Spinning hydrocellulose fibres into zinc-free precipitation baths

Conclusions -- It has been found that the introduction of sodium vinyl sulfonate into the solvent alkali does not exert any important effect on the properties of the viscose, with the exception of stabilizing the cellulose xanthate and retarding its coagulation under the conditions of viscose ripening.-- Sodium vinyl sulfonate added to the dissolving alkali reacts with groups in the cellulose xanthate and to a very slight degree with hydroxyl groups in the cellulose.-- Fibres have been spun from the viscose containing sodium vinyl sulfonate, in the preparation of which it was possible to carry out a higher orientation stretch and to attain better physico-mechanical indices as compared with fibres from viscose containing no sodium vinyl sulfonate.Translated from Khimicheskie Volokna, No. 1, pp. 38–40, January–February, 1991.     

Spinning of hollow and matrix fibres from polysulfone melt

The possibility of fabrication was demonstrated and the basic technological parameters for spinning polysulfone fibres by the high-production melt method were determined. The polysulfone fibres developed were used as matrix and hybrid structures; thermostable composites with elevated physicomechanical properties were fabricated from such semifinished products.V. V. Gorlov participated in fabrication of the hollow fibres.Translated from Khimicheskie Volokna, No. 6, pp. 29–31, November–December, 1994.     

Preparation of polyacrylonitrile fibre by spinning into organic baths

Conclusions -- The spinning of polyacrylonitrile copolymers into organic baths containing dimethyl sulfoxide and isopropyl alcohol has been investigated. It has been found that the optimum DMSO:IPA ratio in the precipitation bath is 60:40% by wt..-- It has been discovered that the strength of the spun yarn is higher the lower the jet stretch.-- The effect of temperature on orientation stretch ratio has been studied. It has been shown that the optimum temperature for heat stretching of PAN yarn lies in the range 155–160°C.-- The dimethyl sulfoxide content of yarn has been determined by technological transitions. In the final yarn it does not exceed 0.3–1.2% by wt.VNIIPV. Translated from Khimicheskie Volokna, No. 3, pp. 15–16, May–June, 1991.     

Special features in spinning cuprammonium fibres into aqueous-organic baths

Conclusions A number of aqueous—organic baths which are usable in spinning cuprammonium fibres have been studied.It has been shown that the composition, precipitating power of the precipitation bath, and spinning conditions predetermine the physicomechanical properties of cuprammonium fibres.Translated from Khimicheskie Volokna, No. 5, pp. 18–20, September–October, 1984.     

Fabrication of carbon fibres from wet-spun commercial polyacrylonitrile fibres

The possibility of fabricating carbon fibre from commercial PAN fibres for textile applications was demonstrated. It is necessary to make some changes in the temperature—time conditions for total completion of the thermal stabilization process. Better strength of the carbon fibres, equal to 1401 MPa, was attained in conducting thermal stabilization cycle B. __________ Translated from Khimicheskie Volokna, No. 5, pp. 31–33, September–October, 2006.     

Some features of spinning cuprammonium fibres into precipitation baths containing calcium salts

Conclusions On the basis of data on precipitating power and the rate of dehydration of cuprammonium solutions of cellulose, the fundamental possibility has been demonstrated of spinning fibres from such solutions into precipitation baths containing calcium salts, using the technological scheme for viscose fibre manufacture.The dependence of the basic characteristics of the freshly-spun fibre on calcium salt content and temperature of the precipitation bath has been found.Moscow Textile Institute. Translated from Khimicheskie Volokna, No. 1, pp. 11–13, January–February, 1987.     

Preparation of crimped polyacrylonitrile fibres

Conclusions The effect of the concentration of the components of the modifying solution and of its temperature on the degree of crimp of polyacrylonitrile fibre has been described.It has been found that the modifying solutions are rather stable in storage for several days at 4–5°C; at room temperature a decomposition of a complex compound formed by the organic components apparently takes place.Translated from Khimicheskie Volokna, No. 2, pp. 39–40, March–April, 1984.     

