Abstract: A mechanically undensified aromatic polyimide foam is made from an aromatic polyimide precursor solid residuum and has the following combination of properties: a density according to ASTM D-3574A of about 0.5 pounds/ft.sup.3 to about 20 pounds/ft.sup.3 ; a compression strength according to ASTM D-3574C of about 1.5 psi to about 1500 psi; and a limiting oxygen index according to ASTM D-2863 of about 35% oxygen to about 75% oxygen at atmospheric pressure. The aromatic polyimide foam has no appreciable solid inorganic contaminants which are residues of inorganic blowing agents. The aromatic polyimide which constitutes the aromatic polyimide foam has a glass transition temperature (Tg) by differential scanning calorimetry of about 235.degree. C. to about 400.degree. C.; and a thermal stability of 0 to about 1% weight loss at 204.degree. C. as determined by thermogravimetric analysis (TGA).

Abstract: A document feed component is presented comprising a foamed epichlorohydrin elastomer, a curing agent, and a blowing agent. The elastomer optionally further includes activators, polymerization accelerators, and a filler material. An important feature of the present invention is that the use of a foamed epichlorohydrin elastomer in accordance with the present invention does not require the use of processing aids and migratory additives. Consequently, the document feed component of this invention has the advantage of not contaminating paper or other media with which they come into contact, even for extended periods of time, while maintaining other advantageous properties, such as a high coefficient of friction, low hardness, low compression set, and excellent resistance to ultraviolet light and ozone. The document feed component of the present invention may be shaped as a roller, wheel, belt, pad or the like.

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 bonded 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: A method of preparing polyimide foam produces a foam with excellent flexibility properties. The method of preparing polyimide foam is performed by foaming polyimide percursor which is prepared by employing linear aliphatic diamine and aromatic diamine containing 4 to 12 carbon atoms, at specific weight ration into the esterified reaction mixture prepared by reacting an aromatic carboxylic acid or its anhydride with excess amount of an alcohol compound. The polyimide foam produced by the method described retins superior characteristics of conventional polyimide foams and in addition have excellent flexibility so that it is used widely as adiabatic material, acoustical absorbent and cushion material in the aerospace industry, submarine and express trains etc.

Abstract: A resorbable polymer suitable for producing a medical product, comprising a triblock terpolymer with a structure ABA formed from a biodegradable hard segment A and a biodegradable soft segment B, has as the soft segment a statistical terpolymer with a completely amorphous structure. A process for its production comprises chemically reacting the hard segment monomer with hydroxy terminal groups of the soft segment B. The resorbable medical product produced from the triblock terpolymer can be a textile fabric, produced from multifilaments, a film, membrane or an injection molding.

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: A urine absorber superior in smell extinguishing and urine absorption properties and in absorption stability is to be prepared. To this end, a polymer of styrene and/or conjugate diene and acrylonitrile, containing a predetermined amount of a sulfonide and/or its salts, is used as the urine absorber.

Abstract: A document feed component is presented comprising a foamed epichlorohydrin elastomer, a curing agent, and a blowing agent. The elastomer optionally further includes activators, polymerization accelerators, and a filler material. An important feature of the present invention is that the use of a foamed epichlorohydrin elastomer in accordance with the present invention does not require the use of processing aids and migratory additives. Consequently, the document feed component of this invention has the advantage of not contaminating paper or other media with which they come into contact, even for extended periods of time, while maintaining other advantageous properties, such as a high coefficient of friction, low hardness, low compression set, and excellent resistance to ultraviolet light and ozone. The document feed component of the present invention may be shaped as a roller, wheel, belt, pad or the like.

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: The present invention relates to highly asymmetric polymer membranes for ultrafiltration (UF), and to a simplified method of their manufacture. Disclosed herein are UF membranes with a high degree of asymmetry between the size of pores at the skin face of the membrane and the size of pores at the opposite face of the membrane. Asymmetry ratios of these membranes range from about 20 to about 1000. The porous support layer between the skin face and the opposite face is reticular and is substantially free of macrovoids. These membranes thus have higher flow rates than prior UF membranes. The membranes are cast from polymer dope mixes that are either homogeneous solutions or stable colloidal dispersions.

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: Highly asymmetric polyethersulfone membranes prepared from a stable, clear, homogeneous solution or stable colloidal dispersion of polyethersulfone are described. The membranes have a porous skin possessing a high density of skin pores with an average diameter of from about 0.001 micron to about 20 microns. In addition, the membrane has a porous support with an asymmetric region of gradually increasing pore diameters so that the opposite face of the membrane has an average pore diameter that is from about 50 to about 10,000 times the diameter of the skin pores.

