The invention discloses an alkali-resistant
ultrafiltration membrane and a preparation method thereof. The alkali-resistant
ultrafiltration membrane is prepared from, by weight, 5-30 parts of
polyvinyl chloride, 1-20 parts of
polyvinylidene fluoride, 0-20 parts of an additive and 30-95 parts of a
solvent. The preparation method of the alkali-resistant
ultrafiltration membrane comprises the following steps of: pre-treating membrane preparation raw materials; mixing the prepared raw materials with an
organic solvent to obtain a membrane
casting solution; putting the membrane
casting solution into a defoaming tank for defoaming, feeding the fully defoamed
mixed solution into a
spinning machine, extruding by using a
spinning nozzle to form hollow fibrils, and after part of
solvent in the fibrils is evaporated, soaking the fibrils into a 2%
glycerol solution coagulating bath for soaking and forming. The alkali-resistant ultrafiltration membrane provided by the invention has excellent
chemical stability, acid and alkali resistance,
electrolysis resistance, good strength and flexibility and very strong anti-
pollution capability, the service life of the alkali-resistant ultrafiltration membrane is prolonged by the preparation method provided by the invention, and the hydrophilicity of the alkali-resistant ultrafiltration membrane is effectively prevented from losing effect due to
drying when being placed in air.