The reaction of cellulose with succinic anhydride in nonaqueous methanesulfonic acid under hetero-or homo-geneous conditions at 25 "C was studied. Homogeneous reaction conditions minimized the formation of crosslinking diester linkages, but during the initial period of heterogeneous succinoylation, topochemically restricted reactions generated crosslinked cellulose derivatives which were not soluble in dilute alkali.
Regenerated cellulose and chitosan membranes were studied for the pervaporation separation of an aqueous solution of urine component (ammonia, uric acid or creatinine). The permeation rate of water increased with increase of the temperature of feed solution induced into the upstream side of membrane module. Uric acid, creatine and creatinine were not found in the permeate through the all membranes investigated. Selective permeation of water and ammonia depends on membrane. The removal of ammonia through the chitosan membrane was from 57% to 59%. Adsorption of ammonia from the downstream vapor by silica gels was carried out. And desorption of ammonia from the adsorbents by heating under the reduced pressure to regenerate the capacity of adsorption was also confirmed. In the case of new pervaporation system, the combination of pervaporation and adsorption/desorption process, ammonia was almost completely removed, and finally the pure condensed water was obtained in the cold trap.
Chitosan was precipitated onto wood pulp, glass and polypropylene fibers suitable for papermaking. The coating which formed on the fibers was characterized by photomicrography after the formation of colored derivatives, and by scanning electron microscopy. The most uniform and adherent coatings were formed on the wood pulp fibers and the least were formed on the polypropylene fibers. Paper handsheets were readily formed from the chitosan-coated wood pulp and glass fibers, but not from the chitosan-coated polypropylene fibers.
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