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: A foamed polyarylene sulfide according to the invention has a density which is reduced by at least 50% compared with the theoretical density of nonfoamed material, and is expediently produced by subjecting a polyarylene sulfoxide as such or a mixture of one or more polyarylene sulfides with a polyarylene sulfoxide to heat treatment. The temperature of the heat treatment is in the range from 250.degree. to 400.degree. C.

Abstract: Molding compositions or mixtures comprising a high-temperature-resistant polymer and at least one polymer containing sulfoxide groups are used for the production of a foam by exposure to heat. The foam is employed for heat-resistant insulating layers.

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: A composition for a foam and a process for preparing it are provided, the composition including by weight (a) more than 25% of an active ingredient in powder form; (b) from 1 to 20% of a surfactant; the balance being composed of water, wherein the powder of the active ingredient has a particle size below 20 .mu.m. Foams, notably for rectal administration, containing this composition with a propellant gas are also provided.

Abstract: A foamed polyarylene sulfide according to the invention has a density which is reduced by at least 50% compared with the theoretical density of nonfoamed material, and is expediently produced by subjecting a polyarylene sulfoxide as such or a mixture of one or more polyarylene sulfides with a polyarylene sulfoxide to heat treatment. The temperature of the heat treatment is in the range from 250.degree. to 400.degree. C.

Abstract: Polyurethane foams having high resilience, significantly improved humid aging, excellent tear strength, and light color are formed from a polydiene diol, preferably a hydrogenated polybutadiene diol, having a hydroxyl functionality from 1.6 to 2.0 and from an aromatic polyisocyanate having an isocyanate functionality of from 1.8 to 2.5. The polydiene diol is preferably blended with foaming agents prior to addition of the highly reactive polyisocyanate.

Abstract: Molding compositions or mixtures comprising a high-temperature-resistant polymer and at least one polymer containing sulfoxide groups are used for the production of a foam by exposure to heat. The foam is employed for heat-resistant insulating layers.

Abstract: The present invention describes a method for preparing an asymmetric porous membrane by a dry-wet phase inversion method, which comprises contacting a cast or spun polymer solution with water or organic vapor prior to immersing into the non-solvent precipitation medium, whereby said water or organic vapor is adsorbed onto the cast or spun polymer solution. Higher permeability and excellent rejection ability can be obtained, due to the high porosity and uniform pore size of said membranes according to the present invention.

Abstract: A low density, high temperature resistant insulation material that is very thermally efficient, is easily moldable and is unaffected by water. The insulation material is especially suitable for use in aviation, aerospace and automotive applications. The insulation material contains inorganic fiber; inorganic binder; hydrophilic particulate inorganic material; hydrophobic particulate inorganic material; polymer; and preferably a setting agent and an opacifier.

Abstract: A method improves the adhesion of polyurethane foam to polycarbonate by providing reactive groups on the polycarbonate surface. The adhesion is further improved by utilizing a polyurethane mix with an isocyanate index greater than 82. Articles comprising polycarbonate and polyurethane foam adhered to the polycarbonate by the method of the instant invention, such as automobile dashboards, are also provided.

Abstract: A polymeric foam with continuous, open-cell pores containing living cells suitable for medical applications and methods for preparing these foams. The microporous foams are of controlled pore size that may be utilized in a variety of applications. In general, the foams are characterized in that the pores are continuous and open-celled. In preparing the foams, an organic polymer is melted and combined with a selected solid crystalline fugitive compound, that melts above about 25.degree. C. and/or that sublimates at above about 25.degree. C. or can be extracted, to produce a substantially isotropic solution. The solution is cooled under controlled conditions to produce a foam precursor containing the solidified fugitive composition dispersed through a matrix of the organic polymer. Crystals of fugitive composition are then removed by solvent extraction and/or sublimation, or a like process to produce microcellular foams having a continuous, open-cell structure.

Abstract: A foaming resin composition consisting essentially of (A) an organic compound having a carbon-carbon double bond, (B) a compound having an SiH group, and (C) a compound having an OH group is foamed and cured at room temperature or under heat at relatively low temperatures, to obtain hard, semi-hard or soft plastic foam having good weather resistance and good compatibility with coating compositions and adhesives.

