MEMBRANAS DE POLIUREA/URETANO CON ELEVADO CONTENIDO DE COMPUESTOS AROMATICOS Y SU USO PARA SEPARAR COMPUESTOS AROMATICOS DE COMPUESTOS NO AROMATICOS

• Main Author: SCHUCKER, ROBERT CHARLES
• Format: Patent
• Language: Spanish
• Published: 01.10.1993
• Edition: 5
• Subjects: CHEMISTRY; COMPOSITIONS BASED THEREON; CRACKING HYDROCARBON OILS; FUELS; LUBRICANTS; MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONSONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS; METALLURGY; MINERAL WAXES; ORGANIC MACROMOLECULAR COMPOUNDS; PEAT; PERFORMING OPERATIONS; PETROLEUM, GAS OR COKE INDUSTRIES; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVEHYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, ORGASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; SEPARATION; TECHNICAL GASES CONTAINING CARBON MONOXIDE; THEIR PREPARATION OR CHEMICAL WORKING-UP; TRANSPORTING

MEMBRANAS NUEVAS, UTILES PARA LA SEPARACION DE AROMATICOS DE SUS MEZCLAS CON NO AROMATICOS EN, POR EJEMPLO, UNA CORRIENTE DE ALIMENTACION DE NAFTA, SE CARACTERIZA POR POSEER UN INDICE DE UREA DE APROXIMADAMENTE 20 % POR LO MENOS, PERO MENOS QUE 100 %, UN CONTENIDO EN CARBONO AROMATICO DE 15 % EN MOLES APROXIMADAMENTE POR LO MENOS, UNA CONCENTRACION DE GRUPOS FUNCIONALES POR LO MENOS 10 POR 100 G DE POLIMERO Y UNA RELACION C=O/NH MENOR QUE 8,0. ESTAS MEMBRANAS DE POLIUREA/URETANO MUY AROMATICAS SON MEMBRANAS DE PELICULA DENSA, SIMETRICAS, HECHAS DE LOS CORRESPONDIENTES POLIMEROS DE POLIUREA/URETANO POR TECNICAS DE FUNDICION DE MEMBRANAS PATRON. LOS COPOLIMEROS DE POLIUREA/URETANO PREFERIBLEMENTE SE PRODUCEN POR REACCION DE COMPUESTOS DIHIDROXI Y POLIHIDROXI, TALES COMO POLIETERES Y POLIESTERES QUE TIENEN PESOS MOLECULARES ENTRE 500 Y 5000 APROXIMADAMENTE, CON DIISOCIANATOS O POLIISOCIANATOS ALIFATICOS, ALQUILAROMATICOS O AROMATICOS Y EXTENSORES DE CADENA DE PESO MOLECULAR BAJO, TALES COMO DIAMINAS, POLIAMINAS O AMINOALCOHOLES. LAS MEMBRANAS SON UTILES PARA SEPARAR AROMATICOS DE NO AROMATICOS EN, POR EJEMPLO, REFINERIAS DE PETROLEO Y APLICACIONES QUIMICAS. Novel membranes, useful for the separation of aromatics from mixtures thereof with non-aromatics, in, for example, a naphtha feed stream, are characterized by possessing a urea index of at least about 20% but less than 100%, an aromatic carbon content of at least about 15 mole percent, a functional group density of at least about 10 per 1000 grams of polymer and a C = O/NH ratio of less than about 8.0. These highly aromatic polyurea/urethane membranes are symmetric, dense film membranes made from the corresponding polyurea/urethane copolymers by standard membrane casting techniques. The polyurea/urethane copolymers are preferably produced by reacting dihydroxy or polyhydroxy compounds, such as polyethers or polyesters having molecular weights in the range of about 500 to 5000 with aliphatic, alkylaromatic or aromatic diisocyanates or polyisocyanates and low molecular weight chain extenders, such as diamines, polyamines or amino alcohols. The membranes are useful for separating aromatics from non-aromatics in e.g., petroleum refining and chemical applications.