1964 年 84 巻 5 号 p. 440-444
The volume fractions of each component in the dilute phase (υ1′, υ2′, υ3′) and in the concentrated phase (υ1″, υ2″, υ3″) were calculated according to Flory's and Scott's theoretical equations, in the ternary system of solvent-1, nonsolvent-2, and polymer-3. These values at the plait point were also calculated, (υ1)pl, (υ2)pl, (υ3)pl. In these treatments it was assumed that P1=P2=1, P3>>1 for the polymerization degree Pi; and A=0, B=0, C≠0 for the interaction parameters.
From these calculations, relation between the initial concentration of polymer (υ3)° and the swelling ratio of the precipitated polymer 1/υ3″ were calculated as functions of the relative volume of nonsolvent added to the system (V/V0). Relation between the relative volume of nonsolvent added to the system (V/V0)pl before the precipitation starts and the polymerization degree P were also calculated for various values of parameter C.
From these results it became evident that the fractionation effect will be good when the dilute polymer solution and nonsolvent of small interaction parameter C are used. Theoretical solubility limit equation was obtained of polymers of various polymerization degree.