Abstract: The invention relates to dry-spun polyacrylonitrile filament yarns having a tensile strength of at least 47 cN/tex and an individual filament denier of at most 1.5 dtex and preferably an overall denier of 20 to 145 tex as well as to a process for the production thereof by spinning, hot drawing and relaxing, wherein the spun filaments are drawn during spinning to such an extent that, after subsequent hot drawing in a ratio of from 1:6 to 1:10 and relaxation, the individual filaments have a denier of at most 1.6 dtex.

Abstract: This invention relates to a process for emulsion polymerization of a vinyl monomer in an aqueous dispersion medium in which a salt of an N-acylsarcosine and an alkali metal salt and/or ammonium salt of an oxyacid are made to coexist with each other.

Abstract: A process for the free radical polymerization of vinyl monomers, including vinyl aromatic monomers, wherein the temperature of the polymerization is progressively increased by at least 30.degree. C during the period of the polymerization a temperature range of from 50.degree. C to 160.degree. C and wherein the final temperature is at least 110.degree. C, the polymerization mass including an initiator sensitive to produce free radicals near or at the low temperature end of the range and an initiator sensitive to produce free radicals near or at the high temperature end of the range. A single entity initiator may contain peroxide functions that are actuated to produce free radicals at each of the temperature extremes of the process.

Abstract: A method of preparing cross-linked hydrogels in the form of shaped articles, insoluble in any solvent but swellable in water and in aqueous liquids, is provided. The method comprises polymerizing acrylonitrile alone or with a minor amount up to 15% by weight of monoethylenically unsaturated monomers copolymerizable with acrylonitrile under conditions of radical polymerization in concentrated, i.e. 50 to 72%, nitric acid in the absence of any added chain-transfer and cross-linking agents, said monomer or monomers being used in concentrations making possible cross-linking by chain transfer onto the monomer, i.e. in concentrations ranging from 15 to 50%, preferably from 25 to 40% by weight, at temperatures ranging from 0.degree. to 50.degree. C, preferably from 5.degree. to 20.degree. C. The polymerization is carried out in a mold.

Abstract: This specification discloses an insoluble resin-metal compound complex, the method for its preparation, and its use in carrying out a catalyzed reaction. The complex is a weak base anion exchange resin which has been contacted with a solution of a coordination compound having at least two ligands connected to at least one central metal atom to bond chemically the resin to the metal atom by replacement of at least one of the ligands of the coordination compound by a functional group of the weak base anion exchange resin. The complex can be used as a catalyst for hydrogenation, carbon monoxide insertion, polymerization, isomerization, vinyl ester exchange, and ethylene oxidation reactions, among others.

Abstract: The invention relates to highly shrinkable fibres or filaments of acrylonitrile polymers or copolymers which have a shrinkability of at least 35% and a fibre strength of at least 2 p/dtex.The invention relates further to a process for the production of these fibres or filaments.

Abstract: In the polymerization of at least one ethylenically unsaturated monomer other than vinyl chloride, deposition of polymer scale on the inner walls of a polymerization reactor and other surfaces coming into contact with the monomer is effectively prevented (regardless of the type of polymerization used, so long as it takes place in a heterogeneous phase) by coating the surfaces of the reactor with at least one compound selected from organic electron donor compounds and organic electron-acceptor compounds prior to polymerization; the compound or compounds having been or being brought into contact with an oxidizing agent, a reducing agent, an acid or a base, or having been or being irradiated with ultraviolet light.

Abstract: Ethylenically unsaturated monomers susceptible to free radical polymerization may be polymerized by contacting the monomers with an initiating compound having the formula: ##STR1## wherein R.sub.1 is a substituted or unsubstituted aryl radical.

Abstract: Nitrile polymers are prepared in a polymerization reaction wherein 1,4-cyclohexadiene or a selected derivative thereof is used as a chain transfer agent.

Abstract: An improved process for producing an acrylonitrile melt by polymerizing acrylonitrile alone or a monomer mixture consisting of at least 75% of acrylonitrile and as the remainder at least one different ethylenically unsaturated compound in a system where water is present in an amount from 3 to 80% by weight based on the total amount of the monomer(s) and water, under a pressure above the self-generated pressure at a temperature above 80.degree. C. The improvement is characterized by the use of hydrogen peroxide as the polymerization initiator.

Abstract: Organosulfur molecular weight regulators for emulsion polymerization systems, such as mercaptan compounds, are mixed and agitated with the aqueous emulsifier prior to use in emulsion polymerization systems. The modifying efficiency of the organosulfur molecular weight modifiers can be controlled by the degree of agitation. In many cases, adding the agitated mixture incrementally to the emulsion polymerization system further improves effectiveness of the modifier.

