摘要 |
A polymeric porous membrane having a matrix made from an aliphatic thermoplastic polyamide or from an aliphatic thermoplastic polyamide/polyimide copolymer which has both relatively non-crystalline and relatively crystalline portions is provided. A method for preparing such a membrane comprises dissolution of an aliphatic thermoplastic polyamide or polyamide/polyimide copolymer having crystalline and noncrystalline portions such that the non-crystalline portions dissolve. At least some of the crystalline portions form a colloidal dispersion which is formed into a film. Dissolved non-crystalline portions are subsequently precipitated to form the porous membrane matrix. The pores in the membrane are defined by spaces between the relatively crystalline portions and at least some of the relatively crystalline portions are linked together by the reaction of a bis-aldehyde with the membrane matrix. |