DRYING OF ACIDIC MACROPOROUS STYRENE-DIVINYLBENZENE RESINS

Drying of the acidic macroporous resin Lewatit K 2631 has been studied. Oven drying at 84-112-degrees-C and 0.015 atm water partial pressure shows that the resin behaves as a fibrous solid. Drying by methanol percolation at 20-degrees-C leads to moisture contents in the resin slighty lower than in the previous method. Finally, oven drying of the resin previously washed with methanol shows that the residual water content increases with increasing amounts of the methanol. Estimates of the water-effective diffusivity suggest that the last method gives rise to a lower polymer shrinkage. The changes in the polymer morphology probably result from the formation of a large number of small pores.