Abstract: Super-absorbing polymeric networks of crosslinked polyaspartates are produced from crosslinked polysuccinimide. Super-absorbing polymeric networks are produced in a single reaction vessel by crosslinking polysuccinimide with at least one organic polyamine crosslinking agent in the presence of at least one nitrogenous base. The reaction is carried out in an aqueous reaction mixture to produce a polymeric network of crosslinked polyaspartate.

Abstract: Superabsorbent fiber and film compositions comprising partially acidified, hydrolyzed, internally plasticized, crosslinked, superabsorbing fibers or film derived from polysuccinimide and processes for preparing same.

Abstract: Disclosed are methods of producing super-absorbing polymeric networks of polyaspartates from crosslinked polysuccinimide. In one preferred aspect, polysuccinimide is first reacted with an organic crosslinking agent, preferably an organic base containing at least two primary amine groups, to form a gelled crosslinked polysuccinimide. The gelled crosslinked polysuccinimide is then base hydrolyzed to a gelled polymeric network of polyaspartate and deswollen with at least one liquid alcohol to a polymeric network of polyaspartate which demonstrates super-absorbing capability in water and in electrolyte solution. Super-absorbing polymeric networks of polyaspartates can also be produced in a single reaction vessel by sequentially crosslinking a polysuccinimide with an organic crosslinking agent in an aqueous reaction medium, optionally containing a mineral acid, and then hydrolyzing the crosslinked polysuccinimide to produce a polymeric network of polyaspartate.

Abstract: A shaped article composed of an aromatic polyimide has a hollow, essentially spherical structure and a particle size of about 100 to about 1500 .mu.m, a density of about 1 to about 6 pounds/ft.sup.3 and a volume change of 1 to about 20% by a pressure treatment of 30 psi for 10 minutes at room temperature. A syntactic foam, made of a multiplicity of the shaped articles which are bounded together by a matrix resin to form an integral composite structure, has a density of about 3 to about 30 pounds/ft.sup.3 and a compression strength of about 100 to about 1400 pounds/in.sup.2.

Abstract: Composite materials made wholly from aromatic polyamides are prepared, which have the advantage of better performance and less delamination than composites composed of chemically distinct components. The foam matrix for such composites is prepared using N,N'-dialkylated aromatic polyamide. Both fiber reinforced foam structural forms and foam/felt laminates are prepared.

Abstract: A lightweight open celled foam, having a density no greater than 6 pounds per cubic foot (pcf) and a ratio of imide to amide groups greater than 1 to 1 and no greater than 19 to 1, is the reaction product made from an organic polyisocyanate having at least two functional groups per molecule and a mixture of a difunctional acid and a difunctional anhydride in the presence of a tertiary amine catalyst and a nonionic, organic surfactant having a hydrophilic/lipophilic balance (HLB) of at least 12, with the reactants generating carbon dioxide during the manufacturing process.

Abstract: A lightweight open celled foam, having a density no greater than 0.5 pounds per cubic foot (pcf), preferably between 0.1 and 0.4 pcf, and a ratio of imide to amide groups greater than 1 to 1 and no greater than 19 to 1, is the reaction product made from an organic polyisocyanate having at least two functional groups per molecule and a mixture of a difunctional acid and a difunctional anhydride in the presence of a tertiary amine catalyst and a surfactant, with the reactants generating carbon dioxide during the manufacturing process. The reaction is interrupted when the amount of carbon dioxide generated from the reactants is from about 1% to about 8% by weight of the total mass of the reactants. The reaction mass is transferred after the interruption step to a second stage to complete the generation of carbon dioxide and the formation of the low density foam product.

Abstract: Highly uniform microporous foam suitable for medical applications and methods for preparing these foams. The highly uniform microporous foams are of controlled pore size that may be utilized in a variety of applications. In preparing the foams, an organic crystalline polymer is melted and combined with a selected solid crystalline fugitive compound to produce a substantially isotropic solution. The solution is cooled under controlled conditions, which foster solid-solid phase separation by the simultaneous crystallization of the fugitive compound and the polymer, to produce a foam precursor containing the solidified fugitive compound dispersed through a matrix of the organic polymer. Crystals of fugitive compound are then removed by solvent extraction and/or sublimation, or like process to produce microcellular foams having a continuous, open-cell structure.

