Abstract: Disclosed is a process for the continuous preparation of high internal phase emulsions which are suitable for subsequent polymerization into polymeric foam materials that, upon dewatering, act as absorbents for aqueous body fluids. The process involves continuous introduction of a certain type of monomer-containing oil phase and a certain type of electrolyte-containing water phase into a dynamic mixing zone at relatively low water to oil phase ratios. Flow rates are then steadily adjusted to increase the water to oil ratio of the streams fed to the dynamic mixing zone while subjecting the dynamic mixing zone contents to shear agitation which is sufficient to thereby form a high internal phase emulsion that, upon subsequent polymerization, provides a foam having an average cell size of from about 5 to 100 microns. The formation of such a stable high internal phase emulsion is completed by feeding the contents of the dynamic mixing zone to and through a static mixing zone.

Abstract: A microporous particulate-filled thermoplastic polymeric article is provided. The article can be in the form of a film, a fiber, or a tube. The article has a thermoplastic polymeric structure having a plurality of interconnected passageways to provide a network of communicating pores. The microporous structure contains discrete submicron or low micron-sized particulate filler, the particulate filler being substantially non-agglomerated.

Abstract: A method of preparing synthetic enzymes and synthetic antibodies in which method use is made of the so called molecular imprinting method, is described. As imprinting molecules use is made of transition state analogues, substrate-like compounds and antigen-like molecules, respectively. There is also described the use of the so prepared enzymes and antibodies.

Abstract: A porous polysulfone membrane and process for the preparation of porous polysulfone media suitable for use in filtration comprises blending polysulfone with a particulate solid or with said particulate solid and a second polymer, extruding the resultant blend to form an article and leaching the particulate solid and second polymer from the article.

Abstract: A process for producing an article of a synthetic resin material or a thermoplastic resin blend having a microcellular structure comprises dispersing in a solid thermoplastic resin matrix having hydrophilic functional groups a finely divided water-soluble material, shaping the resin matrix containing the water-soluble material into the desired article, and immersing the shaped article in water at a suitable temperature to cause the resin matrix to swell to an extent of at least about 50% by volume while wet. The immersion causes water to diffuse into the resin matrix and solvate the water-soluble material, which becomes encased in water-filled cells that have solid walls, are substantially closed, and do not form an interconnecting porous network.Articles made by this process include, among others, vascular grafts and organoids.

Abstract: Organic aerogels that are transparent and essentially colorless are prepa from the aqueous, sol-gel polymerization of melamine with formaldehyde. The melamine-formaldehyde (MF) aerogels have low densities, high surface areas, continuous porsity, ultrafine cell/pore sizes, and optical clarity.

Abstract: The invention relates to a process for preparing a microporous membrane, starting from a mixture of at least a hydrophobic polymer and a hydrophilic polymer, by dissolving these polymers first in a suitable solvent or mixture of solvents and subsequently by coagulating in a coagulation bath. According to the invention a more or less hydrophilic membrane is prepared by removing the membrane so obtained from the coagulation bath and subsequently by leaching at least a part of the hydrophilic polymer from the matrix, alternatively followed by hydrophobization. Said leaching of the hydrophilic polymer occurs by treatment of the membrane with an oxidizing/hydrolizing agent. The invention furthermore comprises microporous membranes, flat or tubular or in the form of hollow fibers, having a good chemical resistance and good mechanical strength.

Abstract: An active agent delivery device comprises (a) microporous material comprising a matrix consisting essentially of linear ultrahigh molecular weight polyolefin, a large proportion of finely divided water-insoluble filler of which at least about 50 percent by weight is siliceous, and interconnecting pores; and (b) a releasable active agent or precursor thereof associated with at least a portion of the filler.

Abstract: A substrate comprises a porous polymeric material having a porosity of at least 75% and comprising pores having a diameter within the range 1 to 100 .mu.m and being interconnected by a plurality of holes, and a gel or material adapted in use to form a gel which gel or pre-gel materials is contained and retained within the pores of the polymeric material and is adapted in use to interact with a reactive species and can be made by depositing and retaining the gel or a material adapted in use to form the gel within the pores of the porous polymeric material. The high porosity of the porous polymeric material in combination with the retention of the gel within the pores permit high loading capacities, particularly in the area of peptide synthesis to be achieved. The substrate can be employed in chemical synthesis, chromatography techniques, ion exchange and separation techniques.

