3′-(4-Fluorobenzoyl)biphenyl and Bisphenols

“…This is in contrast to the significantly shorter times (8 to 10 h) needed for the completion of similar reactions of the same phenols with lla and llb. 20 These observations suggest the following. First, it is possible to use the bischloride, 15 polymers with bisphenol-A and 4,4'-dihydroxybiphenyl.…”

“…Polymer 10d was insoluble in all of the aforementioned solvents under reflux condition and exhibited 410 a high degree of crystallinity. 20 The poor solubility of the polymer 18e in these conventional solvent allowed for the measurement of intrinsic viscosity in concentrated aqueous sulfuric acid solution only. Although an intrinsic viscosity value of 0.46 dl g-1 was indicative of a moderately high molecular weight, only brittle film could be obtained upon compression molding.…”

“…This is in contrast to the high melting point (Tm= 470°C, first heating) observed for the corresponding polymer 10d derived from the linear 4,4' -isomer. 20 …”

“…The polymers have been characterized and the results from these studies have been compared with those of the corresponding polymers derived from 11 b. 20 …”

“…Recently, the synthesis and characterization of poly(aryl ether-bisketone)s, 10, derived from 4,4'-(4-fluorobenzoyl)biphenyl, llb, has been reported. 20 In this paper, we report the synthesis of bisketo functional monomers ( derived from 3,3' -biphenyldicarboxylic acid), related model compound studies and polymers based upon isopropylidenebiphenol (bisphenol-A), hydroquinone, 4,4' -dihydroxy biphenyl (biphenol), 4,4' -dihydroxy diphenylsulfone (bisphenol-S) and 4,4' -dihydroxybenzophenone. The polymers have been characterized and the results from these studies have been compared with those of the corresponding polymers derived from 11 b.…”