Experimental (IR/Raman and 1 H/ 13 C NMR) and Theoretical (DFT) Studies of the Preferential Conformations Adopted by l -Lactic Acid Oligomers and Poly( l -lactic acid) Homopolymer
2011; American Chemical Society; Volume: 116; Issue: 1 Linguagem: Inglês
10.1021/jp205033c
ISSN1520-6106
AutoresS. Jarmelo, Dina S. Marques, Pedro Simões, Rui A. Carvalho, Cecília Batista, C. Araujo-Andrade, M.H. Gil, Rui Fausto,
Tópico(s)Carbon dioxide utilization in catalysis
ResumoL-Lactic acid (L-LA) oligomers (up to the pentamer) were studied by three complementary approaches: vibrational (IR and Raman) and NMR ((1)H and (13)C) spectroscopies and DFT calculations. Vibrational and NMR spectra of L-LA oligomers and poly(L-lactic acid) (PLLA) homopolymer were recorded at room temperature and interpreted. Further insight into the structures (conformations) of the title systems was provided by theoretical B3LYP/6-311++G(d,p) studies. Calculated energies and computed vibrational and NMR spectra of the most stable conformers of L-LA oligomers, together with the experimental vibrational and NMR spectra, enabled the characterization of the preferred conformations adopted by PLLA chains.
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