Abstract: This invention relates to methods for porous resin moldings, for ultrafine fibers for ultrafine fiber nonwoven fabrics. In essence, the invention comprises providing a molding, spun fiber or crude nonwoven fabric containing a thermoplastic resin and a special high molecular compound which has an adequate affinity for the thermoplastic resin and able to dissolve rapidly in water and dissolving out the high molecular compound from the molding, spun fiber or crude nonwoven fabric. The method of the invention involve no risk of explosion or fire hazard in manufacture, free from adverse effects on health, and help curtail the manufacturing time.

Abstract: The resistance to discoloring of formed articles from polymer mixtures which comprise a polyphenylene ether and at least a second polymer can be improved by treating the surface of the formed articles with a solvent. The solvent is chosen so that the polyphenylene ether does dissolve therein, but the second polymer does not dissolve therein.

Abstract: Porous, rigid resin particles are prepared having a predetermined particle size distribution, surface area and porosity by polymerizing in the pores of porous inorganic template particles a reaction mixture comprising monovinyl monomers, polyvinyl crosslinking monomers and a polymerization initiator in a liquid medium in which the monomers and initiator are phase separable and extractable therefrom into the pores of the template particles. The extracted mixture is polymerized in the pores of the template particles, and the template particles are removed without destruction of the polymerizate. The isolated polymerizate mirrors the characteristics of the template particles. The surface of the polymerizate may be modified in various ways to contain desired functionality. The particles of the invention are useful in chromatography, adsorption, ion exchange, and in catalysis.

Abstract: A carbonized composite foam having a density less than about 50 mg/cm.sup.3 and individual cell sizes no greater than about 1 .mu.m in diameter is described, and the process of making it.

Abstract: An active agent delivery device comprises (a) microporous material comprising a matrix consisting essentially of linear ultrahigh molecular weight polyolefin, a large proportion of finely divided water-insoluble filler of which at least about 50 percent by weight is siliceous, and interconnecting pores; and (b) a releasable active agent or precursor thereof associated with at least a portion of the filler.

Abstract: A low density, open cell polymeric body is formed by coating or filling a reticulated polymeric foam with a liquid-form polymer which is resistant to high temperatures, curing the liquid form polymer in and on the foam and then removing the foam skeleton by dissolving and leaching the foam out of the solid polymeric body which remains.

Abstract: Microporous or open ultrafiltration poly (tetrafluoroethylene-co-perfluoro-(alkyl vinyl ether)) (PFA) or poly (tetrafluoroethylene-co-hexafluoropropylene) (FEP) film membrane or hollow fibers having open pores are formed from a melt blend of 10 to 35 weight percent of the PFA or FEP and a chlorotrifluoroethylene oligomer solvent. The melt blend is shaped and one or more surfaces of the shaped melt blend are coated with the solvent prior to phase separation of the melt blend. Coating the membrane with solvent during shaping results in membrane having larger pores on that membrane surface as compared to membranes not coated with solvent. The shaped melt blend is cooled to effect phase separation and crystallization of the PFA or FEP from the blend. The solvent is separated from the PFA or FEP by extraction and the porous PFA or FEP is heat set under restraint to prevent shrinkage.

Abstract: A porous polymeric material has cell sizes within the range 100 to 0.5 .mu.m and total pore volume with respect to the overall volume of the material in the range 75 to 98% and includes cross-linked polycondensation polymeric material. The material can be made from a high internal phase emulsion in which the cross-linked polycondensation polymer is formed in the continuous phase. The materials are preferably open interconnected cellular structures. They can be made of a wide range of polycondensation materials. The materials are thus highly porous and light weight and have a range of properties depending primarily on their constituent polycondensation materials.

Abstract: A dope for forming membranes and the resulting asymmetric gas separation membranes are disclosed, the membranes having graded density skins which exhibit improved permeability characteristics and increased failure pressure strength. The membranes are produced from a process utilizing membrane forming dopes of complexing solvent systems formulated from two non-solvents and one or more solvents. The non-solvents are chosen one each, from non-solvents grouped according to non-solvent strength, i.e., one strong non-solvent and one weak non-solvent which are combined with one or more solvents in an acid:base complex solvent system for dissolving high weight percent total solids of membrane forming polymers. The process for forming the membranes is also disclosed.

