Conformational analysis of cellulose acetate in the dense amorphous state
- 507 Downloads
Atomistic simulations of cellulose acetates (CAs) differing in their degree of substitution have been performed and analyzed in terms of conformation and interaction schemes. The stabilization of the structure of these cellulose derivatives is understood as a subtle balance between hydrogen bonds and the dipolar acetate-acetate interactions that are associated with important changes in the macromolecular conformation. On the one hand, cellulose and cellulose triacetate (CTA) are characterized by a single stabilization process (H-bonds and dipolar interactions respectively), showing a similar structure in their melt phase together with similar radii of gyration. On the other hand partially acetylated CAs combine both the conformational properties of cellulose and CTA but present an unexpected conformational domain, named C2, which induces a local hydrophobic pocket. These CAs are also further stabilized by hydrogen bonds between the hydroxyl and acetyl groups. Although idealized, the proposed models are realistic since they are in good agreement with literature experimental results.
KeywordsCellulose Cellulose acetate Amorphous Conformation Dipole interaction Hydrogen bonds
The authors want to acknowledge fruitful discussions with D. Long (LPMA, Lyon), A. Fabre and P-Y. Lahary (Solvay Lyon) and L. Heux, Y. Nishiyama and H. Chanzy (CERMAV). Support from the IT teams of Solvay was highly appreciated for the organization of simulations.
- Bel’nikevich NG, Bolotnikova LS, Kramarenko LN, Naimark NI, Khripunov AK, Frenkel SY (1978) Spontaneous elongation of cellulose esters in water-phenol media. Vysokomol Soedin, Ser B 20:37–38Google Scholar
- Elidrissi A, El Barkany S, Amhamdi H, Maaroufi A, Hammouti B (2012) New approach to predict the solubility of polymers application: cellulose acetate at various DS, prepared from Alfa “Stipa-tenacissima” of Eastern Morocco. J Mater Environ Sci 3:270–285Google Scholar
- Ernst A, Vasella A (1996) Oligosaccharide analogs of polysaccharides. Part 8. Orthogonally protected cellobiose-derived dialkynes. A convenient method for the regioselective bromo- and protodegermylation of trimethylgermyl- and trimethylsilyl-protected dialkynes. Helv Chim Acta 79:1279–1294CrossRefGoogle Scholar
- Kamide K (2005) Cellulose and cellulose derivatives. Molecular characterization and its applications. Elsevier, AmsterdamGoogle Scholar
- Lindahl E, Hess B, van der Spoel D (2001) GROMACS 3.0: a package for molecular simulation and trajectory analysis. J Mol Model 7:306–317Google Scholar
- Mason PE, Neilson GW, Enderby JE, Saboungi M-L, Cuello G, Brady JW (2006) Neutron diffraction and simulation studies of the exocyclic hydroxymethyl conformation of glucose. J Chem Phys 125:224505/1–224505/9Google Scholar
- Misra M, Seydibeyoglu O, Ray D, Das K, Mohanty A (2011) Biodegradable nanocomposites from cellulosic plastics and cellulosic fiber. Monogr Phys Chem Mater 68:123–165Google Scholar
- Perez S, Brisse F (1977) The crystal and molecular structure of a trisaccharide, β-cellotriose undecaacetate: 1,2,3,6-tetra-O-acetyl-4-O-[2,3,6-tri-O-acetyl-4-O-(2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl)-β-D-glucopyranosyl]-β-D-glucopyranose. Acta Crystallogr, Sect B B33:2578–2584CrossRefGoogle Scholar
- Sato H, Suttiwijitpukdee N, Hashimoto T, Ozaki Y (2012) Simultaneous synchrotron SAXS/WAXD study of composition fluctuations, cold-crystallization, and melting in biodegradable polymer blends of cellulose acetate butyrate and poly(3-hydroxybutyrate). Macromolecules 45:2783–2795CrossRefGoogle Scholar