Abstract: Initiating compounds having the following formula: ##STR1## wherein R.sub.1 in an substituted or unsubstituted aryl radical and wherein R.sub.2 is hydrogen or alkyl are useful in initiating polymerization reaction of ethylenically unsaturated monomers susceptible to free radical polymerization.

Abstract: The invention relates to anionic polymerization and copolymerization of methacrylate and acrylate esters and related polar monomers, e.g. acrylonitrile, by initiation with carboxylic acid esters formally substituted in the .alpha.-position with Li, Na, K, Rb or Cs and containing 3 - 30 C atoms in the straight or branched chain and 1 - 6 ester group in one molecule either alone or in the presence of C.sub.3 - C.sub.16 alkali metal alkoxide with the straight or branched chain. The polymerization or copolymerization is carried out at -80.degree. to +50.degree. C, advantageously at 20.degree. C and the molar ratios of monomers to .alpha.-metallo ester 10 to 1500 and alkoxide to .alpha.-metallo ester 0.5 to 80. Instead of the pure isolated .alpha.-metallo esters also a reaction mixture may be used which was prepared from the alkaline salt of substituted organic amide and non-metallated ester.

Abstract: Iodine or organic iodides are effective in suspension polymerization systems as molecular weight regulators or modifiers. These modifiers are especially suited for the suspension ABS processes.

Abstract: This invention relates to the production of spinnable solutions of acrylonitrile homopolymers or acrylonitrile copolymers in which the polymerization is conducted in an organic solvent containing a catalyst system comprising an acid, e.g., sulfuric acid, a peroxodisulfate, e.g., ammonium peroxodisulfate, and a 1,3-diketone, e.g., acetyl acetone. Polymers having a good natural color and high K-values are obtained in good yields.

Abstract: The present invention relates to a process for the polymerization of acrylonitrile or a monomer mixture containing acrylonitrile as a main component and at least one other ethylenically unsaturated compound, characterized in that the polymerization is conducted at a temperature above 120.degree. C. under a pressure above the vapor pressure generated in the polymerization system under the polymerization conditions in a system in which water is present in a range of 3 to 50 percent by weight based on the total weight of the monomer(s) and water to produce an acrylonitrile polymer in a substantially molten state. The polymers produced according to the above process have the advantage of being able to be directly shaped by extrusion without the need of solvents.

Abstract: A method for the anionic polymerization of unsaturated monomers involves effecting reaction in the presence of an organic derivative of a metal alumina hydride in an amount ranging from 0.01 to 5.0 mol percent based upon the amount of unsaturated monomer.

Abstract: Adducts of hydrocarbon lithium compounds and alkadienols such as 2,4-pentadien-1-o1 are employed in the anionic solution polymerization of polymerizable monomers to produce polymers containing terminal hydroxyl groups.

Abstract: A reinforcing composition for mineral structures which comprises as reactive ingredients one or more radical-polymerizable or copolymerizable monomer and a bisulfite ion-supplying substance. The use of the reinforcing composition facilitates reinforcement of natural or artificial mineral structures and products.

Abstract: Primary-aliphatic-.alpha.-hydroxyazo-alkanes having the structure: ##STR1## wherein R is hydrogen or a hydrocarbon radical containing 1 to 18 carbon atoms;R.sup.1 is the same as R except R.sup.1 is not hydrogen;R.sup.2 is the same as R except R.sup.2 is neither hydrogen, aryl, nor alkaryl;R.sup.1 and R.sup.2 can together form an alkylene diradical;R, r.sup.1 and R.sup.2 may be optionally substituted with the same or different groups.The compounds of the invention are more stable than the corresponding tertiary aliphatic-alpha-hydroxyazoalkanes. The compounds of the invention are useful as foaming agents for polyester resins and initiators for free radical polymerization of vinyl monomers.

Abstract: A time-lapse free-radical polymerizable composition which comprises (1) a free-radical polymerizable compound such as an ethylenically unsaturated monomer or a reactive polymer; (2) a soluble polymerization initiator such as a diacyl peroxide, a ketone peroxide; an alkyl peroxy ester, a dialkyl peroxide, or an inorganic persulfate; (3) a soluble, reducible metal chelate such as an iron or copper chelate in which the chelating agent is a .beta.-dicarbonyl compound having an enol content of at least 4 percent and a dicarbonyl angle of not greater than 120.degree., or a .beta.-hydroxy nitrogen-heterocyclic fused aromatic in which the hydroxyl group is attached to a carbon beta to the nitrogen in an adjacent ring; (4) a soluble organic reducing agent which is capable of reducing ferric ions to ferrous ions or cupric ions to cuprous ions; and (5) excess chelating agent in the amount of 10.sup.-.sup.4 to 2.5 moles of excess chelating agent per mole of reducible metal chelate.