Abstract: The present invention relates to biodegradable PHA copolymers comprising at least two randomly repeating monomer units. The present invention further relates to a plastic article comprising a biodegradable copolymer, wherein the biodegradable copolymer comprises at least two randomly repeating monomer units (RRMU) wherein the first RRMU has the structure ##STR1## wherein R.sup.1 is H, or C.sub.1 or C.sub.2 alkyl, and n is 1 or 2; the second RRMU has the structure ##STR2## wherein R.sup.2 is a C.sub.4 -C.sub.19 alkyl or alkenyl; and wherein at least 50% of the RRMUs have the structure of the first RRMU. The present invention further relates to an absorbent article comprising a liquid pervious topsheet, a liquid impervious backsheet comprising a film comprising a PHA of the present invention and an absorbent core positioned between the topsheet and the backsheet.

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 storage stable anaerobic composition which does not require constant aeration with a viscosity between 50,000 to 5,000,000 mPa.s and a volume expansion of between about 1 to 20% due to the creation within the composition by aeration of stable, uniform, microcellular foam.

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: Foams are prepared under reduced pressure and are subsequently encased in a material which will prevent ambient air from entering the cell voids. In the most preferred embodiment of the invention a polyurethane or polyisocyanurate foam is formed by mixing the polyol and isocyanate components under reduced pressure, allowing the gas within the foam to reach equilibrium at a lesser pressure then in prior systems. The need for blowing agents is substantially reduced and the K-factor of such foams is highly desirable. The foams are particularly well suited for use in refrigeration applications where the foams can be encased to prevent air from entering the cells after curing of the foam.

Abstract: The present invention relates to thermoplastic foams in which .beta.-ketocarboxylic acids, .beta.-ketocarboxylic acid esters or tert.-butyl esters of organic acids are used as the foaming agents.

Abstract: Resorbable materials and their preparation based on gelling a solution of a single polylactide enantiomer. The gel may be dried to produce solid materials, or may be extracted with a nonsolvent prior to drying to make microporous materials. Physical and mechanical properties of the material may be varied by varying the molecular weight of the gelling polymer, or by blending the gelling solution with other polymers or fillers. The resorbable materials can be used to make biodegradable implantation devices.

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: This invention relates to a foamed, cellular crosslinked vinyl lactam polymer and to a formed rigid product obtained therefrom having dimensional stability and a high Tg above 150.degree. C. The invention also relates to the method of preparing said molded cellular polymer.

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 thermoplastic molding composition suitable for the preparation of foam is disclosed. The composition comprises a thermoplastic resinous component and a foaming agent which includes A) (i) 0.01 to 4.8% alumina hydrate (aluminum hydroxide) in combination with (ii) 0.01 to 4.8% of an acidic additive or B) 0.01 to 4.8% of the reaction product of said (i) and said (ii), the percentages being relative to the weight of the composition to be foamed. The invention is based on the finding that the foaming of the composition does not lead to any significant reduction in molecular weight of the resinous component or to troublesome discoloration of the foam, even during its re-extrusion.

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: This invention relates to a foamed, cellular crosslinked vinyl lactam polymer and to a formed rigid product obtained therefrom having dimensional stability and a high Tg above 150.degree. C. The invention also relates to the method of preparing said molded cellular polymer.

Abstract: A soft, flexible foam characterized in having (i) a hardness, IFD 25% value, of at most 29 lbs/50 in.sup.2, as determined in accordance with Test B.sub.1 of ASTM D 3574 and (ii) a density of about 0.9 to 3.0. pounds per cubic foot is disclosed. Accordingly, the foam is prepared by reacting an organic polyisocyanate with a polyol in the presence of a catalyst and water and a compound conforming to ##STR1## where A is selected from among H, COOH, NH.sub.2, and OH, M is a counter ion, andwhere n, x and m are selected such that said compound has a number average molecular weight of about 500 to 20,000, a functionality of 0 to 10 and a sulfonate concentration of about 0.1 to 30 percent by weight.

Abstract: A foamed plastic is provided which is excellent in heat resistance and mechanical strength. The foamed plastic is produced by foaming a resin which comprises an N-alkyl-substituted maleimide unit in an amount of 30 to 98 mol % and an olefin unit in an amount of 70 to 2 mol % of the entire polymer, and has a weight-average molecular weight of from 1.times.10.sup.3 to 5.times.10.sup.6 in terms of polystrene.