New copolymers based on renewable PBF/PEGF are tailored to show advantageous processing features as compared to PBF (enlarged working temperatures and no crystallisation at slow rates).

Two samples of poly(vinyl bromide) were prepared and purified. Sample A was synthesized by radical polymerization of vinyl bromide at 35 °C, and sample B was obtained by extraction of sample A with dioxane at room temperature. Both samples had an isotactic content (determined by 13C NMR) of 46%. Molecular weight averages were calculated from viscometric measurements in THF solutions and were found to be 52100 and 27400 for samples A and B, respectively. Dielectric measurements were performed in solutions of both samples in dioxane and 1-methylnaphthalene at several temperatures, and dipole ratios Dx = (µ2) /xm2 were found to be 0.53 and 0.45 in dioxane and 1-methylnaphthalene, respectively. No noticeable dependence of Dx with molecular weight was found; the variation of Dx with temperature was too small to allow an accurate determination of its temperature coefficient. A rotational isomeric state model was derived and used to calculate dipole and characteristic (C" = (r2)0/nP) ratios. Theoretical values of both D" and C" are in good agreement with experimental results.