ISSN:
0360-6376
Keywords:
Physics
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Alternating copolyamides of various ω-amino acids were synthesized by base-catalyzed polycondensation of N-isothiocyanatoacyl ω-amino acids in solution. Derivatives of the following amino acids were used: glycine, β-alanine, γ-aminobutyric acid, δ-aminovaleric acid, ε-aminocaproic acid, D,L-β-aminobutyric acid, trans-4-aminocyclohexane 1-carboxylic acid, 4-aminophenyl acetic acid, 3-aminobenzoic acid, 4-aminobenzoic acid, 3-amino-4-methyl benzoic acid, and 4-amino-3-methyl benzoic acid. The base-catalyzed polycondensation at lower temperatures gave purer products than the bulk condensation at 180-200°C. 13C-NMR and natural-abundance 15N-NMR spectra measured in trifluoroacetic acid demonstrate that in most cases undisturbed alternating sequences were obtained. Strong neighboring residue effects and long-range sequence effects were found in the 15N-NMR spectra, and structure/shift relationships are discussed. The sequences of copolyamides obtained by copolymerizations of lactams or β-amino acid N-carboxyanhydrides were investigated by both 15N-NMR and 13C-NMR spectroscopy. 13C-NMR spectroscopy was found to be more useful if the copolyamides consist of ω-amino acid units of different chain length. However, 15N-NMR spectroscopy is more suited if the monomer units differ exclusively by their substituents.
Additional Material:
8 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1982.170201006
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