Cyclopolymerization protocol for the synthesis of a poly(zwitterion‐alt‐sulfur dioxide) to investigate the polyzwitterion‐to‐poly(anion‐zwitterion) transition

The zwitterionic monomer, 3‐(N,N‐diallyl,N‐carboethoxymethylammonio)propanesulfonate, on cocyclopolymerization with sulfur dioxide in DMSO using azoisobutyronitrile as the initiator afforded the polyzwitterion (PZ) copolymer in excellent yields. The PZ on acidic hydrolysis of the ester groups led to the corresponding polyzwitterionic acid (PZA). The pH‐responsive PZA on treatment with sodium hydroxide gave the new poly(eletrolyte‐zwitterion) (PEZ). The solubility, viscosity behaviors, and solution properties of the salt‐tolerant PZ, PZA, and PEZ were studied in detail. Like common PZs, PZ was found to be insoluble in salt‐free but soluble in salt‐added water. The apparent basicity constants of the carboxyl group in PEZ have been determined. As the name implies, the PEZ possesses dual type of structural feature common to both conventional anionic polyelectrolytes and PZs, and its aqueous solution behavior is found to be similar to that observed for a typical alternating anionic‐zwitterionic copolymer. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Alkaline hydrolysis of nitrile groups in hydrazided nitron fibre

Conclusions The process of alkaline hydrolysis of nitrile groups in hydrazided Nitron fibre has been studied. It has been shown that introduction of hydrazidine groups into the polymer chain catalyzes the alkaline hydrolysis process because of a change in the basicity of the polymer chain.A cation-exchange VION KN-1 fibre has been prepared with higher physico-mechanical properties, which still retains satisfactory sorptive properties.Translated from Khimicheskie Volokna, No. 3, pp. 7–8, May–June, 1988.     

Preparation of heat-stable polypropylene fibres and their properties

Conclusions A method has been developed for preparing a modified polypropylene fibre by spinning from a mixture of polypropylene and a small amount of a thermoplastic acrylonitrile copolymer which contains a functional group which forms intermolecular chemical bonds during the fibre preparation process.It has been shown that in the given method of modifying PP fibre, its heat resistance is raised by 40–50°K.Translated from Khimicheskie Volokna, No. 3, pp. 51–52, May–June, 1985.     

Sorption of hydrogen sulfide by VION anion-exchange fibres

Conclusions The effect of the basicity of the chemically active groups in chemisorptive fibres on their sorptive properties with respect to hydrogen sulfide has been demonstrated.In the regeneration of fibrous sorbents with alkali solutions, it is advisable to use weakly basic fibrous sorbents for the absorption of hydrogen sulfide.Translated from Khimicheskie Volokna, No. 6, pp. 10–11, November–December, 1988.     

Spinning of a chemisorptive sulfonic acid fibre

Conclusions Special features of spinning a fibre by the wet method from a copolymer based on acrylonitrile and sodium methallylsulfonate which are connected with dissociation and solvation of the sulfonate groups have been examined.It has been found that, to obtain a fibre with satisfactory physico-mechanical properties which assure processing into textile articles from a sulfonate-containing copolymer, it is necessary to carry out the spinning either into nonaqueous baths or into aqueous baths which contain lyophilic salts.Translated from Khimicheskie Volokna, No. 3, pp. 10–12, May–June, 1988.     

Service of refractory concretes in the lining of steel-teeming ladles

Conclusions An investigation of the temperature and slag regimes of concrete linings has shown that one half of the lining's thickness, the one on the metal melt side, is subjected to severe cyclical changes in temperature, whereas the other half operates under steady thermal conditions throughout the furnace campaign.It has been established that cooling of the lining with water sharply reduces the temperature of the contact layer of the lining, i. e., it leads to thermal shock with accompanying crack formation.The durability of the lining is largely determined by the correspondence of the chemical nature of the lining material with the chemical composition of the slags. Under the influence of converter slag with a basicity of 3,1–4.5, the rate of transfer of SiO₂ from the acid lining to the slag increases by 2–3 times in comparison that observed for slag with a basicity of 2.5–3.35. This in tarn leads to more intense decrease in the basicity of the ladle slag, enhancing its fluidity and causing intense wear of the lining in the lower sector of the ladle.The results of industrial tests showed that the most agressive effect on an acid lining is exerted by fluid slags with a basicity of 2.1–2.7. Slags of lower basicity are more viscous and closer in chemical composition to that of the lining. Slags of higher basicity have a higher viscosity and their penetrative power is therefore less.Translated from Ogneupory, No. 7, pp. 28–33, July, 1979.     