Abstract: A process for preparing superabsorbing crosslinked polyaspartate salt by reacting crosslinked polysuccinimide having a weight average molecular weight of at least 20,000 Daltons with neat base or aqueous base wherein the ratio of water to crosslinked polysuccinimide is zero or positive up to about 10, preferably about 3.3. The resulting salt is either a solid or paste.

Abstract: A method of preparing superabsorbent polymer as crosslinked polyaspartate salt by reacting polysuccinimide dissolved in organic solvent with crosslinker and reacting the polysuccinimide in situ with neat or a solution of alkali metal hydroxide to form the crosslinked salt.

Abstract: Highly uniform microporous foam suitable for medical applications and methods for preparing these foams. The highly uniform microporous foams are of controlled pore size that may be utilized in a variety of applications. In preparing the foams, an organic crystalline polymer is melted and combined with a selected solid crystalline fugitive compound to produce a substantially isotropic solution. The solution is cooled under controlled conditions, which foster solid--solid phase separation by the simultaneous crystallization of the fugitive compound and the polymer, to produce a foam precursor containing the solidified fugitive compound dispersed through a matrix of the organic polymer. Crystals of fugitive compound are then removed by solvent extraction and/or sublimation, or like process to produce microcellular foams having a continuous, open-cell structure.

Abstract: Disclosed are methods of producing super absorbing polymeric networks of polyaspartates from crosslinked polysuccinimide. In one preferred method aspect, polysuccinimide is first reacted with an organic crosslinking agent, preferably an organic base containing at least two primary amine groups to form crosslinked polysuccinimide. The crosslinked polysuccinimide is then hydrolyzed to a polymeric network of polyaspartate which demonstrates super absorbing capability in water and in saline solution. Alternative method aspects are disclosed in which super absorbing polymeric networks of polyaspartates are produced in a single reaction vessel by sequentially crosslinking polysuccinimide with organic crosslinking agent in an aqueous reaction mixture and then hydrolyzing the reaction product to produce a polymeric network of polyaspartate.

Abstract: A syntactic foam-core material and method for its production are disclosed wherein glass microspheres and chopped fiberglass are dispersed within a slurry comprised of a suitable resin such as an epoxy and a suitable solvent such as methyl ethyl ketone. Under carefully controlled vacuum and rate of addition conditions, the microspheres and chopped fiberglass are added to the slurry to form a light weight syntactic foam-core material. The material may either be stored under cold conditions for use at a later time as a B-stage material or it may be shaped and/or molded to conform to a desired configuration which, for example, may correspond with a desired component part. After curing, the material may be machined to final dimensions. The material may be characterized as a tightly packed network of resin-coated microspheres spaced by controlled, yet random voids comprising at least 20%, and more usually, between 23 and 25% by volume, of the fully-cured material.

Abstract: A polyamideamic acid resin prepolymer represented by formula A having isophorone diamine as one of monomers, ##STR1## in which k, l, m and n are integer of 1 or more, respectively, and ##EQU1## --R-- is at least one group selected from the group consisting of ##STR2## --R'-- is a cis- and trans-conformational mixture of ##STR3## high heat resistant polyamideimide foam produced therefrom, and processes for producing them are disclosed.

Abstract: The present invention relates to a process for forming a foamed elastomeric polymer. The process involves forming a reverse emulsion of liquid droplets in a continuous liquid phase of polymer precursor and then polymerizing the precursor to entrap uniformly distributed droplets of the liquid in pores formed in the polymer bulk. The liquid in the pores is then removed under supercritical conditions.

Abstract: A lightweight open celled foam, having a density no greater than 0.5 pounds per cubic foot (pcf), preferably between 0.1 and 0.4 pcf, and a ratio of imide to amide groups greater than 1 to 1 and no greater than 19 to 1, is the reaction product made from an organic polyisocyanate having at least two functional groups per molecule and a mixture of a difunctional acid and a difunctional anhydride in the presence of a tertiary amine catalyst and a surfactant, with the reactants generating carbon dioxide during the manufacturing process. The reaction is interrupted when the amount of carbon dioxide generated from the reactants is from about 1% to about 8% by weight of the total mass of the reactants. The reaction mass is transferred after the interruption step to a second stage to complete the generation of carbon dioxide and the formation of the low density foam product.