Abstract: Acrylonitrile polymers of improved whiteness and thermal stability are provided by polymerizing acrylonitrile alone or with a comonomer in an aqueous medium, in the presence of a water-insoluble mercaptan, together with a redox catalyst comprising sulfurous acid or a salt thereof and nitrous acid or a salt thereof.

Abstract: An improved process for the wet-spinning of acrylic polymers is disclosed, wherein a spinning solution of an acrylic polymer in an organic solvent, such as dimethylacetamide or dimethylformamide, is extruded through a spinneret into a coagulating bath consisting essentially of water and an organic solvent in a ratio between 30:70 and 60:40 by weight, and wherein the filaments thus obtained are washed, stretched and heat treated, and wherein the coagulating bath contains from 0.03% to 3% by weight of acid corresponding to said organic solvent and has a pH value greater than 5, and preferably between 6.5 and 8. The spinning solvent is preferably dimethylacetamide containing free acetic acid to an extent of less than 0.1% by weight, the acetic acid if necessary being added to the coagulating bath to bring its concentration up to values between 0.03% and 3% by weight. The pH value greater than 5 is obtained by the addition to the coagulating bath of ammonium hydroxide, an alkali metal hydroxide, or dimethylamine.

Abstract: A new compound, 2-[(1-cyano-1-methylethyl)azo]-2-methylpropionamide, has been found which is useful as an initiator in the polymerization of ethylenically unsaturated compounds.

Abstract: A method of measuring the extent of an exothermic chemical reaction while the reaction is proceeding which comprises measuring the difference between the ingoing and outgoing temperatures of a coolant passing through the reaction vessel and computing therefrom the heat produced by the reaction, and in which the numerical value of the temperature of the ingoing coolant is retained in a memory device before being compared with that of the outgoing coolant, the period of retention being equal to the time taken for coolant to pass from the point of measurement of the ingoing temperature to the point of measurement of the outgoing temperature. This corrects errors due to variations with time of the temperature of the ingoing coolant.

Abstract: Liquid mixtures of symmetrical and asymmetrical azonitriles are provided which have a maximum freezing point of 25.degree. C. including mixtures of:A. 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2-methylhexanonitrile) and 2-[(1-cyano-1-methylpropyl)azo]-2-methylhexanonitrile;B. 2,2-azobis(2-methylbutyronitrile), 2,2'-azobis(2-methylheptanonitrile) and 2-[(1-cyano-1-methylpropyl)azo]-2-methyl-heptanonitrile;C. 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2-ethylhexanonitrile) and 2-[(1-cyano-1-methylpropyl)azo]-2-ethylhexanonitrile;D. 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2-ethylheptanonitrile) and 2-[(1-cyano-1-methylpropyl)azo]-2-ethylheptanonitrile;E. 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2-methyloctanonitrile) and 2-[(1-cyano-1-methylpropyl)azo]-2-methyloctanonitrile;F. 2,2'-azobis(2-methylpentanonitrile), 2,2'-azobis(2-ethylhexanonitrile) and 2-[(1-cyano-1-methylbutyl)azo]-2-ethylhexanonitrile;G.

Abstract: Polyazo compounds containing at least one alkyl or aryl thia or oxa group alpha to at least one of the azo groups in the connecting chain between the azo groups, such as 4-t-butylazo-4-methyl-3-thiapentyl 4-t-butylazo-4-cyanovalerate, which are useful for the sequential generation of free radicals, especially in the preparation of block and graft copolymers.

Abstract: The invention relates to a process for the recovery of acrylonitrile and other monomers from an aqueous polymer dispersion by continuous distillation in a thin-layer evaporator under reduced pressure, condensation of the evaporated monomers in a condenser under the same or similar reduced pressure and subsequent condensation or absorption respectively of the monomer vapors which have not been condensed in the condenser at a higher pressure.

Abstract: The invention relates to a process for the production of polyacrylonitrile tows containing from 7 - 15 % by weight, preferably from 10 - 12 % by weight, of comonomer components from which it is possible to produce yarns having low boiling-induced shrinkage values and yarns and dimensionally stable made-up articles with improved textile properties which comprises reducing the tow-shrinkage emanating from the spinning and stretching process by 80 - 95 % of the original tow shrinkage by heat-fixing and eliminating subsequently the residual shrinkage by fixing with saturated steam.

