THE EFFECT OF HYDROPHILIZATION OF POLYPROPYLENE MEMBRANES WITH ALCOHOLS ON THEIR TRANSPORT-PROPERTIES

The effect of alcohol alkyl chain length on hydrophobic character of p olypropylene (PP) membranes has been studied. The polypropylene membra nes hydrophilized with methyl, ethyl, n-propyl and n-butyl alcohol wer e used in the studies. The studies were carried out by the impedance m ethod and the changes in transport properties of the studied membranes at various hydrophilizing agent concen-trations were estimated. The p olypropylene membranes were found to be firmly hydrophilized with meth yl, ethyl and n-propyl alcohol at about 31% by weight and with n-butyl alcohol at about 40% (wt) and that the effect is absent at lower conc entrations. It was shown that the results of polypropylene membrane hy drophilization were better if the alcohols with shorter alkyl chains w ere used, i.e. methyl, ethyl, and n-propyl alcohol. The use of a long- chain alcohol, e.g. n-butyl alcohol reduced the ''effectness'' of hydr ophilization because the penetration of such an alcohol into the polyp ropylene membrane pores was hampered.