Abstract: The present invention relates to an insulating foamed polymer having a pore size less than about 1000 .ANG. made from a copolymer comprising a matrix polymer and a thermally decomposable polymer by heating the copolymer above the decomposition temperature of the decomposable polymer.

Abstract: A lightweight open celled foam, having a density no greater than 6 pounds per cubic foot (pcf) and a ratio of imide to amide groups greater than 1 to 1 and no greater than 19 to 1, is the reaction product made from an organic polyisocyanate having at least two functional groups per molecule and a mixture of a difunctional acid and a difunctional anhydride in the presence of a tertiary amine catalyst and a nonionic, organic surfactant having a hydrophilic/lipophilic balance (HLB) of at least 12, with the reactants generating carbon dioxide during the manufacturing process.

Abstract: A continuous process for making moldable foam beads comprising a non-crosslinked or crosslinked thermoplastic polymer foam are produced by mixing a composition comprising a non-crosslinkable or crosslinkable thermoplastic polymer or a thermoplastic polymer with a crosslinking agent, additives to achieve specific properties, a blowing agent, extruding the admixture under pressure, crosslinking, when applicable, the admixture under pressure, modulating the admixtures temperature to achieve the desired foaming properties, and then expanding the admixture in a zone of lower pressure to form a foam bead that can be molded.

Abstract: In a process for the preparation of poly-o-hydroxyamides and poly-o-mercaptoamides, a bis-o-aminophenol or a bis-o-aminothiophenol is reacted at a temperature of .ltoreq.0.degree. C. with a mixed dianhydride of a dicarboxylic acid and a sulfonic acid with the following structure:E--SO.sub.2 --O--CO--R*--CO--O--SO.sub.2 --Ewhere E is an (optionally substituted) methyl, phenyl, or naphthyl group and R* is the parent body of the dicarboxylic acid.

Abstract: Radially layered copoly-dendrimers having unusual surface properties and novel applications have been synthesized and characterized. These are the first copolymeric dendrimers composed of a hydrophilic poly(amidoamine) (PAMAM) interior with hydrophobic organosilicon surfaces. These dendrimers have been prepared by surface modifications of an ethylene diamine core PAMAM dendrimer with (3-acryloxypropyl)methyldimethoxysilane, (3-acryloxypropyl)bis(vinyldimethylsiloxy)methylsilane, (3-acryloxypropyl)tris(trimethylsiloxy)silane, chloromethyltrimethylsilane, and chloromethyldimethylvinylsilane, to varying degrees of surface coverage. The obtained products were characterized by .sup.1 H, .sup.13 C, and .sup.29 Si NMR, and by DSC and TGA. The dendrimers with less completely covered organosilicon surfaces are water soluble, and have considerable surface activity, the best of which lowered the surface tension of water to less than 30 mN/m.

Abstract: A vibration-absorbing element comprised of a foamed thermoplastic polymer selected from the group consisting of polyamide elastomers, EPDM polymers and SEBS polymers containing conventional additives, the foam structure having a pore size which decreases from the inside towards the outer surface and terminating in a smooth closed surface.

Abstract: In a process for the preparation of poly-o-hydroxyamides and poly-o-mercaptoamides, a bis-o-aminophenol or a bis-o-aminothiophenol is reacted with a dicarboxylic acid derivative of the following structure: ##STR1## with D=O, S, or NH and where R* is the parent body of the dicarboxylic acid and the groups R.sup.1 through R.sup.4 are H, F, CH.sub.3, or CF.sub.3 (with a maximum of two CH.sub.3 or CF.sub.3 groups).

Abstract: A syntactic foam-core material and method for its production are disclosed wherein glass microspheres and chopped fiberglass are dispersed within a slurry comprised of a suitable resin such as an epoxy and a suitable solvent such as methyl ethyl ketone. Under carefully controlled vacuum and rate of addition conditions, the microspheres and chopped fiberglass are added to the slurry to form a light weight syntactic foam-core material. The material may either be stored under cold conditions for use at a later time or it may be shaped and/or molded to conform to a desired configuration which, for example, may correspond with a desired component part. After curing, the material may be machined to final dimensions.

