| 摘要 |
A new porous membrane is composed of a phenylene -sulphide copolymer represented by general formula (-Ph-S-) m(Ph-X-)n (I), where pH is a phenylene group; X is -SO2 or -CO-; m , n = a natural number, m + n = 80-400. The porous membrane has a nonuniform structure in which one or more dense layers, formed on one or both sides of the membrane, provide the separation function. The porous layer has a larger void volume than the dense layer and is formed in contact with the dense layer. The phenylene sulphide copolymer can be represented by general formula -(-Ph-S-Ph-X-)q- (II) where q = an integer between 80 and 400. X is preferably -SO2-. Ph is preferably p-phenylene group. The dense layers has a separation ability which can reject 10 wt. % polyethylene glycol from polyethylene glycols having a molecular weight of 100,000. The thickness of the porous membrane is 10-100 microns. The void volume of the whole membrane is 20-80 %. The permeability of the membrane to pure water, under a pressure of 1kg/cm2 at 25 C, is 0.1 m3/m2. The porous membrane is laminated on a woven or nonwoven fabric made of polyester, polyamide, polyethylene, polypropylene or polyphenylene sulphide. |
