Dilute Solution Properties of Styrene-N-Butyl Methacrylate (65:35) Copolymer: Short- and Long-Range Interaction of the Polymer Chain

Viscosity and light-scattering data on styrene-n-butyl methacrylate (65:35) in chloroform are presented and tested by the two-parameter theoretical relations. The short-range interactions K and A and the long-range interaction parameter B have been calculated by different equations, using intrinsic viscosity and second virial coefficient data. These are then compared to the values of the homopolymer polystyrene. The conformation or the steric factor for the polymer chain has also been calculated. The excluded volume parameter Z, which is related to both the short- and long-range parameters, has been evaluated along with the expansion factor α n . The higher value of the short-range parameters and the conformation factor compared to the parent styrene homopolymer is attributed to the effect of unlike monomer interactions causing extension of the polymer chain. An increase in the restriction of the internal rotation of side chains about the C-C bonds is also suggested. The excess interaction parameter has a negative value. The expansion factor α n has been related to the excluded volume factor Z and the coefficient C is in close agreement with the theoretically calculated value of Yamakawa and Tanaka.