MOLECULAR-STRUCTURE AND POLARIZATION FOR MODEL COMPOUNDS OF POLY(ARYLETHER KETONE)

This paper studied the structure and polarization of model compounds o f poly(aryl ether ketone) in solution of H2SO4 and CDCl3 or CDCl3 + DM SO-d(6). Results show that these compounds are greatly polarized in H2 SO4,that is, their carbonyl carbons have shorter spin lattice relaxati on time (T-1) and greater chemical shifts while their quaternary carbo ns connected to the carbonyl group have short T-1 but smaller chemical shifts. This polarization produces new maximum absorption at about 40 0nm(lambda(max) in UV spectrum). The average dihedral angle of these m odel compounds relative to the molecular Zig - Zag plane are 36 degree s to 39 degrees,based on which the Mulliken charges of different polar ization models are calculated. All of these support the polarization m echanism that the bridge - bonds are protonated and/or effected by dip ole - dipole interaction of H2SO4, which unlocalizes the charges on ar yl - rings.