Facile synthesis and characterization of hyperbranched poly(aryl ether ketone)s obtained via an A2 + BB′2 approach

A fast and highly efficient approach for the synthesis of hyperbranched poly(aryl ether ketone)s (HPAEKs) via the polycondensation of A(2) and BB'(2) monomers is described. Commercially available hydroquinone (HQ, A(2) monomer) and easily synthesized 2,4',6-trifluorobenzophenone (TF, BB'(2) monomer) were thermally polycondensed to prepared fluoro- or phenolic-terminated HPAEKs with K2CO3 and Na2CO3 as catalysts. During the reaction, the fluorine at the 4'-position of TF reacts rapidly with the phenolic group of HQ, forming predominantly dimers and some other species. The dimer can be considered as a new AB'(2) monomer. Further reactions among molecules AB'(2) and AB'(2) with some other species result in the formation of HPAEKs. Fourier transform infrared and H-1 NMR spectra revealed the structures of the resultant polymers. The degree of branching (DB) of the fluoro-terminated hyperbranched polymers was determined to be in the range 50-57% from 1H NMR spectra, whereas the DB of the phenolic-terminated hyperbranched polymers was determined to be 100%. These hyperbranched polymers exhibit excellent solubility in general organic solvents and possess moderate molecular weights with broad distributions determined using gel permeation chromatography. Moreover, the structure and performance of the HPAEKs can be conveniently regulated by adjusting the type and feed ratio of the two monomers. (C) 2010 Society of Chemical Industry