ESTIMATION OF HANSEN SOLUBILITY PARAMETERS FOR (HYDROXYETHYL)-CELLULOSE AND (HYDROXYPROPYL)CELLULOSE THROUGH MOLECULAR SIMULATION

In this paper we examine the solubility properties of two broad famili es of cellulosic surfactants ((hydroxyethyl)- and (hydroxypropyl)cellu lose) using molecular models and molecular dynamics simulations. The c alculations were performed by building models of both the amorphous co ndensed state and the vacuum state. The condensed state models were co nstructed with single chain conformations in periodic cells with backb one torsion angles populated according to rotational isomeric states ( RIS) determined for the single chains. For HPC-253, a (hydroxypropyl)c ellulose for which experimental results have been published recently, we found good agreement between the simulations and experimental resul ts. Our simulations predict that the three-dimensional solubility para meters for this class of surfactants are dominated by the contribution s from polar and hydrogen bonding interactions. This result differs fr om the predictions of group additivity tables.