Abstract: Process for the production of porous, powdery polypropylene, and utilization thereof. Hot solutions of polypropylene in pentaerythrol ester are slowly cooled down to approximately room temperature, forming a solidified mass, after which it is extracted with an extractant in which pentaerythrol is soluble. Before extracting, the size of the solidified mass may be reduced mechanically. After extracting, the pentaerythrol may be removed from the extractant to a high degree. Preferred embodiments include using solutions of polypropylene in pentaerythrol esters of fatty acids, more specifically, of synthetic fatty acids with 8-10 carbon atoms; using ethanol for the extraction; using solutions with a weight ratio of polypropylene to pentaerythrol ester of 30:70 to 10:90; having cooling of the solutions within the range of 260.degree. to 120.degree. C. proceed at an average rate of 1.degree. to 20.degree. C. per minute; using polypropylene with an admixture of up to 10% by weight of polyethylene.

Abstract: This invention relates to a process of preparing aqueous slurries of vesiculated granules of crosslinked polyester resin wherein the granules have a maximum shrinkage on drying of 5% of the granule diameter. Previously-known processes for the preparation of granules of this type have utilized polyamines; this has led to odor and color problems. These problems may be eliminated or substantially reduced by the use of bases which are metal oxides, hydroxides or salts wherein the metal cation is selected from Ca, Mg, Ba, Ti, Zn, Pb, Sr and Co and, when a metal salt is used, the pKa value of the conjugate acid of the anion is greater than 2. The resulting granules are useful at matting and opacifying agents in, for example, paint compositions.

Abstract: Aqueous emulsions of unsaturated polyester resins comprising two "air-drying" polyesters, one polyester containing co-condensed polyalkylene glycol residues and the other polyester being free from groups such as these, can be hardened uniformly and relatively quickly to form tack-free, open-pore coatings, even on exotic woods.

Abstract: A process for preparing a porous material having a fine pore size which comprises preparing a solution comprising resin comprising a vinylidene fluoride/tetrafluoroethylene copolymer, a vinylidene fluoride polymer or a mixture thereof and at least a solvent for the resin and a non-solvent for the resin, and removing the solvent and the non-solvent from the solution, wherein a part of the resin is dissolved or swollen during the removal of the solvent and non-solvent.

Abstract: A process of manufacturing a microporous sheet by forming a blend of a polyolefin, silica and a water insoluble plasticizer, forming a sheet from the blend, and contacting the sheet with water for a time sufficient to render the sheet microporous. The plasticizer, being essentially insoluble in water, is easily separated therefrom and recycled. The preferred plasticizers are dialkyl phthalates and dialkyl adipates having between about two and about eleven carbon atoms in the oxo-alcohol moiety.

Abstract: As an article of manufacture, a microporous flexible shape or sheet of a sulfur-free, cured polymeric material of a curable rubber, an ethylene-propylene copolymer or mixtures of the curable rubber and ethylene-propylene copolymer; the article possesses an average pore size of less than 2 microns, a predetermined flexibility, and improved toughness, when compared to prior art sulfur cured articles.

Abstract: A membrane made of a composition containing essentially two kinds of ethylene-vinyl alcohol copolymers with different ethylene unit contents and the membrane has such a microstructure that there are at least one active layer and a porous layer thereunder, the porous layer comprises mono- or multi-layer of a plurality of cylindrical voids and a plurality of spherical voids therein and the membrane is of a porosity of 70 to 95%.

Abstract: Novel plated compositions are disclosed which include a polyphenylene ether resin, a small-particle EPDM rubber-modified alkenyl aromatic resin, and a hydrogenated A-B-A block polymer. Also included within the scope of this invention are reinforced and flame-retardant compositions of said polyphenylene ether resin, said alkenyl aromatic resin modified with an EPDM rubber, and said hydrogenated elastomeric block copolymer.

Abstract: A sheet material with improved dyeability comprises a polyurethane resin obtained by reacting an organic diisocyanate with a polymer polyol and if necessary together with a chain extender.

Abstract: A method is provided for making microporous, vapor-permeable polyurethane sheets by coagulating a polyurethane in a polar solvent with a non-solvent for the polyurethane, wherein a polyurethane polysiloxane is added to the solution of the polyurethane in the polar solvent.

Abstract: Aqueous slurries of vesiculated cross-linked polyester resin granules which show a shrinkage of less than 5% on drying are prepared by a double-emulsion process in the presence of polyamine having a pKa value of 8.5-10.5 at a concentration of 0.3 to 1.4 amine groups per carboxyl group of the polyester, the acid value of which is limited to 10-45 mgm KOH per gm.The granules are of particular use as opacifying matting agents in latex paints and avoid the defect observed hitherto of cracking at high film builds.

Abstract: An ion-exchange membrane is formed from a solution containing dissolved matrix polymer and a set of monomers which are capable of reacting to form a polyquaternary ion-exchange material; for example vinyl pyridine and a dihalo hydrocarbon. After casting the solution and evaporation of the volatile components, a relatively strong ion-exchange membrane is obtained which is capable of removing anions, such as nitrate or chromate from water. The ion-exchange polymer forms an interpenetrating network with the chains of the matrix polymer.

Abstract: There is disclosed a novel process and product produced thereby for the selective stretching of incremental portions of a substrate of a synthetic thermoplastic material selected from the group consisting of a thermoplastic orientable polymer or a blend of a thermoplastic orientable copolymer in which there is admixed an incompatible second phase selected the group consisting of an incompatible polymer or inorganic material. The substrate is stretched in grooved roller pairs by controlling the velocity of introduction of the substrate to maintain the velocity substantially identical to the surface velocity of the roller pair. Stretching of the blends produce an opaque, low density porous sheet.

Abstract: The invention relates to a semi-permeable membrane for a lead-acid battery. The membrane has a microporous structure comprising a first polymer and a second polymer intimately mixed together, and is characterized by the fact that the first polymer is chosen from among the following polymers: polyacrylic acid, polymethacrylic acid, a copolymer with a high proportion of acrylic or methacrylic acid, a mixture of these polymers, the average molecular weight of these polymers lying between 10,000 and a few millions and preferably between 50,000 and one million, the second polymer being soluble in water.

Abstract: New solvents have been found for certain poly(parabanic acids) and poly(iminoimidazolidinediones). Epihalohydrins and glycidyl acrylate have been found to be solvents. Cellular films are produced by immersing films of the polymer solutions in aprotic anti-solvents such as aliphatic ketones, esters, hydrocarbons, halogenated hydrocarbons and ethers.

Abstract: A process for the preparation of an ion exchange resin of higher porosity and purity is described. The porosity is achieved by inserting polar, preferably hydrolyzable linear polymer into the polymerizing phase. The insert is later extracted from the polymerized beads.