Kinetic conditions for the forced transition of macromolecules of an acrylonitrile copolymer into the uncoiled state

Conclusions -- The transition of the macromolccule of an acrylonitrile copolymer into the uncoiled state in lengthwise flow of aqueous salt solutions at concentrations from 1 · 10^–3 to 5 · 10^–2 g/cm³ has been studied.-- The critical velocity gradients at which the tangled state of the macromolecules becomes unstable in a lengthwise field have been determined. It has been shown that the values of these agree well with predictions of the theory of semidilute polymer solutions.Translated from Khimicheskie Volokna, No. 2, pp. 19–21, March–April, 1993.     

Preparation of a fibre-forming sulfonic acid copolymer and its properties

Conclusions The basic principles in synthesis of a fibre-forming sulfonate group-containing copolymer have been established.It has been shown that the sulfonate group content of a copolymer shows up in its properties and the properties of its dilute solutions.Translated from Khimicheskie Volokna, No. 2, pp. 16–17, March–April, 1988.     

Morphological and structural features of polyacrylonitrile fibres spun by the dry-wet method

Conclusions -- A technological regime for the preparation of polyacrylonitrile fibres from binary and ternary copolymers has been chosen; these differ from known specimens in having a more uniform cross-sectional structure and a smoother elementary filament surface.-- A considerable difference in crystalline structure of fibres from binary and ternary copolymers which have been spun into a dimethyl sulfoxide—water bath has been shown.-- Fibres from the binary or ternary copolymer which have been spun into a precipitation bath having a large dimethyl sulfoxide content in water are characterized by a lower degree of swelling.-- Shrinkage of fibres from the binary copolymer in the temperature range 200–220°C is twice as small as the shrinkage of fibres from the ternary copolymer.Deceased.VNIIPV. Translated from Khimicheskie Volokna, No. 3, pp. 19–22, May–June, 1991.     

Structural and chemical changes in ftorlon fibre on sulfonation with gaseous sulfur trioxide

Conclusions It has been shown that, on treatment of Ftorlon fibre with gaseous sulfur trioxide, a replacement of methylene groups hydrogens in the vinylidene fluoride by sulfonic acid groups takes place; thereupon dehydrofluorination and oxidation of the copolymer take place simultaneously.The intensity of oxidation-destructive processes rises as the SO₃ concentration is increased, or as the duration and temperature of the treatment is increased.The total exchange capacity of the chemisorbents obtained is determined by the presence of sulfonic acid and carboxyl groups.Translated from Khimicheskie Volokna, No. 5, pp. 50–52, September–October, 1988.     

Mass-transfer processes in sorption of gases by VION AN-1 and VION AS-1 fibres

Conclusions Coefficients of internal diffusion and of mass-transfer have been measured in the sorption of hydrogen chloride, nitrogen dioxide, and iodine by weakly basic and strongly basic chemisorptive fibres.A large effect of moisture content and basicity of the chemisorptive fibres on mass-transfer processes in the sorption of gases has been demonstrated.Translated from Khimicheskie Volokna, No. 6, pp. 9–10, November–December, 1988.     

Investigation of the supermolecular structure parameters of fluorine-containing monofilaments

Conclusions The structure-sensitive coefficient of oriented fluorine-containing monofilaments rises with increase in the melt flow index.A dependence of crystallite defectiveness on the melt flow index has been detected for the tetrafluoroethylene-ethylene copolymer.The strength of monofilaments from a copolymer of tetrafluoroethylene with perfluoroalkyl vinyl ether is less than that of monofilaments from a tetrafluoroethylene-ethylene copolymer; this agrees with the larger values of the structure-sensitive coefficient for the first.Translated from Khimicheskie Volokna, No. 5, pp. 31–32, September–October, 1984.     

Carbochain ion-exchange fibres prepared by the graft polymerization method

Conclusions A comparative analysis has been made of the laws governing the process of graft polymerization of partially hydrolyzed PAN fibres with monomers of ionogenic and nonionogenic character.It has been shown that the activity of the investigated monomers in graft polymerization reactions and their effective conversion are reduced, as a rule, with increase in the charge of the monomer, and the homopolymer content is increased.In selecting optimum conditions for a graft polymerization as a method of preparing fibrous ion-exchangers, along with the yield of graft copolymer and the effective conversion, one should also take into account the proportion of active functional groups in the graft copolymer.Leningrad Institute of Textile and Light Industry. Translated from Khimicheskie Volokna, No. 1, pp. 19–22, January–February, 1987.     

Brightening and sizing preparation for finishing viscose textile yarn

Conclusions A brightening and sizing preparation has been developed which is based on a copolymer having a high content of acrylic ester units, prepared by a one-stage, high-temperature hydrolysis of an acrylonitrile copolymer in the presence of a mixture of water and an aliphatic alcohol.Use of this preparation (as compared with the use of polyvinyl alcohol) ensures a 15–25% reduction in breakage and amount of waste in rewinding viscose textile yarn.Translated from Khimicheskie Volokna, No. 2, pp. 27–28, March–April, 1988.     