Abstract: A microporous polyetheretherketone (PEEK) membrane in the form of films and hollow fibers formed without sulfonating the PEEK polymer. Solid fibers and articles are also claimed. A method of making membranes, fibers and articles from solutions of PEEK in non-sulfonating acid solvents in claimed. Solvents include methane sulfonic acid and trifluoromethane sulfonic acid. Sulfuric acid may be used as a diluent in non-sulfonating amounts. PEEK membranes are used as supports for composite ultrafiltration and reverse osmosis membranes. A method of making membranes, fibers, and articles is also described.

Abstract: Microporous or open ultrafiltration poly (tetrafluoroethylene-co-perfluoro-(alkyl vinyl ether)) (PFA) or poly (tetrafluoroethylene-co-hexafluoropropylene) (FEP) film membrane or hollow fibers having open pores are formed from a melt blend of 10 to 35 weight percent of the PFA or FEP and a chlorotrifluoroethylene oligomer solvent. The melt blend is shaped and one or more surfaces of the shaped melt blend are coated with the solvent prior to phase separation of the melt blend. Coating the membrane with solvent during shaping results in membrane having larger pores on that membrane surface as compared to membranes not coated with solvent. The shaped melt blend is cooled to effect phase separation and crystallization of the PFA or FEP from the blend. The solvent is separated from the PFA or FEP by extraction and the porous PFA or FEP is heat set under restraint to prevent shrinkage.

Abstract: A process produces microporous powders or shaped articles, in particular membranes in the form of flat films, tubular films or hollow fibers, which may be used for controlled release of an active compound, for dialysis, gas separation, ultrafiltration or microfiltration, from polyvinylidene fluoride and/or polyphenylene sulfide and/or polysulfone and/or polyacrylonitrile and/or ethylene/vinyl alcohol copolymer and/or ethylene/chlorotrifluoroethylene copolymer and/or polyethersulfone and/or polyether-imide and/or polymethyl methacrylate and/or polycarbonate and/or cellulose triacetate. The process utilizes phase separation by means of thermally induced triggering or triggering induced by a non-solvent of a solution of the polymer in a mixture containing .epsilon.-caprolactam as the essential dissolving constituent. The solution may be formed before the phase separation is triggered.

Abstract: A substrate comprises a porous polymeric material having a porosity of at least 75% and comprising pores having a diameter within the range 1 to 100 .mu.m and being interconnected by a plurality of holes, and a gel or material adapted in use to form a gel which gel or pre-gel materials is contained and retained within the pores of the polymeric material and is adapted in use to interact with a reactive species and can be made by depositing and retaining the gel or a material adapted in use to form the gel within the pores of the porous polymeric material. The high porosity of the porous polymeric material in combination with the retention of the gel within the pores permit high loading capacities, particularly in the area of peptide synthesis to be achieved. The substrate can be employed in chemical synthesis, chromatography techniques, ion exchange and separation techniques.

Abstract: A method of manufacturing a porous membrane by dissolving vinylidene fluoride polymer in a good solvent such as acetone and then causing solidification of the resultant solution in a non-solvent. The dissolution of the vinylidene fluoride polymer in the solvent is done in a predetermined pressure condition, namely 0.1 kg/cm.sup.2, preferably in a range of 0.5 to 5.0 kg/cm.sup.2.

Abstract: An active agent delivery device comprises (a) microporous material comprising a matrix consisting essentially of linear ultrahigh molecular weight polyolefin, a large proportion of finely divided water-insoluble filler of which at least about 50 percent by weight is siliceous, and interconnecting pores; and (b) a releasable active agent or precursor thereof associated with at least a portion of the filler.

