Conformation and packing of poly(alkylene phosphate) chains in the crystallattice. Part II: Temperature FTIR studies

The infra-red absorption of recrystallized samples of the polyhexa-, polyhe pta-, polyocta-, polynona-, polydeca- and polydodecamethylenephosphate was measured during the heating, from the room temperature to the temperature h igher than the melting temperature of the polymer examined. The heating ind uced changes of FTIR spectra proved, that the spatially arranged polyphosph ate chains are cross-linked by the P = O ... H-O hydrogen bonds, whose prop erties consist with the properties of the theoretically predicted hydrogen bonds. Moreover, the strong crystal field splitting of the rocking vibratio ns of the polyphosphate monomer unit methylene chain and of the (P)- O-C st retching vibrations has been observed. As was founded, the dispersion curve s of rocking vibrations of the polyphosphate chain (CH2)(n) trans sequences may be approximated by the exponential function: nu = nu(infinity) exp (C/ n). The crystal field splitting effects proved, that the unit cell of polyp hosphate crystals contain two polyphosphate monomer unit, and that the conf ormation of the polyphosphate extended chains is close to the conformation of the modeled polyphosphate extended chains. (C) 2000 Elsevier Science B.V . All rights reserved.