Abstract: Photopolymerizable compositions consisting essentially of at least one polymerizable ethylenically unsaturated material and a photosensitive catalyst comprisingA. from 0.5% to 5% by weight based on the ethylenically unsaturated material of at least one photosensitizer having the structure ##EQU1## wherein Ph is phenyl, halogen-substituted phenyl, phenylene or halogen-substituted phenylene and A is a cyclic hydrocarbyl group, a halogen-substituted cyclic hydrocarbyl group or a group of the formula ##EQU2## where X and Y each is hydrogen, a hydrocarbyl or a halogen-substituted hydrocarbyl group, andB. from 1 to 5% by weight based on the ethylenically unsaturated material of a reducing agent capable of reducing the photosensitizer when the photosensitizer is in an excited state.Also described is a process of preparing polymeric materials by irradiating the foregoing polymerizable composition at a wavelength capable of exciting the photosensitizer to an excited state.

Abstract: A photopolymerizable composition comprising a polymerizable ethylenically unsaturated material and a photosensitizer, said photosensitizer being an addition product of an organic 1,2,3-triketone and an organic alcohol or organic mercaptan, said addition product having the formula ##EQU1## or ##EQU2## where the groups R and R.sub.1 may be same or different and each is a hydrocarbyl group or a substituted hydrocarbyl group or the groups R when taken together form part or the whole of a cyclic structure.

Abstract: The reaction product of a chromium tris-diorgano-orthophosphate and an alkyl aluminum halide is a catalyst for olefin polymerization and for alkylation of aromatic hydrocarbons with olefins.

Abstract: Sulphur dioxide and unreacted monomer or mixture of monomers are separated and recovered from the polymer or copolymer slurry obtained by polymerizing acrylonitrile monomer or copolymerizing acrylonitrile monomer and a further ethylenically unsaturated monomer copolymerizable therewith in the presence of a catalytic system comprising sulphur dioxide or a sulphite, by a process comprising the steps of separately removing the sulphur dioxide and the monomer or mixture of monomers from the slurry in two distinct volatilization zones connected in series under decreasing subatmospheric pressures, scrubbing with water the sulphur dioxide vapors removed in the first zone and vapors of unreacted monomer or monomers removed in the second zone, and recycling the two resulting aqueous solutions to the polymerization or copolymerization medium.

Abstract: Organometallic compounds of high carbanion yield are prepared by metallation with barium, strontium or calcium or mixture of the same of certain acidic organic compounds having a pKa value of between about 15 and 35 on the MSAD scale in the presence of aprotic polar solvents, e.g., barium reacted with xanthene in 1,2-dimethoxyethane to yield dixanthenyl barium. Such organometallic compounds formed by metal-hydrogen exchange reaction are useful in initiating anionic growth-type polymerization of monomers, e.g., alkylene oxides and vinyl compounds, to form homopolymers and copolymers. The persistence of polymer carbanions created by such catalysts makes possible the controlled preparation of a variety of polymers, including block copolymers.

Abstract: The mono- or diester of phosphoric acid and a straight chain alkanol of 8 to 10 carbon atoms is used as a surfactant in the emulsion polymerization of olefinic compounds, especially vinyl compounds, to obtain polymers having improved stability to light and heat.

Abstract: (Hydrocarbon-peroxy hydrocarbon) phosphonates, useful as polymerization initiators, prepared by the reaction of a hydroperoxide with a phosphonate of an unsaturated hydrocarbon may be used to polymerize acrylic monomers.

Abstract: Polymer deposit or build-up on the interior surfaces of a polymerization vessel during polymerization of monoethylenically unsaturated monomers in aqueous dispersion may be inhibited by adding certain heterocyclic compounds to the dispersion prior to polymerization.

Abstract: A process for polymerizing acrylonitrile monomer or copolymerizing a mixture of acrylonitrile monomer and further ethylenically unsaturated monomers copolymerizable therewith, which comprises contacting the monomer or mixture of monomers in an aqueous medium at a temperature not exceeding 55.degree.C with a catalytic system comprising a watersoluble persulphate, a hydroxylamine mono- or disulfonate and a water-soluble salt of a variable valence metal, such as a ferrous salt.

Abstract: Aqueous dispersions of synthetic polymers have been made by polymerizing ethylenically unsaturated monomers in water in the presence of a protective colloid which is a polymer of a hydroxyalkyl acrylate or methacrylate. Such aqueous dispersions are useful in paints, adhesives and textile applications.

Abstract: The invention is concerned with the effecient removal and recovery of unreacted monomers from polymer latices prepared by emulsion polymerization.

Abstract: A continuous process for the polymerisation of olefinically unsaturated monomers in bulk or in solution in which at least a portion of the low-viscosity materials to be fed to the polymerization zone is thoroughly mixed with a portion of the high-viscosity contents of the polymerization zone in a mixing zone disposed upstream of the polymerization zone, which mixture is then continuously fed to the polymerization zone. The resulting polymers have a uniform composition and a narrow molecular weight distribution. They may be converted to shaped articles by thermoplastic methods.