Abstract: Disclosed are methods of producing super absorbing polymeric networks of polyaspartates from crosslinked polysuccinimide. In one preferred method aspect, polysuccinimide is first reacted with an organic crosslinking agent, preferably an organic base containing at least two primary amine groups to form crosslinked polysuccinimide. The crosslinked polysuccinimide is then hydrolyzed to a polymeric network of polyaspartate which demonstrates super absorbing capability in water and in saline solution. Alternative method aspects are disclosed in which super absorbing polymeric networks of polyaspartates are produced in a single reaction vessel by sequentially crosslinking polysuccinimide with organic crosslinking agent in an aqueous reaction mixture and then hydrolyzing the reaction product to produce a polymeric network of polyaspartate.

Abstract: A continuous process for making moldable foam beads comprising a non-crosslinked or crosslinked thermoplastic polymer foam are produced by mixing a composition comprising a non-crosslinkable or crosslinkable thermoplastic polymer or a thermoplastic polymer with a crosslinking agent, additives to achieve specific properties, a blowing agent, extruding the admixture under pressure, crosslinking, when applicable, the admixture under pressure, modulating the admixtures temperature to achieve the desired foaming properties, and then expanding the admixture in a zone of lower pressure to form a foam bead that can be molded.

Abstract: A method and apparatus for producing a lightly crosslinked polyolefin foam and articles made therefrom is disclosed. According to the method, a polyolefin resin is lightly crosslinked, mixed with a blowing agent, forwarded as a molten gel admixture through an extruder, cooled, and expelled from a die into a zone of lower pressure, e.g., the atmosphere or a controlled pressure zone, to produce a uniform fine celled expanded shape.

Abstract: A process for preparing a novel superabsorbent polymer which is readily hydrolyzed and conform to environment by reacting a polysuccinimide with a diamine in an aqueous solution or an organic solvent to partially crosslink the polysuccinimide, and subsequently or concurrently hydrolyzing the remaining imide ring with an alkali while controlling the pH; and the superabsorbent polymer thus obtained.

Abstract: This invention relates to an article comprising a potted electrical component in a structure, wherein the electrical component is potted in a polyimide composition. The invention also relates to a method of potting electrical components comprising the steps of (1) adding a polyimide precursor to a structure including an electrical component, (2) curing the polyimide precursor to form a polyimide composition encapsulating the electrical component.

Abstract: Polymeric foams with novel chemical compositions are prepared by the condensation of specially-synthesized precursors, which contain (in addition to carbon and hydrogen) one or more of the following elements: oxygen, fluorine, nitrogen (in structures with stable chemical bonds), silicon, boron, phosphorus (in high oxidation states), and certain metals (and/or their oxides and hydroxides). Upon mixing in the proper proportions and/or heating these precursors react rapidly to generate polymeric networks, consisting of heterocyclic crosslink centers, connected with heterochain segments; hydrogen is largely eliminated or replaced by fluorine. These structures possess inherent nonflammability and high thermoxidative stability. Foaming is effected by the gaseous by-products of the condensation reactions, as well as by the addition of foaming agents. The resulting foam products can be formulated to have a wide range of densities and flexibilities.

Abstract: A film forming solution which does not require aprotic polar solvents, a porous film of poly(4,4'-oxydiphenylenepyromellitimide) obtained from the film forming solution which has excellent heat and chemical resistances, which is controllable in terms of porosity and pore size of the film and which has excellent electrical characteristics, and a coated material where the porous film is formed on a base material.Particularly, a film forming solution of a precursor of poly(4,4'-oxydiphenylenepyromellitimide) and a mixture of at least three solvents which are poor solvents for the precursor when each solvent is used alone, a porous film of poly(4,4'-oxydiphenylenepyromellitimide) obtained from the film forming solution and a coated material where the porous film is formed on a base material.

Abstract: The pourable porous carrier material is produced from at least one thermoplastic basic polymer with additives incorporated in the porous structure.First suitable foaming agents are added to the basic polymer, the mass is melted, mixed before and/or after melting. The mixture is then preferably extruded and cooled to form a pourable porous carrier material.At least one additive is added to the porous carrier material and mixed with this at a temperature (T.sub.M) below the melting point of the basic polymer but above the melting point of the additive.The porous carrier material has preferably ellipsoid pores which are brought into their longitudinal form during extrusion.

