BLEND MEMBRANES FROM CELLULOSE KONJAC GLUCOMANNAN CUPRAMMONIUM SOLUTION

The blend membranes were prepared from cellulose/konjac glucomannan (K GM) cuprammonium solution by coagulating with aqueous 10 wt% NaOH solu tion, 20 degrees C and 40 degrees C water, respectively. Miscibility, pore morphology, structure, water permeability and mechanical properti es of the blend membranes were investigated. The complex forms of cell ulose/KGM in the mixed solutions, the effect of various coagulants and the percent content of KGM (w(KGM)). On the structure and properties of the blend membrane are discussed. SEM and mechanical relaxation ana lysis indicate that the blend membranes are miscible in the range of 0 -30 wt% of w(KGM). When w(KGM) was smaller than 20 wt%, the tensil str ength of the blend membrane coagulated by alkali aqueous solution was enhanced, corresponding to homogeneous structure and small pore size. However, blend membranes having a larger pore size (366 nm by SEM) and water permeability (560 ml/m(2) h mmHg) were obtained by coagulating the cellulose/KGM (70:30) cuprammonium solution with 40 degrees C wate r, where ca. 20% of KGM as pore former were removed from the membrane. (C) 1998 Elsevier Science B.V.