Abstract: The composition comprises polyolefins, fillers and a plasticizer. It contains 0.2 to 20 wt. % etoxysiloxane, 5 to 60 wt. % polyolefin, 10 to 60 wt. % white black filler, and 10 to 75 wt. % polyethyleneglycol, petroleum oil or dioctylphtalate. The polyolefin can be high-density polyethylene with a melt index at a standard charging up to 6, superhigh-molecular polyethylene, polypropylene, or a mixture of polypropylene and polyethylene, or of high-density polyethylene and super-high-molecular polyethylene at as ratio of 0 to 100 wt. parts high-density polyethylene for every 100 wt. parts super-high-molecular polyethylene. The composition is prepared by treating the filler with etoxysiloxane at room temperature, then adding the polyolefin and the plasticizer to form a mixture, and then homogenizing the mixture in a cold state or with heating. With this composition are prepared microporous separators having an average pore size of below 0.05.mu., and having high physicomechanical properties.

Abstract: A microporous particulate-filled thermoplastic polymeric article is provided. The article can be in the form of a film, a fiber, or a tube. The article has a thermoplastic polymeric structure having a plurality of interconnected passageways to provide a network of communicating pores. The microporous structure contains discrete submicron or low micron-sized particulate filler, the particulate filler being substantially non-agglomerated.

Abstract: A precipitation polymerization process for producing a macroporous cross-linked copolymeric lattice, capable of adsorbing hydrophilic and lipophilic fluids, in which process there is copolymerized at least one monounsaturated monomer and at least one polyunsaturated monomer in the presence of an organic liquid which is a solvent for the monomers but not for the copolymer, initiating the copolymerization of the monomers by means of a free radical generating catalytic compound, precipitating a copolymer in the solvent in the form of a powder, and forming a dry powder by removing the solvent from the precipitated copolymeric powder. One monomer is a hydrophilic compound and the other monomer is a lipophilic compound.

Abstract: A vehicle seat suspension has a thin high strength elastomeric membrane. The membrane is formed from block copolymer material by a process in which a sheet is extruded and tensioned to orient molecules in a select direction with respect to the membrane; the oriented membrane is annealed to retain the orientation during cyclical deformation of the membrane. The sheet form membrane is adapted to be connected with respect to a vehicle seat assembly frame and to serve as a backing for foam seating material and wherein the oriented structure of the membrane provides a two stage modulus in the direction of the orientation for providing static and dynamic load support characteristics which impart passenger comfort without increasing the weight of a seat assembly.

Abstract: Porous, rigid resin particles are prepared having a predetermined particle size distribution, surface area and porosity by polymerizing in the pores of porous inorganic template particles a reaction mixture comprising monovinyl monomers, polyvinyl crosslinking monomers and a polymerization initiator in a liquid medium in which the monomers and initiator are phase separable and extractable therefrom into the pores of the template particles. The extracted mixture is polymerized in the pores of the template particles, and the template particles are removed without destruction of the polymerizate. The isolated polymerizate mirrors the characteristics of the template particles. The surface of the polymerizate may be modified in various ways to contain desired functionality. The particles of the invention are useful in chromatography, adsorption, ion exchange, and in catalysis.

Abstract: Disclosed is new type of implantable material for replacement of cartilaginous or fibrous tissue. The material has controlled porosity and is biocompatible. A method for making this material is also disclosed.

Abstract: A process for producing hollow polymer latex particles, which comprises(1) adding a base to a carboxyl-containing polymer latex obtained by emulsion polymerization of a monomeric mixture composed of at least 0.1% by weight of an ethylenically unsaturated carboxylic acid and another ethylenically unsaturated monomer copolymerization with the carboxylic acid to adjust the pH of the polymer latex to at least 7 and swell the polymer latex particles, and(2) adding an acid to the polymer latex formed in (1) to adjust the pH of the latex to not more than 7.

Abstract: Microporous poly (tetrafluoroethylene-co-perfluoro (alkyl vinyl ether)) (PFA) or poly(tetrafluoroethylene-co-hexafluoropropylene) (FEP) membrane or hollow fibers are formed from a melt blend of 10 to 35 weight percent of PFA or FEP and a chlorotrifluoroethylene oligomer solvent. The melt blend is shaped and cooled to effect phase separation of the PFA or FEP from the blend. The solvent is removed from the PFA or FEP by extraction and the porous PFA or FEP is dried under restraint to prevent shrinkage.

