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.     

Modification of polyacrylonitrile fibres with halogen-containing polymers

Conclusions The physicomechanical and relaxation properties of fibres based on mixtures of polyacrylonitrile with halogen-containing polymers — polyvinyl chloride, chlorinated polyvinyl chloride, and Ftorlon — have been studied.It has been found that on introducing small additions of HCP, the physicomechanical properties of the fibres rise in an extreme fashion.Translated from Khimicheskie Volokna, No. 2, pp. 44–45, March–April, 1984.     

Modification of the surface of polyacrylonitrile fibres before oxidation with a dispersion of technical carbon

Conclusions -- The possibility of using dispersions of technical carbon in a medium of ethylene glycol, an aqueous solution of a binder of the Sokrat-binder type, or an alcoholic solution of polyvinyl butyral for the modification of polyacrylonitrile fibres before thermo-oxidation, which ensure obtaining a stable and uniform carbon-containing film on the fibre surface has been established.-- The use of ethylene glycol as the dispersion medium leads to retention of the strength of fibres after heat treatment at the level of the starting fibres and reduces the specific bulk electrical resistance.-- Application of aqueous solutions of the Sokrat-binder aids in preserving fibre strength during thermo-oxidation. The linear density of the fibre and its ability to be oxidized are increased, but the specific bulk electrical resistance and elongation are reduced.-- The use of alcoholic solutions of polyvinyl butyral makes it possible not only to preserve fibre strength but also to considerably increase it during the thermo-oxidation process. Thereupon, the linear density of the fibres is significantly reduced, and at a dispersion content of 10% by wt. technical carbon, one can obtain electrically-conducting oxidized fibres.Translated from Khimicheskie Volokna, No. 4, pp. 36–37, July–August, 1991.     

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.     

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.     

Composition and specific properties of carbon fibre sorbents based on polyacrylonitrile fibres

Conclusions -- Fibrous carbon adsorbents based on polyacrylonitrile have been synthesized in the form of tow and of a nonwoven material, with high-strength characteristics.-- Surface nitrogen-containing compounds have been determined and their connection with the sorptive and catalytic properties of the materials obtained have been defined.Translated from Khimicheskie Volokna, No. 5, pp. 19–22, September–October, 1990.     

Modern carbon fibres from polyacrylonitrile (PAN)-polyheteroaromatics with preferred orientation

This contribution presents the mechanical data of high performance carbon fibres currently available on the market, based on experimental studies on stabilization and pyrolysis of PAN (SAF) from Courtaulds. The effects of stabilization and carbonization temperatures on the properties as well as on the ultra- and crystalline structures of the fibres are shown in more detail.     

Thermomechanical and chemical properties of cross-linked polyacrylonitrile fibres

Conclusions 1. We have studied the thermomechanical and chemical properties of PAN fibres, cross-linked by treating with hydrazine hydrate, semicarbazide, and thiosemicarbazide.2. Cross-linked PAN fibres have increased heat resistances and thermal stabilities.3. Cross-linked PAN fibres do not dissolve in any known organic solvents and are resistant to hot mineral acids and alkalies.Third communication on: Deformation and thermomechanical properties of cross-linked polyacrylonitrile fibres.All-Union Synthetic Fibre Research Institute (VNIIV). Translated from Khimicheskie Volokna, No. 2, pp. 49–50, March–April, 1969.     

Production and properties of fibres from blends of polyacrylonitrile and cellulose acetate

Conclusions 1. The presence of CA/PAN graft copolymer increases the stability of mixtures of CA and PAN, and ternary polymerisation mixtures are more stable in solution than mechanical mixtures.2. Increasing the stability of mixtures of solutions of cellulose acetate and polyacrylonitrile improves the properties of the fibres spun from them, by enhancing their physicomechanical characteristics.All-Union Scientific Research Institute for Sugar Beet; Moscow Textile Institute. Translated from Khimicheskie Volokna, No. 2, pp. 16–18, March–April, 1969.     

The spinning of polyacrylonitrile fibres in clean room conditions for the production of carbon fibres

Carbon fibres have been prepared from PAN fibres spun under clean conditions to avoid contamination with impurity particles. This has enabled carbon fibres with significantly higher tensile strengths to be produced. Clean PAN fibres yielded carbon fibres with a strength of 2·75 GN/m² after heat-treatment to 2500°C whereas control fibres spun under normal laboratory conditions only gave a strength of 1·51 GN/m² after the same heat-treatment. The average strength of carbon fibres from the clean precursor increased with heat-treatment temperature and was constant for gauge lengths of 1–5 cm after heating to 2500°C. This was in marked contrast to the control fibres which decreased in strength after heat-treatment. The results indicate that by working in clean conditions the average separation of severe flaws operative below 2 GN/m² was about 20 cm. Examinations of fracture surfaces with the scanning electron microscope showed that failures were initiated at the surface in all cases.     

Effect of calcium salts on the thermal properties of polyacrylonitrile fibres

Conclusions -- On interaction of CaCl₂ with polyacrylonitrile fibres, strong chemical bonds are formed between the polymer macromolecules.-- The introduction of Ca(II) into the fibre helps reduce polymer deformation up to a temperature of 200°C and helps increase its thermal resistance.Translated from Khimicheskie Volokna, No. 6, pp. 51–52, November–December, 1990.     

Sorptive properties of fibres prepared from cuprimonium solutions of cellulose

Conclusions -- The sorption of water vapor by copper-containing and by final hydrocellulose fibres from the cuprimonium preparation method essentially does not depend on the concentration of the water-diethylene glycol precipitation bath or on stretching in the range up to 34%, which indicates formation of structures which are close to amorphous fibre in packing density under these conditions.-- The specific surface of both copper-containing and also of hydrocellulose fibres which have been dried by solvent replacement depends on the composition of the water-diethylene glycol bath, wherein this dependence has a bimodal character.VNIIPV, Mytishchi. Translated from Khimicheskie Volokna, No. 3, pp. 25–26, May–June, 1992.     

Structural and thermal characteristics of polyacrylonitrile fibres as raw material for production of carbon fibres

Three samples of polyacrylonitrile fibres used for production of carbon fibres were investigated by x-ray diffraction, differential scanning calorimetry, and thermogravimetry. It was found that spinning of polyacrylonitrile fibre with the thiocyanate method ensures a smaller crystallite size, while the composition of the copolymer affects the thermogravimetric parameters.