DETERMINATION OF HANSEN SOLUBILITY PARAMETERS FOR SELECTED CELLULOSE ETHER DERIVATIVES

This paper describes a method for determining the partial solubility parameters of six Methocel and six Ethocel cellulose ether products. A simple computer spreadsheet has been devised to calculate the partial solubility parameters from the laboratory data. The cellulose ethers are characterized in terms of nonpolar, polar, and hydrogen-bonding behavior. Methocel A, E, F, K, and J all have similar solubilities and are thus assigned solubility parameters in the range of delta-d = 17.4-18.2, delta-p = 14.6-16.5, and delta-h = 15.5-19.4 in units of MPa1/2 and with a radius of interaction of 10.3. Methocel 311 has been assigned the values of delta-d = 17.1, delta-p = 9.8, delta-h = 13.2 MPa1/2 and a radius of interaction of 10.2. A very high methoxyl and hydroxypropyl substitution in the Methocel 311 product reduces the inherent polarity and hydrogen-bonding nature of the basic cellulose structure. Increased organic-like solubility is shown by the six Ethocel ethoxy ether cellulose derivatives. The range of Hansen partial solubility parameters are nonpolar (delta-d) = 16.6-17.3, polar (delta-p) = 6.6-8.3, and hydrogen bond (delta-h) = 8.5-10.0 MPa1/2.