Abstract: Hydrophobic, asymmetric membranes are formed integrally from elastomeric polymers. The membranes have a dense, discriminating layer and a thick, porous support layer and require no other support. The membranes of the invention provide an economic advantage over prior art composite membranes used for separating target organics from a mixture. Using the methods of the invention it is possible to separate two or more organic components wherein discrimination is made on the basis of molecular size.

Abstract: Hydrophobic, asymmetric membranes are formed integrally from elastomeric polymers. The membranes have a dense, discriminating layer and a thick, porous support layer and require not other support. The membranes of the invention provide an economic advantage over prior art composite membranes used for separating target organics from a mixture.

Abstract: Using the methods of the invention, an elastomeric polymer is dissolved in a suitable solvent, cast in one of the membrane casting techniques using a phase inversion technique, and immersed in a coagulation bath comprised of suitable solvent/non-solvent pairs (e.g., THF/water and ethanol). Asymmetric membranes having a dense discriminating layer and a thicker porous support layer suitable for application in pervaporation processes were obtained in a single step. An increase of the polymer concentration in the casting solution gives a more dense layer. When cast as formed using the methods of the invention, the membrane obtained is an integrally skinned membrane comprising a thin, dense separation layer over a porous support layer (asymmetric membrane) formed in a single casting operation. The resulting membrane is homogenous with respect to chemical composition.

Abstract: Hydrophobic, asymmetric membranes are formed integrally from elastomeric polymers. The membranes have a dense, discriminating layer and a thick, porous support layer and require not other support. The membranes of the invention provide an economic advantage over prior art composite membranes used for separating target organics from a mixture.