Spinning of poly-p-phenylenebenzobisthiazole fibres

The effect of the intrinsic viscosity and concentration of polymer in LC solution on the mechanical properties of PPBT yarn was demonstrated. In examining the spinning stability of PPBT yarns, use of spinnerets with an opening diameter of 0.25 mm and conditions ensuring cooling of the jets of heated LC solutions in an air gap are preferred. The isometric conditions of drawing of jets of a LC solution of PPBT with a ratio greater than 7–8 initiate one-dimensional flow with stable pulsation of the diameter. The phenomenon is known as draw resonance. All-Russian Scientific-Research Institute of Polymer Fibres, Mytishchi. Translated fromKhimicheskie Volokna, No. 1, pp. 23–28, January–February, 2000.     

Modification of polyacrylonitrile fibres to improve the properties of carbon fibres prepared from them

Conclusions -- It has been found that treatment of acrylonitrile fibres obtained by the wet dimethyl formamide method before thermal oxidation with inorganic salts considerably changes the properties of the thermally oxidized fibres.-- On treatment of the fibres with an aqueous solution containing copper ion in a reducing medium, their sorptive powers are considerably impaired, the fibre diameter is increased, and the electrical conductivity is increased, plus processes of cyclization and oxidation are accelerated.-- On treatment with a solution of aluminum chloride in the presence of orthophosphoric acid, the fibre structure is made denser and its strength is increased.-- Sodium thiosulfate as a modifier considerably changes the functional composition of polyacrylonitrile fibres; thereupon, a process of structural amorphization takes place.Translated from Khimicheskie Volokna, No. 5, pp. 48–50, September–October, 1991.     

Intensification of thermooxidation of polyacrylonitrile fibres

It was found that in thermooxidation of PAN fibres in air by the conductive (contact) method, the density of 1.38–1.40 g/cm³, required for subsequent high-temperature treatment, is attained in 30–60 min. The chemical composition and equilibrium sorption of the PAN fibre oxidized by convective tempering do not differ significantly from the fibre fabricated in industrial conditions in convective tempering. All-Russian Scientific-Research Institute of Polymer Fibres, Mytishchi. Translated fromKhimicheskie Volokna. No. 6, pp. 22–24, November–December, 1999.     

Effect of stretching conditions on the properties of cuprammonium fibres spun into aqueous-organic baths

Conclusions The effects of jet stretch, stretching in air, and stretching in a plasticizing bath medium on the physicomechanical properties of cuprammonium fibres spun into aqueous-organic systems have been investigated.The roles of jet stretch and orientation stretch have been demonstrated, and conditions for carrying out these operations have been refined.Translated from Khimicheskie Volokna, No. 5, pp. 20–22, September–October, 1984.     

Some properties of modified polyacrylonitrile fibres

Fibre-forming copolymers of acrylonitrile and a monomeric quaternary ammonium salt, β-methacryloylhydroxyethyl-(N-dimethyl,methylene)ammonium iodide, were obtained by wet spinning and their physicomechanical and structural properties were investigated. It was found that the modified fibres have a set of valuable properties in comparison to the industrial fibre Nitron.     

Deformation properties of modified polyacrylonitrile fibres

Conclusions Deformation properties of polyacrylonitrile fibres modified with alkali metal salts have been studied.The introduction of alkali metals by treatment of freshly spun gel-fibre with solutions of the appropriate salts aids in loosening fibre structure.Both the form of cation and also of the anion in the salt introduced affect the deformability of the modified fibres.Translated from Khimicheskie Volokna, No. 4, pp. 40–41, July–August, 1989.     

Microscopic study of modified polyacrylonitrile fibres

Conclusions Microscopic studies have been made on polyacrylonitrile fibres which have been modified with solutions of CdSO₄, ethylenediamine, and a mixture of these solutions.Treatment with an ethylenediamine solution aids in a significant change in structure of the fibre surface.Treatment with a mixture of CdSO₄ and ethylenediamine solutions leads to development of a structural nonuniformity in the fibre and the twisting of the fibre on drying in the free state.Translated from Khimicheskie Volokna, No. 2, pp. 33–34, March–April, 1989.