Abstract: An acrylic/lactam monomer based polymeric resin is provided which has excellent weatherability, outstanding transparency and optical clarity, improved heath and solvent resistance, as well as improved impact strength. The acrylic/lactam monomer based polymeric resin is formulated by the catalytic activation at ambient temperature of a polymerization syrup which contains from about 300 to about 2970 parts by volume of an acrylic monomer, from about 30 to about 2700 parts by volume of a lactam monomer, from about 0.3 parts to about 40 parts by volume of a mercaptan chain transfer agent and from about 0.3 to about 40 parts by volume of a crosslinking agent capable of crosslinking the acrylic monomer and the lactam monomer. To prevent further polymerization of the polymeric constituents of the polymerization syrup, as well as to enhance the shelf life of the polymerization syrup, an effective amount of a polymerization inhibitor and an ultraviolet light stabilizer are incorporated into the polymerization syrup.

Abstract: A process for preparing a novel superabsorbent polymer which is readily hydrolyzed and conform to environment by reacting a polysuccinimide with a diamine in an aqueous solution or an organic solvent to partially crosslink the polysuccinimide, and subsequently or concurrently hydrolyzing the remaining imide ring with an alkali while controlling the pH; and the superabsorbent polymer thus obtained.

Abstract: A process for producing thin microporous polymeric films for a variety of uses. The process utilizes a dense gas (liquified gas or supercritical fluid) selected to combine with a solvent-containing polymeric film so that the solvent is dissolved in the dense gas, the polymer is substantially insoluble in the dense gas, and two phases are formed. A microporous film is obtained by removal of a dense gas-solvent phase.

Abstract: An acrylic/lactam monomer based polymeric resin is provided which has excellent weatherability, outstanding transparency and optical clarity, improved heath and solvent resistance, as well as improved impact strength. The acrylic/lactam monomer based polymeric resin is formulated by the catalytic activation at ambient temperature of a polymerization syrup which contains from about 300 to about 2970 parts by volume of an acrylic monomer, from about 30 to about 2700 parts by volume of a lactam monomer, from about 0.3 parts to about 40 parts by volume of a mercaptan chain transfer agent and from about 0.3 to about 40 parts by volume of a crosslinking agent capable of crosslinking the acrylic monomer and the lactam monomer. To prevent further polymerization of the polymeric constituents of the polymerization syrup, as well as to enhance the shelf life of the polymerization syrup, an effective amount of a polymerization inhibitor and an ultraviolet light stabilizer are incorporated into the polymerization syrup.

Abstract: A small cell foam having a modified dense star polymer or dendrimer is described. This modified dense star polymer or dendrimer has a highly branched interior of one monomeric composition and an exterior structure of a different monomeric composition capable of providing a hydrophobic outer shell and a particle diameter of from about 5 to about 1,000 nm with a matrix polymer.

Abstract: Dense star polymers or dendrimers, modified by capping with a hydrophobic group capable of providing a hydrophobic outer shell, act as molecular nucleating agents in forming a polymer blend.

Abstract: Dense star polymers or dendrimers, modified by capping with a hydrophobic group capable of providing a hydrophobic outer shell, act as molecular nucleating agents. These modified dense star polymers or dendrimers are particularly effective for the production of small cell foams.

Abstract: Porous, distensible, gel-like membranes which in tubular form are suitable as implants, e.g., vascular prostheses and a process for the preparation thereof is described. The membranes are formed by a spraying, phase-inversion technique which employs thermodynamically unstable polymer solutions and is accomplished by separately spraying the unstable solution and a nonsolvent onto a rotating surface. Prostheses from the highly porous tubular membranes have shown a high degree of patency and completeness of the healing process and are useful for direct implantation in the body or for extracorporeal vascular accesses.

Abstract: A method of and apparatus for continuously foaming a polyimide prepolymer powder which is not susceptible to heating by microwave energy utilize a preheated conveyor belt to heat the powder in contact with and adjacent the surface of the conveyor belt to commence the reaction and foaming of the powder as it enters an oven which further heats the powder by convection and infrared radiation to form a continuous foam bun. The conveyor belt is cooled as it exits the oven to cool a bottom surface of the foam product to enable the foam product to be removed from the conveyor before interior portions of the foam product have cooled. Foam adhering to the conveyor belt, after the product has been removed, is cleaned from the conveyor belt, collected and mixed with and used as a filler in the prepolymer powder used in the process. In addition the mass of the powder entering the oven and the density and degree of cure of the foam bun exiting the oven are monitored to continuously control the process.

