METHODS FOR PREPARATION OF ABSORBENT MICROSPHERICAL TANNIN RESIN

Tannin beads formed by reaction of Mimosa tannin (condensed-type tannin) with formaldehyde in nonpolar polybutenous medium were microspherical resins. Resins prepared with 37.5% tannin concentration were porous spherical resins with 139.22 m2/g of surface area (adsorption method of iodine in n -hexane, 2.1 m2/g for the dried beads by the Braunauer-Emett-Teller (BET) method) and were strong enough to withstand use on a column. The spherical resin adsorbed 3.7 mmol of Cr6+ ions per one gram dry weight of resin (by batch method), this adsorption being comparable to commercial adsorbent.