Hydroxy-telechelic polybutadiene microstructure and bulk polycondensation. Study by 1H and 13C NMR

The microstructure of an hydroxytelechelic polybutadiene (HTPB-A) and the bulk polycondensation with 4-4’ diphenyl methane diisocyanate (MDI) without chain extender have been studied by 1H and 13C NMR. Three main primary alcohols (H, G and V) have been observed and a few amount of epoxides. The reactivities of these three primary alcohols functions appeared to be different during the polycondensation. The appearance of gel in the medium was found to affect the conversions of the three hydroxyls, especially that of short branched chains (G).