EFFECT OF TEMPERATURE AND SOLVENT COMPOSITION ON THE UNPERTURBED DIMENSIONS OF POLYSTYRENE

Several procedures have been used to establish and verify the unperturbed state of polystyrene in 1-chlorodecane (θ = 6.2° C) and 3-methyl cyclohexanol (θ = 98.4° C) as well as in other single solvents having 6.2° < θ < 98.4°. At each θ-temperature for a single solvent, the unperturbed state for a binary solvent was established in mixtures of 1-chlorodecane and 3-methyl cyclohexanol of varying composition. Viscometric measurements showed that neither the nature of the solvent nor the temperature affects the unperturbed chain dimensions appreciably. On the other hand, the unperturbed mean square radius of gyration measured directly by light scattering exhibits a definite decrease with increase in temperature, which accords qualitatively with the conformational energy calculations of Flory and co-workers. © 1979.