The dilute solution of polystyrene (I) with narrow mol. wt. distribution and mol. wt. 1 ?104 to 18.9 ?106 in butanone at 20?was studied by light scattering, velocity sedimentation, and viscometry. The results were compared with the literature data of I in theta and good solvents. The unperturbed dimension, the interaction parameter, and the binary cluster integral values estimated based on Burchard-Stockmayer-Fixman-Yamakawa equation (1970) and on Baumann equation (1965) agreed well with the literature data.

Key words: SOLVENTS, POLYSTYRENE, POLYMER SOLUTION, BUTANONE, LIGHT SCATTERING TEST, VISCOMETRY, THERMODYNAMIC STATES, SETTLING