Résumé
This study presents newer insights on the dehydrofluorination of poly(vinylidene fluoride), PVDF, in alcoholic sodium hydroxide using infrared (IR), Raman and nuclear magnetic resonance (1H and 1H {19F}) spectroscopies. Details on the reactivity of phases and site selectivity of different orientations viz head-to-tail and tail-to-tail is comprehensively examined using IR/Raman and NMR (1D and 2D), respectively. The alpha-phase is prominently involved in dehydrofluorination and transforms into the more electroactive beta-phase. 1H NMR spectra highlight that the tail-to-tail addition of PVDF is not disturbed and remains unaffected during dehydrofluorination reaction. Furthermore, 1H -19F heteronuclear correlation spectroscopy (Hetero COSY) clearly evidences the formation of the -(CH=CF)- double bond in dehydrofluorinated PVDF. Moreover, detailed mechanistic insights of dehydrofluorination reaction and possible internal crosslinking during the chemical transformation is presented.