Competing processes for poly(aryl ether‐ketone) synthesis, 3. Polymerization reactions of 1,3‐bis(4‐chlorobenzoyl)benzene and 1,3‐bis(4‐fluorobenzoyl)benzene in N‐methyl‐2‐pyrrolidinone

Abstract

AbstractThe effects of N‐methyl‐2‐pyrrolidinone (NMP) as solvent on the polymerization reactions of 1,3‐bis(4‐chlorobenzoyl)benzene (1,3‐CBB) and 1,3‐bis(4‐fluorobenzoyl)benzene (1,3‐FBB) with 4,4′‐isopropylidenediphenol (bisphenol‐A) were examined. The failure of these reactions to produce high molecular weight polymers in the presence of anhydrous potassium carbonate is due to dehalogenation of 1,3‐CBB via substitution radical‐nucleophilic unimolecular (SRN1) processes. On the other hand, 1,3‐FBB undergoes nucleophilic aromatic substitution reactions (SNAR) with the carbonate anion at elevated temperatures. However, it is possible to synthesize high molecular weight polymers from 1,3‐FBB and bisphenol‐A in NMP either by first forming the bisphenoxide with stoichiometric amounts of aqueous sodium hydroxide or in the presence of anhydrous potassium carbonate at a lower reaction temperature.