SYNTHESIS AND PROPERTIES OF HYDROGEL MEMBRANES BASED ON CHITOSAN AND SODIUM ALGINATE

摘要

Hydrogel membranes formed from polyelectrolyte complexes(PEC)obtained in the reactions of chitosan with sodium alginate(Scheme A)were investigated.The formation of complexes has been confirmed by FTIR method(Fig.1).So called state of water in the membranes of different total water content(W_c)was characterized by differential scanning calorimerry(DSC)(Fig.2 and 3).Three various types of water in the membranes were distinguished:free water,freezing water and non-freezing water.The contents of freezing(W_f)and non-freezing water(W_(nf))in the membranes of various W_c(Fig.5 and 6)as well as heat of fusion of freezing bound water(DELTA H_m)(Fig.4)were determined.The courses of DSC curves let come to the conclusions concerning microheterogenic structures of membranes formed from PEC investigated.It was found that molecular weight of chitosan very slightly influenced the state of water in the membranes tested.