Polycondensations of dimethyl phosphonate with diols: SEC and P-1 and C-13NMR spectroscopic studies

Polymeric phosphonate esters have a variety of potential applications. Thes e polymers can be prepared by the polycondensations of dimethyl phosphonate with certain diols. However, this method does not consistently yield high molecular weight polymers. NMR spectroscopy and size exclusion chromatograp hy studies demonstrate that low molecular weights result from methyl group transfer from a methyl phosphonate end group to an alcohol. The inactive ph osphonic acid end groups formed by this reaction can be converted into reac tive methyl phosphonate end groups by treatment with diazomethane. This all ows the preparation of polymers with number average molecular weights great er than 10(4) Da. (C) 2000 Elsevier Science Ltd. All rights reserved.