NYLON 4/PVA BLEND MEMBRANE FOR DIALYSIS

To improve the hydrophilicity and enhance the transport flux of nylon 4 membrane for dialysis, this study attempts to utilize blending nylon 4 with poly (vinyl alcohol) (PVA). The instability of PVA in water can be significantly improved by esterification of PVA with formic acid when it is used as casting solvent of PVA/nylon 4 blend membrane. By this method, the stability of PVA in water can be obtained more easily than by other methods, such as chemical, gamma-ray irradiated crosslinking, or high-temperature treatment used by previous researchers. The effects of maturation time of the casting solution, nylon 4/PVA ratios, and casting solvent compositions on esterification of PVA, salt permeability, water content, partition coefficient, diffusivity, and mechanical strength of membranes are studied. The membrane, prepared by casting solution of nylon 4/PVA = 9/1 wt % formic acid with 24-h maturation time, possesses permeabilities of NaCl and urea, 33.14 and 19.67 X 10(-5) cm2/min, respectively.