Water-swelling behavior of an ethylene–vinyl alcohol copolymer in the presence of sorbed sodium chloride

The swelling behavior of water in a poly(ethylene–vinyl alcohol) copolymer (70 mol % vinyl alcohol) has been characterized at 25°C by vapor and liquid sorption experiments over a range of water activities. The activity of the vapor phase has been varied by incrementing the pressure of the water vapor in the sorption cell. Alternatively, for the liquid phase experiments, aqueous sodium chloride solutions of different concentrations have been used to vary systematically the activity of the water in the salt solution and to introduce various concentrations of salt into the copolymer films. Relaxation-controlled sorption and Fickian diffusion have been observed as limiting cases of the water sorption behavior at high and low water activities, respectively. The effects of sorbed sodium chloride on water vapor sorption kinetics and equilibria were determined independently. A second salt phase forms within the previously homogeneous and seemingly single phase polymeric system, upon contacting the salt-loaded film with a water vapor activity above a threshold value corresponding to the activity of water in the salt solution used to introduce the salt into the films. The water and salt solubilities in the ethylene–vinyl alcohol copolymer have been measured systematically to describe the complex sorption equilibria associated with this three-component, multiphase system.     

Viscosity properties of acrylonitrile-sodium methallylsulfonate copolymer solutions

Conclusions To obtain structurally uniform solutions of the acrylonitrile-sodium methallylsulfonate copolymer, it is advisable to prepare them at elevated temperatures.An effect of structural homogenization of concentrated solutions of the copolymer has been detected in the process of temperature treatment at 60–80°C.Translated from Khimicheskie Volokna, No. 2, pp. 27–28, March–April, 1986.     

Thermoreversible Hydrogels XVI: Synthesis and Swelling Behaviors of [N-Isopropylacrylamide–co-trimethyl acrylamidopropyl ammonium iodide-co-3-dimethyl (methacryloxyethyl) ammonium propane sulfonate] Copolymeric Hydrogels in Aqueous Salt Solution

A series of copolymeric hydrogels were prepared from various molar ratios of N-isopropylacrylamide (NIPAAm), trimethyl acrylamidopropyl ammonium iodide (TMAAI), and 3-dimethyl (methacryloxyethyl) ammonium propane sulfonate (DMAPS). The swelling behaviors of these copolymeric hydrogels were investigated in various saline solutions. The result showed that the phase transition temperatures of these gels changed insignificantly, and the thermosensitivity, in contrast, diminished. In the saline solution, results showed that the swelling ratio of pure NIPAAm gel did not significantly change with an increase in the salt concentration until the salt concentration was larger than 0.5 M. In addition, the copolymer gels exhibited polyelectrolytic behavior under lower salt concentration (10^–5–10^–1 M), exhibited a nonionic gel (like NIPAAm) behavior at the salt concentration from 0.1 to 0.5 M, and showed an antipolyelectrolytic behavior (polyzwitterionic effect) at a concentration of salt over 0.5 M.     

Effect of radiation cross-linking on the thermomechanical properties of fibres from a tetrafluoroethyleneethylene copolymer

Conclusions The effect of radiation dose on the heat-resistance of fibres from a tetrafluoroethyleneethylene copolymer has been investigated.It has been shown that, as a result of irradiation, the use temperature of the fibres can be raised by 80°C.Translated from Khimicheskie Volokna, No. 1, pp. 37–38, January–February, 1988.     

Molecular weight distribution of acrylonitrile-2-methyl-5-vinylpyridine copolymers

Conclusions A fractionation of an acrylonitrile-2-methyl-5-vinylpyridine copolymer with respect to composition and molecular weight has been carried out by the fractional precipitation method. The distribution of the copolymer with respect to composition has a bimodal character, which may exert an effect on the properties of solutions and fibres.The parameters and K in the Mark-Kuhn-Houwink equation have been determined by the sedimentation method; they are equal to 0.89 and 2.062×10^–4, respectively.Translated from Khimicheskie Volokna, No. 5, pp. 17–18, September–October, 1985.     

The preparation of fibrous anion-exchange resins based on a graft copolymer of polycaproamide-polyglycidyl methacrylate and polyethylene polyamine

Conclusions -- A mathematical model for the amination reaction of the PCA-PGMA graft copolymer has been constructed which adequately describes the process.-- The problem of optimizing the process of aminating the PCA-PGMA graft copolymer with polyethylene polyamine has been solved. The chemisorbents prepared at the optimum regime have an SEC of up to 3.7 meq/g.Translated from Khimicheskie Volokna, No. 5, pp. 34–35, September–October, 1991.