Hydrodynamic and Conformational Properties of Nitrile-Butadiene Rubbers in Ester Solutions

Dilute solutions of nitrile-butadiene rubbers in toluene, methyl acetate, ethyl acetate, and butyl acetate are studied by viscometry. The rubbers are obtained using paraffinate emulsifiers and contain the same amounts of acrylonitrile and different molecular weights. The effect of rubber molecular weight and solvent nature on the intrinsic viscosity [η], viscometric Huggins k ' and Kraemer k '' constants, the hydrodynamic volume of the macromolecule, and the root-mean-square end-to-end distance is estimated. Using these data, laws controlling changes in the thermodynamic quality of solvents with respect to nitrile-butadiene rubbers, which are confirmed by static light scattering measurements, are revealed.