Hydrogen-bonded supramolecular poly(ether ketone)s

The preparation of 2,4-diamino-1,3,5-triazine telechelic poly(ether ketone)s (triazine PEKs) and the formation of supramolecular polymers with dodecyl-(alpha-omega)-bis(5-methyl-1,3-pyrimidine-2,4-dione) were investigated. Both structures interacted by complementing hydrogen-bonding units present at their respective chain ends, this being reminiscent of triple hydrogen bonding in DNA. The preparation of the triazine PEKs started from hydroxyl-terminated poly(ether ketone)s by a nucleophilic displacement reaction with 2,4-diamino-6-(4-fluorophenyl)-1,3,5-triazine. With this method and molecular weight control via the Carothers equation, a series of triazine PEKs with a complete degree of end-group functionalization were prepared. The structure of the polymers was proven by C-13 NMR spectroscopy and matrix-assisted laser desorption/ionization spectroscopy. When mixed as a 1:1 complex in solution with dodecyl-(alpha-omega)bis(5-methyl-1,3-pyrimidine-2,4-dione), short triazine PEKs (molecular weight = 5700 or 10,000) showed a temperature-dependent association behavior visible via dynamic NMR spectroscopy. Additional proof of the formation of a supramolecular, hydrogen-bonded network was derived from solid-state NMR spectroscopy, differential scanning calorimetry, and rheological investigations. (C) 2003 Wiley Periodicals, Inc.