Abstract: Microporous poly (tetrafluoroethylene-co-perfluoro (alkyl vinyl ether)) (PFA) or poly(tetrafluoroethylene-co-hexafluoropropylene) (FEP) membrane or hollow fibers are formed from a melt blend of 10 to 35 weight percent of PFA or FEP and a chlorotrifluoroethylene oligomer solvent. The melt blend is shaped and cooled to effect phase separation of the PFA or FEP from the blend. The solvent is removed from the PFA or FEP by extraction and the porous PFA or FEP is dried under restraint to prevent shrinkage.

Abstract: Disclosed is new type of implantable material for replacement of cartilaginous or fibrous tissue. The material has controlled porosity and is biocompatible. A method for making this material is also disclosed.

Abstract: Surgical sutures are provided that have an elastomeric and porous structure. The elastomeric porous structure can be formed from a plurality of fibers that are wound onto a stylet or onto an elongated and elastomeric central core of the suture, or from a mixture including elutable material that is cast into the configuration of a suture, either as a generally unitary cylinder or over an elongated and elastomeric central core of the suture.

Abstract: Asymmetric membranes are prepared by selectively treating a major surface of an incompatible polymer blend prepared by melt blending having at least one extractable polymer component and then contacting the polymer blend with a solvent to extract the extractable polymer component. The treated surface becomes the dense layer of the membrane. The major surface is treated by crosslinking, by contacting the surface with a crosslinking agent which is subsequently cured, or by contacting the surface with an agent which reacts with groups on the surface and imparts a polar character to it.

Abstract: This invention provides a method for the preparation of an article from a blend of at least two molecularly compatible polymers by treating the blend with a solvent which is a solvent for one of the polymers and a non-solvent for the other. The solvent can be removed while the article is restrained from undergoing substantial shrinkage, in which case a microporous article is obtained. Alternatively, the solvent can be removed while the article is permitted to shrink. In this case high shrinkage force (also referred to as recovery force) results which can be utilized to apply the article to a substrate. The final and intermediate articles are novel. In a preferred embodiment, the invention provides a microporous article having an average pore size of about 0.005 microns to about 1 micron.

Abstract: A hydrophilic porous membrane has graft chains of a hydrophilic monomer formed on the surface of a hydrophobic porous membrane so as to impart to the surface perfect hydrophilicity such that the produced membrane, when wetted, exhibits a swelling ratio of not more than 1% and a bubble point in the range of 0.5 to 8 kg/cm.sup.2. The hydrophilic porous membrane is produced by irradiating the hydrophobic porous membrane with plasma, feeding the hydrophilic monomer in a gaseous state, and allowing the hydrophilic monomer to be graft polymerized on the surface of the porous membrane. A plasma separator is obtained by using the aforementioned hydrophilic porous membrane as a plasma separation membrane.

Abstract: A process for preparing assymetric polyvinylidene fluoride microporous membranes using novel pore forming agents of an ammonium salt which is a non-solvent for the polymeric casting solution; such agents for example being ammonium hydroxide, ammonium chloride and the like.

Abstract: This invention relates to a process for the preparation of hydrophilic membranes by coagulation of a solution of at least one hydrophobic polymer and at least one hydrophilic polymer in a suitable solvent medium in a coagulation medium. The process according to the invention is characterized in that hydrophilic microfiltration and/or ultrafiltration membranes are prepared by cross-linking the hydrophilic polymer which is present in or on the obtained membrane matrix after the coagulation in an essentially non-swollen state and fixing same as such in or on the polymer matrix. Advantageously the solvents and the undesirable components of the coagulation medium are removed whereby the hydrophilic polymer is converted into an essentially non-swollen state prior to cross-linking. The removal of the undesirable components from the membrane takes place by means of a non-solvent for the hydrophilic polymer according to the invention.

Abstract: There is a growing demand for high molecular weight polyester resin. For instance, the market for high molecular weight polyethylene terephthalate resin is rapidly expanding. High molecular polyethylene terephthalate resin is currently being used in vast quantities in manufacturing bottles for carbonated beverages, trays for frozen foods which can be heated in either microwave ovens or convection ovens, and in tire cord. There is a growing trend toward higher molecular weights in many applications for such polyester resins. Unfortunately, it becomes progressively more difficult and expensive to produce polyester resins having higher and higher molecular weight utilizing standard commerical polymerization techniques. This invention discloses a technique by which polyester resin having extremely high molecular weight can be prepared utilizing a very rapid solid state polymerization process.

