Bis(perfluoro-2-n-propoxyethyl)diacyl peroxide initiated homopolymerization of vinylidene fluoride (VDF) and copolymerization with perfluoro-n-propylvinylether (PPVE)

Vinylidenefluoride (VDF) has been homopolymerized and copolymerized with perfluoro-n-propylvinylether (PPVE) using bis(perfluoro-2-n-propoxyethyl)diacyl peroxide (BPPP) as the initiator in CF₂ClCFCl₂. The polymers obtained were characterized with ¹⁹F NMR and ¹H NMR spectroscopy, DSC and TGA. The ¹⁹F NMR spectra were used to determine the polymer microstructures and end groups. Both PVDF and poly(VDF–PPVE) were terminated on both chain ends by CF₃CF₂CF₂OCF(CF₃)∼ arising from the decomposition of the initiator. The concentration of end groups was used to assess the molecular weight of the polymers. Using the Fine–Ross method, the reactivity ratios of both monomers were determined (r_VDF ∼ 1.06, r_PPVE ∼ 0). The T_g of poly(PPVE) (−10.3 °C) was determined using the T_gs of VDF/PPVE copolymers with different compositions and the Flory–Fox equation. A new method to produce a modified PVDF or VDF copolymer for powder coatings with higher thermal stability was also developed.