HYDROXY-TELECHELIC POLYBUTADIENE MICROSTRUCTURE AND BULK POLYCONDENSATION - STUDY BY H-1 AND C-13 NMR

The microstructure of an hydroxytelechelic polybutadiene (HTPB-A) and the bulk polycondensation with 4-4' diphenyl methane disocyanate (MDI) without chain extender have been studied by H-1 and C-13 NMR. Three m ain primary alcohols (H, G and V) have been observed and a few amount of epoxides. The reactivities of these three primary alcohols function s 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).