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

- The thermally stable BPPP successfully initiated VDF polymerization.
- Only CF3CF2CF2OCF(CF3·) radicals initiate the polymerization of VDF.
- The Tg of PPVE was calculated to be −10.3 °C using the Flory-Fox equation.
- BPPP initiated PVDF had higher thermal stability than commercial PVDF.

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 (rVDF ∼ 1.06, rPPVE ∼ 0). The Tg of poly(PPVE) (−10.3 °C) was determined using the Tgs 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.

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