CHARACTERIZATION OF FUNCTIONAL ALIPHATIC OLIGOAMIDES USING N-TRIFLUOROACETYLATION - I - NMR ANALYSIS

The H-1- and C-13-NMR analysis of functional oligoamides was carried o ut after they had been modified by trifluoroacetic anhydride derivatiz ation, leading to chloroform-soluble oligomers. The spectra of oligoam ides-6, -11, -12, -6,6 and -6,10 were compared. The influence of the m ethylene group number on the CO amide chemical shift was studied by C- 13-NMR. The coupling constants J(C-F) and J(C-C-F) were also determine d. Monomers, chain limiters and macromolecular structures were charact erized and quantified from the H-1- and C-13-NMR spectral analysis. Th e number-average molar masses were also calculated from integration of the spectra and were compared with values obtained by end group chemi cal titration. (C) 1998 Elsevier Science Ltd. All rights reserved.