Molecular simulations of the effects of substitutions on the dissolution properties of amorphous cellulose acetate

The dissolution behavior of cellulose acetate (CA) is an extremely important property in its extensive applications and preparation of derivatives. In this paper, we proposed a molecular model building strategy to construct amorphous CA with various substituent distributions (different degrees of substitution and substitution posi-tions). A protocol combing molecular dynamics simulation and density functional theory (DFT) was applied to systematically investigate the dissolution behavior of CAs, and the structural properties of CAs. The reduced cohesive energy and polarity of CAs caused by the increase in substituents would enhance its solubility. The interaction of solvent molecules and CAs and the diffusion of solvent molecules in CAs have a synergistic effect on the dissolution of CAs. The diffusion coefficient is the primary factor affecting the solubility. Moreover, substituents at different positions of the anhydroglucose units along the CAs chains would produce different steric hindrance effects, which in turn affect the dissolution behavior.

Automated summary

The dissolution behavior of cellulose acetate (CA) is a critical property for its wide range of applications and derivative preparations. This study proposes a molecular model building strategy to investigate the dissolution behavior and structural properties of CA using molecular dynamics simulation and density functional theory. The findings suggest that an increase in substituents reduces the cohesive energy and polarity of CA, thereby enhancing its solubility. The interaction of solvent molecules and the diffusion coefficient also play a synergistic role in CA dissolution.