Abstract: A microporous membrane suitable for use in microfiltration. The membrane is a hydrophilic skinless sheet, formed of polytetramethylene adipamide, either alone, or in admixture with at least one other polyamide.

Abstract: A moisture permeable protector such as gloves, fingerstalls, etc. for protecting hands and fingers at workshop, etc. utilizing a polyurethane film which has excellent moisture permeability. The film is made of polyurethane polymer having a polyoxyethylene content of 15-62% in a polyesterpolyol having a molecular weight of 3000 or less. The moisture permeability (g/m.sup.2,24 hours) of the film is 1500 or higher per 45 micron thickness, and the water absorption swelling ratio is 30% or less.

Abstract: A process for preparing assymetric polyvinylidene fluoride microporous membranes using novel pore forming agents of an ammonium salt which is a non-solvent for the polymeric casting solution; such agents for example being ammonium hydroxide, ammonium chloride and the like.

Abstract: A process for preparing a porous random fiber polymeric composite sheet through the addition of a cellulose ether which is selectively soluble or insoluble to a random fiber composite slurry under conditions such that the cellulose ether is insoluble, forming the slurry into a sheet, fusing the organic polymer component of the sheet and heating the sheet to solubilize the cellulose ether whereby voids are formed in the sheet. Before the sheet is treated to remove the cellulose ether, it may be combined with other sheets and densified under heat and pressure. Before removing the cellulose ether, the densified sheet may be heated under reduced pressure to expand or loft the sheet in a direciton normal to the plane of the sheet. A random fiber polymeric composite sheet, a densified sheet and a lofted sheet, each comprising a binder, fusable organic polymer, reinforcing material and a cellulose ether are also provided. The same sheets after removal of the cellulose ether are further provided.

Abstract: Semipermeable membranes with improved permeation flux are prepared by contacting a glassy polymer in the form of a hollow fiber or film with a solvent in which the polymer swells at conditions which permit the swelling solvent to diffuse into the glassy polymer and then stretching the swollen polymer in an amount sufficient to cause visible stress whitening.

Abstract: Porous membranes of aromatic polymer (preferably ether ketone) are prepared with pore size and surface area allowing use in place of asbestos membranes in hot alkaline electrolysis cells. The membranes are prepared by solvent extraction of a polymer which is "partially incompatible" with the aromatic from a blend of the two. The membranes are preferably dried in the presence of a surfactant to enhance re-wetting in use.

Abstract: A membrane for selectively separating gases having high and selective permeability for oxygen and sufficient strength which is capable of extracting and concentrating oxygen in a mixed gases, especially in the air, and is produced from a novel poly(disubstituted acetylene)/polyorganosiloxane graft copolymer where the main chain is composed of poly(disubstituted acetylene) and the side chain is composed of polyorganosiloxane, and the copolymer.

Abstract: The present invention provides a process for manufacturing a porous polymer containing many voids in its interior, which has a small apparent specific gravity and is superior in terms of water absorbing properties, permeability and elasticity. The process comprises (1) forming O/W emulsion by using a water soluble surfactant wherein an inner phase of the O/W emulsion is a hydrophobic phase and an outer phase thereof is a water phase containing at least one water-soluble polymerizable monomer; (2) adding said O/W emulsion to a hydrophobic dispersing medium containing an oil-soluble surfactant to form O/W/O emulsion; and (3) polymerizing the monomer.

Abstract: An expansible macromolecular material is produced by a method which comprises mixing an aqueous polyvinyl alcohol solution, an acidic aqueous macromolecular electrolyte solution, and a basic aqueous macromolecular electrolyte solution thereby preparing a composite polymer and subjecting this composite polymer to at least one cycle of alternate freezing and defrosting treatments. A macromolecular membrane constituted of said expansible macromolecular material and containing numerous through holes is obtained by mixing, freezing, and defrosting the aforementioned three mixed aqueous solutions under specific conditions.