CONFORMATION AND POLARIZATION FOR MONODIS PERSE OLIGOMERS AND POLYMERS OF POLY(ARYL ETHER KETONE)S IN SOLUTION

By means of ab initio method the dihedral angle of 44 degrees for 4,4' -difluorobenzophenone and of 51 degrees for MES(3) are obtained. UV sp ectra from monodisperse oligomers and their molecular polarization in H2SO4 show that the protonation of H2SO4 acting on carbonyl group is o ne of the major factors of-the polarization. The protonation produces a new absorption peak at lambda = 400 nm or so(UV); Meanwhile, the ove rlapping of planar conformation from polarization produces another new absorption peak at lambda = 500 nm. Based on the protonation model, t he configuration interaction (CI) calculation on it is made, the resul ts of which are in good agreement with those from experiment. All thes e prove that the absorption peak at lambda = 400 nm for poly(aryl ethe r ketone)s is resulted from carbonyl polarization. Thus, the polymer m olecular weight measured in H2SO4 should be corrected according to ket one content in the main chain.