PREPARATION OF POLY(VINYL ALCOHOL) PARTIC LE-IMMOBILIZED TANNINS

The immobilization of tannins with poly(vinyl alcohol) (PVA) particles was investigated. The immobilization procedure can easily be performe d by immersing PVA particles in an aqueous solution containing tannins . The tannin molecules were immobilized onto the surface and/or the po res of the polymer particles through hydrogen bonding. The amount of i mmobilized tannins, 0.5 similar to 0.7 g/g (dry polymer), increased as the pH of the tannin aqueous solution became lower. The release of ta nnins was observed when the particles with immobilized tannins were so aked in water for a long time. However, the release can be controlled by treating the particles with a glutaraldehyde aqueous solution.