Abstract: This invention relates to vinyl ether-based coatings for which properties such as color stability, thermal stability, mechanical stability, hydrolytic stability, and resistance to embrittlement may be maintained and properties hydrogen generation and blocking are minimized.

Abstract: This invention relates to vinyl ether-based coatings for which properties such as color stability, thermal stability, mechanical stability, hydrolyric stability, and resistance to embrittlement may be maintained and properties hydrogen generation and blocking are minimized. The invention also relates to stabilizers which control these properties in the coatings.

Abstract: This invention relates to vinyl ether-based coatings for which properties such as color stability, thermal stability, mechanical stability, hydrolytic stability, and resistance to embrittlement may be maintained and properties hydrogen generation and blocking are minimized.

Abstract: A thermosetting resin designated a "APT" resin is produced by a two-step procedure in which a substituted aromatic compound, preferably diphenyl ether is reacted with formaldehyde to produce an oligomeric backbone, followed by further reaction with a phenol to provide pendant phenolic groups. Finally, the resulting polymer is cyanated with a cyanogen halide.

Abstract: This invention concerns novel o,o'-bismaleimide resins which have good processibility, novel o,o'-diamines used to prepare the resins, and the novel o,o'-bismaleimide polymers prepared by curing these resins. The polymers have thermo-oxidative and tensile properties which rival conventional p,p'- and m,m'-bismaleimide resin systems.The o,o'-bismaleimide resins of this invention have the following structure: ##STR1## wherein Y--G--Y is a bridging group with Y selected from the group consisting of oxygen, sulfur, and selenium, and G selected from a number of structures having aromatic and/or siloxane character. R.sub.a and R.sub.b are independently selected from the group consisting of hydrogen, an alkyl containing up to 4 carbon atoms, the corresponding alkoxy groups, chlorine, and bromine, or R.sub.a and R.sub.b together form a fused 6-membered aromatic ring.

Abstract: A class of di-ortho-substituted bismaleimides undergo uncatalyzed Michael addition with polyhydric phenols to afford chain-extended bismaleimides having a significantly wider processing window than the non-extended parent. The fully cured resins show improved fracture toughness, generally have comparable or superior dielectric constant and dielectric loss, and show no degradation in other properties such as resistance to moisture, to methylene chloride, and coefficient of thermal expansion.

Abstract: APO-BMI is a chain-extended with certain diamines to provide thermosetting resins retaining the improved properties of APO-BMI resins, but having increased toughness in the cured resins.

Abstract: Semipermeable membranes which may be used in a variety of separation processes such as desalination, sugar separation, etc. are prepared by contacting a porous support backing material such as polysulfone with an aqueous solution of a hydrazine compound. The coated support material is then contacted with an organic solution of an aromatic polycarboxylic acid chloride whereby an interfacial polymerized condensation reaction product is formed on the surface of the support. The thus formed composite is then cured at an elevated temperature and recovered.

Abstract: Chlorine-resistant semipermeable membranes which comprise an interfacial polymerized reaction product composited on a porous support backing material may be prepared by contacting a porous support material such as polysulfone with an aqueous solution of an aromatic polyamine containing a chlorine substituent on the aromatic ring such as 5-chlor-m-phenylenediamine. The coated support material is then contacted with an organic solvent solution of aromatic polycarboxylic acid chloride such as trimesoyl chloride for a period of time sufficient to form an interfacial polymerized reaction product on the surface of the support material. The resultant semipermeable membrane is then cured at curing conditions to form the desired composite. The resultant membrane composite may be used in separation processes such as desalination of brackish or sea water, the membrane being resistant to attack by chlorine which is present in the water.

Abstract: Anion exchange resins which have been exchanged with molybdate at acid pH are effective catalysts for epimerizing compounds with the structural unit: ##STR1## Cheif among these are aldoses, especially aldopentoses and aldohexoses, as well as some deoxy-sugars. A method for the continuous epimerization of aldoses and other compounds having the necessary structural feature shown using a fixed bed of molybdate-exchanged resin is quite efficient, and can be employed in enhancing the yield of the thermodynamically formed epimer which is produced as the minor epimer in a mixture under kinetic control.

Abstract: Saline water containing a chlorine-containing compound in the form of free chlorine, hypochlorite, etc. which has been added as a disinfectant or antibacterial compound is desalinated by passing the saline water through a semipermeable membrane which is resistant to the chlorine. The saline water is passed through this membrane at a temperature in the range of from ambient to about 50.degree. C. and a pressure in the range of from about 1380 to about 6895 kPA (200-1000 psi). The chlorine-resistant semipermeable membrane comprises an interfacial polymerized condensation reaction product composited on a porous backing support material which has been prepared by contacting a porous support material such as polysulfone with a solution of a diaryl methylene monomer containing at least one amine radical on each aryl nucleus.

