NMR-SPECTROSCOPY FOR THE STUDIES OF UNSAT URATED POLYESTERS INCORPORATING BICYCLO-[2,2,1]-HEPT-2-ENE FRAGMENTS

Quantitative analysis of the composition of unsaturated polyesters pro duced by condensation of maleic anhydride and anhydride of bicycle-[2, 2,1] -hept-2-ene-5,6-bicarboxylic acid with ethylene glycol and diethy lene glycol was performed by means of H-1 acid C-13 NMR. It was found that reversible thermal isomerization of the endo-form of the fragment of bicycle-[2,2,1]-hept-2-ene-5,6-bicarboxylic acid to exo-form occur s. The degree of fumaric-maleic isomerization and end-exo isomerizatio n were calculated. This degree of endo-exo isomerization was found to be virtually independent of the composition of polyester and of the in itial ratio of endo- and exo-forms of the anhydrides.