| 摘要 |
<p>The invention describes a process which permits (1) the preparation of polymer solutions of sulfonated polymers in organic liquid having reasonably low viscosities (i.e., less than 20,000 cps), (2) the preparation of extremely viscous solutions or gels from such solutions by the simple process of mixing water with the polymer solution and (3) the reversion of such viscous solutions or gels to relatively low viscosity mixtures ? the reincorporation of polar cosolvents which are water immiscible at a desired stage. These operations are achieved by the use of the appropriate concentration of polymers having low concentrations of ionic groups present, preferably metal sulfonate groups. The novel process forms a polymeric solution or gel having a viscosity of at lease 50,000 cps and includes the steps of (a) forming a solvent system of an organic liquid and a polar cosolvent, the polar cosolvent being less than about 15 wt. % and the viscosity of the solution system being less than about 1,000 cps (b) dissolving a neutralized sulfonated polymer in the solvent system to form a solution, the concentration of the neutralized sulfonated polymer in the solution being 0.1 to 20 wt %, and the viscosity of the solution being less than 20,000 cps, and (c) adding 5 to 500 volume % water to the solution, the water being immiscible with the solution, with the polar cosolvent transferring from the solution to the water causing the viscosity of the solution or suspension to increase from less than 20,000 cps to greater than 50,000 cps.</p> |
