M. Brigodiot, E. Maréchal
1981
Citations
0
Influential Citations
7
Citations
Journal
Polymer Bulletin
Abstract
SummaryCations obtained by reaction of various protonic acids with 5-Methylenebicyclo [2.2.1] hept-2-ene (5-methylene-2-norbornene) have been studied by C NMR spectroscopy. The isomerization of initial carbocation has been pointed out. A correlation of these results with the structure of the corresponding polymers has been establishedThe cationic polymerization of 5-Methylenebicyclo [2.2.1] hept2-ene (5-methylene-2-norbornene) has been investigated several times and KENNEDY (1974) published a review on this topic. A structure of the polymer obtained by classical cationic initiation has been suggested; this results from infrared and X.R. diffraction studies.In a recent work IVIN et al. (1980) reported the13C NMR spectrum of a poly[5-methylenebicyclo [2.2.1] hept-2-ene] resulting from a Ziegler-Natta initiation. We obtained the same13C NMR spectrum as IVIN et al. when the initiator were TiCl4, CF3 COOH, CCl3COOH and concentrated H2SO4 (see fig.1). Chemical shifts and coupling constants $$J_{13_{C - H} } $$ fit with the generally accepted structure of the polymers: KENNEDY and MAKOWSKY (1967) suggested an isomerization of the active species: