Abstract: A process for producing a nanoporous polymer film of no greater than 10 micron thickness having low dielectric constant value, including the steps of: (a) providing a polymer in a solution with at least two solvents for the polymer in which a lowest boiling solvent and a highest boiling solvent have a difference in their respective boiling points of approximately 50° C. or greater; (b) forming a film of the polymer in solution with at least the two solvents on a substrate; (c) removing a predominant amount of the lowest boiling solvent; (d) contacting the film with a fluid which is a non-solvent for the polymer, but which is miscible with the at least two solvents to induce phase inversion in the film; (e) forming an average pore size in the film in the range of less than 30 nanometers. The present invention is also nanoporous films made by the above process.

Abstract: Regiospecific polyamide-imides are cast to form membranes which exhibit superior gas separation properties when compared to polyamide-imide membranes formed from random copolymers. The regiospecific polyamide-imides are synthesized by reacting specific aromatic diimide dicarboxylic acids with select aromatic diamines.

Abstract: The present invention is a class of semi-permeable polymeric membranes and processes for using such membranes to separate one or more components of a gas mixture. The membranes which are formed from a polymer blend of a first polyimide containing an aromatic diamine and a second polyimide containing an alkenylated diamine having an allyl or allylaryl group exhibit high gas perm-selectivities. The polyimide blends can be surface modified by treatment with an activating force such as high energy electromagnetic irradiation or with a free radical source to impart enhanced selectivity to the membrane without causing a large decrease in composite permeance. These membranes formed from polyimide blends are especially useful in effecting the separation of oxygen and nitrogen from air.

Abstract: Diamine compounds having the structural formula: ##STR1## wherein R.sub.1 is a methyl or ethyl group, can be used in preparing various polymers which are useful components in gas separation membranes. The combined effect of specific substituents ortho to the amino groups and the fluorenylidene bridging group imparts useful properties to polymeric membranes formed with these monomers.

Abstract: The present invention is a class of semi-permeable polyimide membranes and a process for using such membranes to separate one or more components of a gaseous mixture. The membranes are prepared from a polyimide having surface-modifiable functionalities comprising repeating units formed from an aromatic dianhydride and a bridged alkylated bisaniline wherein the bridging group of the diamine possesses restricted, rotatable rigid or low Van Der Waal energy substituents which are orthogonal to the polymer backbone. The membranes formed therefrom are contacted in the presence of an oxygen source with an activating force such as high energy electromagnetic irradiation to effect modification of the polymer surface. The surface-modified polyimide membranes exhibit high gas perm-selectivities and are especially useful in effecting the separation of oxygen and nitrogen from air.

Abstract: The present invention is a class of semi-permeable polyimide membranes and a process for using such membranes to separate one or more components of a gaseous mixture. The membranes are prepared from a polyimide having surface-modifiable functionalities comprising repeating units formed from an aromatic dianhydride and an alkyl-substituted phenylenediamine having at least one hydrogen atom located on a ring position ortho to an amine nitrogen. The membranes formed therefrom are contacted in the presence of an oxygen source with an activating force such as high energy electromagnetic irradiation to effect modification of the polymer surface. The surface-modified polyimide membranes exhibit high gas perm-selectivities and are especially useful in effecting the separation of oxygen and nitrogen from air.

Abstract: The present invention is a class of polymeric membranes formed from aromatic polyamides derived from dicarboxylic acid chlorides and cardo diamines having alkyl substituents on all portions ortho to the amine functions. These polyamide membranes exhibit high gas permselectivities and are useful in various gas separation applications.

Abstract: Diamine compounds having the structural formula: ##STR1## wherein R.sup.1 and R.sup.2 are independently methyl, ethyl or isopropyl groups, can be used in preparing various polymers which are useful in gas separation membranes. The combined effect of alkyl substituents ortho to the amino groups along with the specific bridging group imparts useful properties to polymeric membranes formed with these diamines.

Abstract: Water or gas containing organic impurities is purified by contact with a poly(trialkylsilylpropyne), such as poly[1-(trimethylsilyl)-1-propyne], operating as a bulk absorbent. Regeneration of the absorbent can be by vacuum or a stream of air.

Abstract: The present invention is a class of polyimide membranes wherein the diamine portion of the polymer structure is formed from 2,5-di-t-butyl-1,4-phenylenediamine. Membranes formed from polyimides containing this diamine structure exhibit unexpectedly high gas permeability properties and are especially useful for separating oxygen from nitrogen or air.

Abstract: The present invention is a class of polyimide membranes containing copolymerizable, surface modifiable units containing both aromatic diamines and alkenylated diamines having an allyl or allylaryl group preferably positoned ortho to an amine functionality. The polyimide membranes can be surface modified by treatment with an activating force such as high energy electromagnetic irradiation or with a free radical source to impart high selectivity to the membrane without causing a large decrease in composite permeance.

Abstract: The present invention is a class of polyimide membranes containing copolymerizable, surface modifiable units containing both aromatic diamines and alkenylated diamines having a vinyl or vinylaryl group preferably positioned ortho to an amine functionality. The polyimide membranes can be crosslinked by treatment with an activating force such as high energy electromagnetic irradiation or with a free radical source to impart high selectivity to the membrane without causing a large decrease in composite permeance.

Abstract: Polymeric trisubstituted silylalkynes useful for forming gas separation membranes are prepared at accelerated polymerization rates and with improved yields in the presence of a Group VV or VIB Metal halide catalyst such as TaCl.sub.5, by employing about 0.1 to 5 mole %, based upon total alkyne concentration, of a trialkylgermylalkyne compound.

Abstract: The present invention is a class of polyimide membranes wherein the diamine portion of the polymer structure is an alkylated bisaniline. The bridging group of the diamine possesses restricted, rotatable rigid, or low Van Der Waal energy substituents which are orthogonal to the polymer backbone. These polyamide membranes exhibit enhanced gas flux and are useful in various gas separation applications.

Abstract: The present invention is a modified polymeric membrane having improved selectivity for separating gas mixtures. The membrane comprises a silyl substituted polyacetylene polymer to which has been added 5 to 50 wt. % of an additive which is miscible with the polymer, has a boiling point >300.degree. C. at atmospheric pressure, is soluble in a common solvent for the polymer and increases the selectivity ratio of O.sub.2 /N.sub.2 by at least 15% over the polymer without the additive.

Abstract: Polymeric tri-substituted silylalkynes useful for forming gas separation membranes are prepared at accelerated polymerization rates and increased molecular weights by employing at polymerization temperatures a binary catalyst system of Group VB or VIB metal halide such as TaCl.sub.5 and a tertiary amine compound such as pyridine in an aromatic solvent.

Abstract: The present invention is a process for polymerizing trialkylsilylacetylene derived monomers to form the corresponding poly(trialkylsilylacetylene) polymer. The polymerization reaction is carried out in the presence of an organic solvent over a catalyst comprising a halide of a transition metal of group Vb or VIb. The molecular weight of the resultant polymer is decreased by adding to the reaction mixture, in a concentration between about 0.5-25 wt. %, a compound having the structural formula ##STR1## wherein each R is independently methyl, C.sub.2-4 alkyl or phenyl, and n is from 1 to 100.

Abstract: The present invention is a group of new polymers and treated, semi-permeable, polymeric membranes made from the new polymers, having improved selectivity for separating components of a gas mixture. The membrane is provided by fluorinating a polymer cast into membrane form, having the general structural formula: ##STR1## wherein R.sub.1 is H or a C.sub.1 -C.sub.2 alkyl group; R.sub.2 and R.sub.3 are independently linear or branched C.sub.1 -C.sub.6 alkyl groups; R.sub.4 is a linear or branched C.sub.1 -C.sub.12 alkyl or aryl group; X is a C.sub.1 -C.sub.3 alkyl group or phenyl; m is at least 100; and n is 0 or 1.

Abstract: The present invention is a treated, semi-permeable, polymeric membrane having improved selectivity for separating components of a gas mixture. The membrane is provided by fluorinating a polymer cast into membrane form, having the general structural formula: ##STR1## wherein R.sub.1 is a linear or branched C.sub.1 -C.sub.4 alkyl group; R.sub.2 and R.sub.3 are independently linear or branched C.sub.1 -C.sub.6 alkyl groups; R.sub.4 is a linear or branched C.sub.1 -C.sub.12 alkyl or aryl group; X is a C.sub.1 -C.sub.3 alkyl group or ##STR2## m is at least 100; and n is 0 or 1.

Abstract: This invention relates to a method for reducing the amount of wall fouling in the suspension polymerization of vinyl chloride. The surfaces of the polymerization reactor are wetted with a solution containing from 5 to 50 wt % alkali metal hydroxide, 0.01 to 1 wt % free radical inhibitor and 0.01 to 1 wt % surface active agent prior to charging the vinyl chloride polymerization recipe to the reactor. Preferably, the surface of the wetted reactor is heated to a temperature from 40.degree. to 100.degree. C. for at least 5 minutes prior to charging the polymerization recipe.