Properties of cyclodextrins. III. Cyclodextrin-epichlorhydrin resins. Preparation and analysis

A bead polymn. process was used to prepare resins in a form useful for packing chromatographic columns from a-cyclodextrin (I) or b-cyclodextrin (II) and epichlorohydrin (III). A soln. of 2 ml. nonionic detergent (Nonidet P40) in 10 ml. o-xylene was added to 350 ml. o-xylene at 80 Deg , stirred 2 min., and mixed with a soln. prepd. by dissolving 9 g. finely powdered I in a mixt. of 5 g. water, 16 g. 30% NaOH, and 20 mg. NaBH4 at 30 Deg. After 5 min. vigorous stirring, 25 g. III was added. Beads formed in 30 min. The beads were then suspended in 100 ml. 1:1 vol. EtOH-water for 10 min., freed of excess liq., and suspended 30 min. in 96% EtOH. This procedure was repeated 2 times, and the beads were then dried 18 hrs. at 70 Deg. The bead polymn. of II was carried out similarly, using iso-BuCOMe instead of o-xylene solvent. Water-sol. resins were also prepd. by stirring the polymn. mixt. gently and omitting the surfactant. The apparent void concn. in the resins was detd. either by cleaving the a,1 -> 4 linkages by acid hydrolysis and then detg. the reducing groups liberated, or by utilizing the ability of cyclodextrin voids to form a sol. inclusion compd. with m-chlorobenzoic acid. The amt. of inclusion compd. was detd. spectrophotometrically and the apparent void concn. was read from a calibration curve. The results of degree of substitution calcns. indicated that the resins contained at least some polyoxyethene chains. [on SciFinder (R)]