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Loued, W., Wery, J., Dorlando, A. & Alimi, K. (2015) A combined study based on experimental analyses and theoretical calculations on properties of poly (lactic acid) under annealing treatment. J. Mol. Struct. 1081 486–493.
Added by: Laurent Cournède (2016-03-10 18:36:42) |
| Type de référence: Article DOI: 10.1016/j.molstruc.2014.10.010 Numéro d'identification (ISBN etc.): 0022-2860 Clé BibTeX: Loued2015 Voir tous les détails bibliographiques  |
Catégories: PMN Mots-clés: annealing, Atomic force microscopy (AFM), crystallization, DFT calculations, homo, ionic liquids, lumo analysis, nanocomposites, nbo analysis, optical-properties, Poly(lactic acid), polylactic acid, thermal-properties, X-ray diffraction (XRD) Créateurs: Alimi, Dorlando, Loued, Wery Collection: J. Mol. Struct. |
Consultations : 1/607
Indice de consultation : 4% Indice de popularité : 1% |
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In this paper, the significance of annealing, in two different atmospheres (air and vacuum), on the surface characteristics of poly (lactic acid) (PLA) films was investigated. X-ray diffraction (XRD) measurements correlated to atomic force microscopy (AFM) observations of the cast PLA films show that thermal treatment under air atmosphere is responsible for a significant increase of crystallinity with the increase of temperature. However, band gap energy of the title compound is slightly affected by annealing at different temperatures. As for the untreated PLA, the molecular geometry was optimized using density functional theory (DFT/B3LYP) method with 6-31g (d) basis set in ground state. From the optimized geometry, HOMO and LUMO energies and quantum chemical parameters were performed at B3LYP/6-31g (d). The theoretical results, applied to simulated optical spectra of the compound, were compared to the observed ones. On the basis of theoretical vibrational analyses, the thermodynamic properties were calculated at different temperatures, revealing the correlation between internal energy (U), enthalpy (H), entropy (S), Free energy (G) and temperatures. (C) 2014 Elsevier B.V. All rights reserved.
Added by: Laurent Cournède |