End-group analysis of poly(phenyl glycidyl ether), 3. Isopropoxy and chlorine groups using 1H and 13C nuclear magnetic resonance (original) (raw)

1995, Macromolecular Chemistry and Physics

The hydroxylic end-groups in the soluble fraction of poly(pheny1 glycidyl ether) (PPGE) obtained with the aluminium isopropoxide (AIP)/ZnCl, initiator system are studied using nuclear magnetic resonance spectroscopy (NMR). To achieve complete assignment, model compounds are synthesized and their carbamate and trifluoroacetate derivatives obtained from trichloroacetyl isocyanate (TAI) and trifluoroacetic anhydride (TFAA) are prepared. These derivatizating reagents allow primary and secondary alcohols to be distinguished, since upfield or downfield shifts are produced, and at the same time they have the potential of separating overlapping peaks. Several PPGEs with different degrees of regularity are also synthesized using various initiator systems. Thus, it is possible to identify the carbon signals of both final hydroxylic groups and their adjacent units, and the presence of two types of unit linked to secondary hydroxylic end-groups is demonstrated. Likewise, in the soluble fraction prepared with AIP/ZnCl, the absence of the irregular units linked to secondary hydroxylic end-group is demonstrated, so proving the high regularity of this fraction.