Sodium Hydroxide → Divinylbenzene-styrene

Participants

Reaction Conditions

Reaction Steps

This example illustrates the hydrolysis and resuspension of the methylacrylate-divinylbenzene copolymer of Example 7 to produce a weak-acid-functionalized ion exchange resin emulsion. A 200-g sample of the emulsion produced in Example 7 is added to a stirred solution of 57.4 g of 50% aqueous sodium hydroxide solution in 250 ml of water--this represents a 20% excess of base--and the emulsion is observed to coagulate. This mixture is heated to 93° C., held at that temperature for 2 hours, and cooled to room temperature. The coagulum is observed to re-suspend in the sodium hydroxide solution during the stirring and heating period. The emulsion product is diluted to 800-850 ml with water and is passed through a column of Amberlite IR-120 cation exchange resin (trademark of Rohm and Haas Company, Philadelphia, Pa., for a sulfonic acid functionalized, styrene/divinylbenzene gel cation exchange bead resin) in the H+ form to remove the excess sodium hydroxide and convert the product to the free acid form. The solids content of the resulting emulsion is 4.74%, and the weak acid cation exchange capacity is 9.4 meq/g of dry polymer.

Provenance & Evidence