CONFORMATIONAL PROPERTIES OF POLYVINYL BROMIDE) AND POLYVINYL FLUORIDE)

The conformational properties of molecules modeling poly(vinyl bromide) (PVB) and poly(vinyl fluoride) (PVF) dimers and trimers have been analyzed using the molecular mechanics method of R.H. Boyd et al., which takes into account both steric and electrostatic energies. The geometric and energy results show that the steric effects of changing the halide are greater than the electrostatic effects. Total conformational energies were used to determine a set of intramolecular interaction energies that by means of the rotational isomeric states model allowed estimation of the characteristic ratio, Cr, and dipole moment ratio, Cm, of PVB and PVF. The results agree satisfactorily with available experimental values.