Abstract: A polyamide precursor of a polybenzazole polymer is prepared by reacting an aromatic bis(alkenyl)ester with a ring forming, aromatic diamine. The precursor can be prepared in an organic solvent for the monomers to form a soluble polyamide precursor which can be subsequently cyclocondensed to form a PBX polymer. A polybenzoxazole precursor is prepared by the reaction of a bis(alkenyl)ester and a bis(ortho-hydroxyamine). A polybenzazole polymer is easily prepared by heating the polyamide, PBX precursor.

Abstract: A polyamide fiber comprised of (A) a thermoplastic aliphatic polyamide having copolymerized therein a polyalkylene oxide unit and having a melting point of at least 160.degree. C., and (B) a polyoxyalkylene glycol, wherein the ingredient (B) is finely dispersed in the ingredient (A). A polyamide fiber exhibiting a rate of moisture absorption of at least 3.5%/5 minutes at 25.degree. C. and R.H. 90% and/or a triboelectric voltage of not larger than 1.5 kV at 20.degree. C. and R.H. 40% is obtained by removing the ingredient (B) from the above-mentioned polyamide fiber by means of dissolution.

Abstract: A polyimide foam is prepared by heating a mixture comprising an alkyl ester of 4,4'-oxydiphthalic acid and a diamine at a temperature of 60.degree. to 350.degree. C. This foam is elastic and flame-retardant and has an excellent resistance to acid and alkali.

Abstract: Polyimide foam of desired density is produced by adding to a polyimide precursor comprising carboxylic and diamine components at least one foam-enhancing polar, protic additive of the formula ROH, where R is hydrogen, or C.sub.1 to C.sub.12 linear or branched alkyl or cycloalkyl, unsubstituted or substituted with halo, aryl, alkoxy or hydroxy, and heating the resultant slurry to a temperature that does not exceed about 105.degree. C. to form a homogeneous melt. When heated to a higher temperature the melt foams and cures. The density of the foam is affected by the amount of foam-enhancing additive which is utilized.

Abstract: The invention is directed to an unfoamed foil of at least one thermoplastic resin, said foil being capable of serving as an adhesive when softened and having included therein at least one blowing agent, and to the use thereof in preparing laminates.

Abstract: Fine, porous polybenzimidazole-containing particles prepared by spray-atomizing/quenching a polybenzimidazole-containing polymer solution into porous polybenzimidazole-containing particles, and fluidized bed, oppose jet milling the particles into fine, porous polybenzimidazole-containing particles. The milled particles exhibit a narrow particle size distribution centered at about a 5 .mu.m mean particle size, a surface area of about 35 m.sup.2 /g, and an open porosity of about 1.2 cm.sup.2 /gm which is at pore radius of less than about 100 nm.

Abstract: A method of forming complex polyimide foam shapes by impregnating a low density, open cell, reticulated foam with polyimide foam precursor, placing the combination in a mold, closing the mold, then heating the assembly to the foaming and curing temperatures of the precursor. As the powdered precursor expands, it spreads throughout the reticulated foam producing a product having substantially uniform density and polyimide foam characteristics. If desired, the reticulated foam can be removed from the product by using a material that outgasses and boils away at polyimide processing temperatures. Radar absorbing materials may be incorporated in the reticulated foam so that the final product will have uniformly distributed radar absorbing components with the desirable high temperature resistance and other properties of polyimide foams.

Abstract: The invention relates to a polyamide substrate with a high concentration of amine groups, and a method of transferring biological materials by adsorption onto said substrate.

Abstract: A process for forming polymer powders by dissolving one or more polymers in a suitable solvent, followed by atomizing the solution into a droplet atmosphere of a non-solvent to precipitate polymer particles. The particles are separated from the non-solvent, washed and dried to produce a powder with a rounded particle morphology, high internal porosity and surface area, and high apparent density.Polymer powders with these properties can be pressed to dense shaped articles suitable for sintering in automated presses because the powders have good low and compressibility characteristics. The process if particularly useful when applied to soluble polymners that are not readily shaped by melt processing means.