Transport properties of chitosan membranes: Influence of crosslinking

A chitosan film with acetylation degree close to 2% was crosslinked with gl utaraldehyde. The consequences of this chemical modification were studied o n the polymer gas and water transport properties. The crystalline domains w ere not affected by the crosslinking reaction and the modification of the a morphous phase did not induce variation of the gas permeability at anhydrou s state. A crosslinking of 5 h, leading to a theoretical amine conversion o f 60% in the amorphous phase induced only small changes of the polymer wate r sorption capacity at relative pressures less than 0.5. The main modificat ion of the transport properties induced by this treatment occurred at a rel ative pressure equal to one with a significant reduction of the water sorpt ion and water permeation and with the impossibility to measure the gas perm eability coefficient in these conditions due to the brittleness of the memb rane. (C) 2000 John Wiley & Sons, Inc.