摘要:
Described is a method for preparing a polybenzazole filament which comprises extruding a polybenzazole dope filament, drawing the filament across an air gap, coagulating and washing the filament, and drying the filament, characterized in that a solution of a compound selected from the group consisting of ferrocenes, ruthocene, iodide-, cobalt-, and copper-containing compounds, dyes, and mixtures thereof is contacted with a filament subsequent to the washing step and prior to the drying step. This method provides a means to improve the tensile strength retention of damaged polybenzazole filaments following exposure to sunlight.
摘要:
This invention relates to a low heat release, low density, fiber-reinforced composite comprising a matrix comprising a thermoplastic polymer selected from the group consisting of polyarylsulfone, polyethersulfone, polyetheretherketone, polyetherketoneketone, a copolycarbonate of 4,4'-thiodiphenol and at least one member of the group consisting of bisphenol A, 9,9-bis(4-hydroxyphenyl)fluorene, and 1,1-bis(4-hydroxyphenyl)-1-phenyl ethane, a copolycarbonate of bisphenol A and 9,9-bis(4-hydroxyphenyl)fluorene, 1,1-bis(4-hydroxyphenyl)-1-phenyl ethane polycarbonate, bisphenol A polycarbonate, and polyetherimide, and from about 10 to about 70 percent by weight of the composite of randomly oriented reinforcing fibers, less than 0.5 inch in length, distributed throughout the matrix. The matrix has a void volume of from about 20 to about 90 percent by volume. The composite has a thermoplastic skin layer on each of the major surfaces thereof. A process for making the composite is also disclosed.
摘要:
Fibers may be prepregged with a dope containing polybenzoxazole or polybenzothiazole. The prepreg may be contacted with water or another nonsolvent to coagulate the polymer and form a matrix composite.
摘要:
Stable, aqueous emulsion formulations of water-insoluble organic pesticides are formed from a mixture of (1) a water-insoluble organic pesticide, (2) a water based structured particle latex containing nonionic particles to which is bound a layer containing stabilizing pH independent ionic groups chemically bound at or near the surface of the polymer particles, and optionally a cosolvent and/or a cosurfactant for the pesticide. The resulting product is much more stable to coalescence than emulsions made with conventional surfactants.
摘要:
Pulps and short fibers containing polybenzoxazole and/or polybenzothiazole or copolymers thereof can be synthesized by freezing the wet fiber straight from the coagulation bath without drying, and chopping or grinding the frozen fiber to the desired size and degree of fibrillation.
摘要:
Microporous, asymmetric membranes comprising syndiotactic vinylaromatic polymers having utility as membranes for ultrafiltration or reverse osmosis and a process for their production.
摘要:
Structured particle latexes contain organic polymer particles in aqueous media having a nonionic core encapsulated by a thin layer of a water-insoluble copolymer containing pH independent stabilizing anionic groups such as sulfonate groups chemically bound at or near the particle surface.
摘要:
Substantially linear, synthetic, water-soluble or water-dispersible cationic interpolymeric surfactants which are particularly useful for reducing the surface tension of an aqueous medium; such surfactants having a critical micelle concentration of from 0.01 to about 10 percent in water at 25.degree. C., a charge density of from about 1 to 5 meq/g and a number average molecular weight of from about 500 to about 40,000 and being composed of a plurality of nonionic hydrophobic units and pH independent hydrophilic cationic units randomly distributed in the backbone of such interpolymeric surfactants and wherein an average molecule of such surfactant contains from 1 to about 5 hydrophilic cationic units substituted with a pendant hydrophobic group, such hydrophobic group being an alkyl or aralkyl group of from about 8 to about 20 carbon atoms are prepared by (1) aqueous, emulsion polymerization of a mixture of ethylenically unsaturated nonionic monomers at least one of which contains an ion-forming group in the presence of a copolymerizable monomeric surfactant to form a latex, (2) reacting the resulting latex with a coreactant to form a water-soluble cationic interpolymer.
摘要:
A fibrous product containing (a) a papermaking grade of pulp, (b) a structured particle latex having pH independent cationic groups bound at or near the particle surface and (c) a co-additive. The pulp is represented by unbleached softwood kraft. The latex is represented by a structured-particle latex having (a) a core of a copolymer of styrene and butadiene (b) an encapsulating layer of styrene, butadiene and vinylbenzyl chloride which is reacted with 2-(dimethylamino) ethanol to form quaternary ammonium groups. The co-additive is represented by a hydrolyzed polyacrylamide having a degree of polymerization of 5500. To an aqueous slurry of the pulp are added the latex and an aqueous solution of the co-additive, the resulting suspension is dewatered and dried by heating.
摘要:
An improvement in the process of forming plastic articles wherein such articles are forged from a compression formed briquette of resinous powder, such improvement comprising (1) compressing a resinous powder having lamellar crystalline nonspherulitic morphology into a substantially unoriented briquette having green strength, (2) removing the briquette from the compressing device and placing the briquette in a forging press wherein lubrication is provided between the contacting surfaces of the briquette and the forging press to permit plug flow, and (3) forging the briquette into a shaped article while maintaining the briquette at a temperature between the alpha-transition temperature and the melt temperature of the resinous powder.