Abstract: Chlorine-resistant semipermeable membranes which comprise an interfacial polymerized reaction product composited on a porous support backing material may be prepared by contacting a porous support material such as polysulfone with an aqueous solution of an aromatic polyamine containing a chlorine substituent on the aromatic ring. The coated support material is then contacted with an organic solvent solution of aromatic polycarboxylic acid chloride for a period of time sufficient to form an interfacial polymerized reaction product on the surface of the support material. The resultant membrane composite may be used in separation processes such as desalination of brackish or sea water, the membrane being resistant to attack by chlorine which is present in the water.

Abstract: Thermally stable polymers may be cross-linked by appending biphenylene moieties to the polymer backbone, then heating the modified polymer at a temperature in excess of about 300.degree. C. The cross-link density of the cured polymer can be controlled by varying the relative population of biphenylene moieties on the polymer backbone. Properties of the modified but uncured polymer are essentially the same as those in the original thermally stable polymer.

Abstract: Thin film composite membranes having as a permselective layer a film of a homopolymer of certain vinyl alkyl ethers are useful in the separation of various gases. Such homopolymers have a molecular weight of greater than 30,000 and the alkyl group of the vinyl alkyl monomer has from 4 to 20 carbon atoms with branching within the alkyl moiety at least at the carbon atom bonded to the ether oxygen or at the next adjacent carbon atom. These membranes show excellent hydrolytic stability, especially in the presence of acidic or basic gaseous components.

Abstract: Semipermeable composite membranes which comprise an interpenetrating polymer network of the isocyanate-capped polymer which is the reaction product of a polyether and an isocyanate with a copolymer containing at least two saturated or unsaturated heterocyclic nitrogen-containing compounds composited on a porous backing support material may be used in various separation systems. These separation systems may include reverse osmosis, ultrafiltration, gas separation, dialysis, etc., an especially useful system being the separation of sugars.

Abstract: Water-insoluble proton-conducting polymers which may be formed into membranes which are used in gas separation or gas sensing processes comprise an interpenetrating polymer network. This IPN is formed from the interaction between a host polymer and a guest polymer which is subsequently cross-linked or cured. The host polymer blend is formed from a phosphoric acid or sulfuric acid and a polymer or copolymer of a compound which possesses repeat units such as, for example, hydroxy ethylene, vinyl sulfonic acid, ethylene imine, etc, while the guest polymer is formed from a monofunctional monomer such as methacrylic acid and a difunctional cross-linking agent such as methylenebisacrylamide.

Abstract: Semipermeable composite membranes which comprise an interpenetrating polymer network may be prepared by reacting polyethylene glycol with a toluene diisocyanate to form an isocyanate-capped polyether, thereafter admixing the isocyanate-capped polyether with a heterocyclic nitrogen-containing compound to form an interpenetrating polymer network membrane-forming composition, forming a film of the composition on a porous support backing material and curing the resultant composite in a hydrous atmosphere to generate an amine-capped polymer, and subsequently reacting a portion of the isocyanate groups present to form a substituted polyurea which will physically enter the heterocyclic nitrogen-containing compound in the membrane.

Abstract: Apparatus and method for performing an electrochemical process involving hydrogen and gaseous compounds capable of dissociating into or combining with hydrogen ions using a solid electrolyte concentration cell. Specific applications are fuel cells for producing an electrical current and separation of hydrogen from a gaseous mixture. A novel proton-conducting membrane comprised of an interpenetrating polymer network serves as the solid electrolyte. For increased strength, a membrane may be composited with or utilized with a porous support.

Abstract: Apparatus and method for detecting and measuring hydrogen and gaseous compounds capable of dissociating into or combining with hydrogen ions using a solid electrolyte concentration cell. A novel proton-conducting membrane comprised of an interpenetrating polymer network serves as the solid electrolyte. A reference gas or a solid reference substance is used. For increased strength, a membrane may be composited with or utilized with a porous support.

Abstract: Chlorine-resistant semipermeable membranes which comprise an interfacial polymerization reaction product composited on a porous backing support material may be prepared by contacting a porous support material such as polysulfone with an aqueous solution of triaryl triamine. The coated support material is then contacted with an organic solvent solution of an aromatic polycarboxylic acid chloride for a period of time sufficient to form an interfacial polymerized reaction product on the surface of the support material. The resultant membrane composite may be used in separation processes such as desalination of brackish or sea water, the membrane resistant to attack by chlorine which is present in the water.