Thermodynamics/hydrodynamics of aqueous polymer solutions and dynamic mechanical characterization of solid films of chitosan, sodium alginate, guar gum, hydroxy ethyl cellulose and hydroxypropyl methylcellulose at different temperatures

Experimental densities and viscosities of five important carbohydrate polymers viz. chitosan, sodium alginate, guar gum, hydroxy ethyl cellulose and hydroxypropyl methylcellulose have been measured in aqueous media at five different temperatures and at nine weight fractions. Using the density data, excess molar volumes have been computed. Mathematical equations are proposed to calculate the activity, which agreed well with the experimental data. Viscosity data at different concentrations of carbohydrate polymer solutions have been used to calculate the viscosity average molecular weight of the polymers. Thin free standing films of these polymers have been prepared by solution casting method and were tested for dynamic mechanical behavior as well as glass transition of the polymers were evaluated by dynamic mechanical testing analyzer and thermogravimetry, respectively.