Poly(vinyl alcohol) (PVA) can be dissolved in a nonaqueous medium in the presence of catalytic concentration of ethyl nitrate dimethyl sulfoxide, C2H5ONO2. DMSO. From the PVA solution, poly(vinyl propionate), PVPR was prepared by the homogeneous esterification of PVA with propionic acid. The ester thus formed contained some unconverted hydroxyl group. The formation of the ester was confirmed by the IR and H-1-NMR spectra. The molecular weight of the ester was determined by GPC and intrinsic viscosity (eta) was determined by viscometric method. Glass transition temperature, T-g, was obtained from differential scanning calorimetric (DSC) analysis. Thermal stabilities of the ester were checked by thermogravimetric analysis (TGA) and differential thermogravimetric (DTG) analysis. The efficiency of the ester as a flow improver of crude oil was also examined. (c) 2006 Wiley Periodicals, Inc.