| 摘要 |
The present invention is directed to a process for separating aromatic/non-aromatic mixtures a membrane comprised of a multi-block polymeric material comprising an ester prepolymer made by combining an (A) epoxy with a (B) dianhydride or its corresponding tetraacid or diacid-diester in an A/B mole ratio ranging from about 2.0 to 1.05, preferably about 2.0 to 1.1, chain extended with a second, different compatible prepolymer selected from the group of prepolymers comprising (a) and (A) diisocyanate combined with a monomer selected from (B) epoxy, polyester, dianhydride or it corresponding tetraacid or diacid-diester, and diamine in an A/B mole ratio ranging from about 2.0 to 1.05, preferably about 2.0 to 1.1, (b) and (A) dianhydride or its corresponding tetraacid or diacid-diester combined with a monomer selected from (B) diisocyanate, polyester, and diamine in an A/B mole ratio ranging from about 2.0 to 1.05, preferably about 2.0 to 1.1; and (c) and (A) diamine combined with a monomer selected from (B) epoxy, diisocyanate, and dianhydride or its corresponding tetraacid or diacid-diester in an A/B mole ratio ranging from about 2.0 to 1.05, preferably about 2.0 to 1.1, and mixtures thereof. The present invention is also directed to membranes made of the above recited multi-block polymeric materials, especially membranes comprising thin, dense (non porous) films of said multi-block polymeric material deposited on a micro-porous support layer producing a thin film composite membrane. The membranes of the multi-block polymeric material, especially the thin film composite membranes, are useful for separating aromatic hydrocarbons from mixtures of same with non-aromatic hydrocarbons under perstraction or pervaporation conditions.
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