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.     

Manufacture of graft copolymers of polyvinyl alcohol fibres with vinyl polymers

Conclusions 1. Methods have been developed, and the conditions studied, for obtaining graft copolymers of PVA fibres with polyacrylic acid, poly-2-methyl-5-vinylpyridine and polyacrylonitrile, using for formation of macroradicals carboxyl, aldehyde, and titanium groups, introduced into the fibres when they are rendered hydrophobic.2. Certain properties of the graft copolymers thus obtained have been studied. It is shown that fibres with ionogenic graft copolymers have high exchange capacities, reaching 5.8 meq/g when poly-2-methyl-5-vinylpyridine is used.S. M. Kirov Leningrad Institute of Textile and Light Industries (LITLP). Translated from Khimicheskie Volokna, No. 5, pp. 14–16, September–October, 1969.     

Effect of the nature of the solvent on the properties of solutions of vinylidene fluoride-tetrafluoroethylene copolymer and of fibres made from it

Conclusions The effect of the nature of the solvent on the properties of concentrated solutions of the vinylidene fluoride-tetrafluoroethylene copolymer (5% tetrafluoroethylene) has been shown.It has been found that the lower physicomechanical properties of fibres spun from solvents of the amide type is caused by their larger microporosity.Translated from Khimicheskie Volokna, No. 6, pp. 17–18, November–December 1983.     

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.     

Preparation of fibres from graft copolymers of acrylonitrile and polyvinyl alcohol

Conclusions The possibility of spinning fibres from graft copolymers of polyvinyl alcohol and acryonitrile by the scheme for spinning polyacrylonitrile fibre has been established.It has been shown that spinning solutions can be prepared directly from latexes of the graft copolymers.The suggestion has been made that long side chains in the copolymers participate in formation of supermolecular structural elements and aid in obtaining fibres with adequately high mechanical strength and an increased thermal stability.Translated from Khimicheskie Volokna, No. 1, pp. 13–15, January–February, 1988.     

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 chemical fibres with fluorine-containing copolymers (review)

Modification of chemical fibres with copolymers of 1,1-dihydroperfluoro-heptyl acrylate (PFHA) to decrease their wettability was systematically investigated and some characteristics of this process were established. It was shown that the effectiveness of modification is determined by the method of treating the fibres with the copolymer modifiers, the molecular composition of these copolymers, and the colloid chemical properties of the latexes based on them. Treatment of the fibres with copolymers with functionally active groups capable of reacting with the macromolecule of the fibre-forming polymer and cross-linking on the surface of the fibre is the most effective method of modification. Substitution of incomplete fluorinated alcohols or unfluorinated monomers for the acrylates in the PFHA copolymer reduces their effectiveness in modification. Copolymers of PFHA with hydrophilic monomers capable of being orientedly sorbed by the fibre due to its amphiphilic nature and forming surfaces with low energy are an exception. For effective use of the copolymer modifier, the latexes of these copolymers should have certain colloid chemical properties: the particle charge, adsorption saturation, and aggregate stability should be optimum, which will ensure their stability during preparation, storage, and use.Translated from Khimicheskie Volokna, No. 5, pp. 27–30, September–October, 1995.     

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.     

Swelling and rheology of saponified starch–g–polyacrylonitrile copolymers. Effect of starch granule pretreatment and grafted chain length

A series of well-characterized starch–g–polyacrylonitrile (PAN) graft copolymers was prepared from corn starch which had been heated in water at temperatures up to 94°C to vary the extent of starch granule swelling and disruption. Graft polymerization onto gelatinized starch gave less frequent grafting of higher molecular weight PAN than comparable graft polymerizations onto ungelatinized starch. A graft copolymer was also prepared from gelatinized starch under high dilution conditions to give lower molecular weight grafted PAN and more frequent grafting. Graft copolymers were then saponified with sodium hydroxide to convert nitrile substituents to a mixture of carboxamide and sodium carboxylate. Saponified graft copolymers were only partially water soluble and consisted largely of highly swollen, insoluble gel, which was separated from solubles for the study of physical properties. Saponification mixtures were also dried to yield highly absorbent polymer films. With the exception of the graft copolymer prepared under high dilution conditions, the physical properties of saponified graft copolymers depended on whether or not the granules of starch were gelatinized before graft polymerization. Compared with saponified graft copolymers derived from ungelatinized starch, those prepared from gelatinized starch gave films that absorbed larger amounts of aqueous fluids. Also, the gel fractions from these saponified gelatinized polymers exhibited higher water swelling, lower shear modulus, and a lower reduced viscosity function (η/cQ). The saponified graft copolymer prepared from gelatinized starch under high dilution conditions more closely resembled those prepared from ungelatinized starch, suggesting that molecular weight of grafted PAN and the grafting frequency rather than starch granule pretreatment might be the most important factor which influences properties.     

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.     

Experimental study of the structure of polyacrylonitrile gel fibres

The structure of PAN gel fibres spun by the water-thiocyanate method is investigated. It is shown that in identical spinning conditions, the packing density of the structural elements in gel fibres based on poly(AN-co-MA-co-ItA)terpolymer is lower than in gel fibres based on poly(AN-co-MA-co-AMPS). A structural model of PAN gel fibre is composed and substantiated. It is shown that the lower packaging density of the structural elements in PAN gel fibres is responsible for the higher sorption power with respect to different inorganic and organic compounds and higher rate polymer-analog transformations.Translated from Khimicheskie Volokna, No. 5, pp. 40–45, September–October, 2004.     

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.     

Study of the Acid-Base Properties of Graft Copolymer Chemisorption Fibres by Potentiometric Titration

The content of functional groups responsible for the sorption activity of chemisorption fibres made from graft copolymers was determined by potentiometric titration and the apparent dissociation constants were calculated. It was shown that of the weakly basic ion-exchangers containing primary and secondary amino groups, the chemisorption fibre fabricated by amination of polycaproamide—polyglycidyl methacrylate copolymer grafted with ethylenediamine has the strongest base properties.     

Properties of fibres of cellulose acetomethacrylates

Conclusions 1. The authors have shown that fibres can be formed for acetic acid syrups of mixed esters of cellulose with acetic and methacrylic acids.2. The effect of the composition of cellulose acetomethacrylate on the physicomechanical properties and degree of orientation of the fibres has been studied. It has been established that maximal improvement of the strength and degree of orientation of the fibres takes place at _max=7–9.3. The change in fibre structure in relation to the methacrylic acid content has been studied by electron-microscopic analysis. It is shown that the structural uniformity of cellulose acetomethacrylate fibres improves at _max=7–9; a further increase in _max leads to a decrease of the structural uniformity.First communication of a series devoted to Preparation of fibres on the basis of cellulose esters, and study of their properties.NIIKhTTs. Translated from Khimicheskie Volokna, No. 5, pp. 41–43, September–October, 1969.     

Properties of yarns spun from a cellulose triacetate melt

Conclusions The physicochemical and physicomechanical properties of yarns spun from a cellulose triacetate melt have been studied.It has been shown that in physicomechanical properties CTA yarns spun from the melt are identical to yarns spun by the dry method.It has been found that the lower sorptive power and lower shrinkage of yarns from the melt are connected with the special features of their spinning.Translated from Khimicheskie Volokna, No. 5, pp. 23–25, September–October, 1984.     

Synthesis of a sulfonate copolymer and fabrication of a fibre from it

The conditions of synthesis of a copolymer based on acrylonitrile and sodiump-styrenesulfonate in aqueous medium were investigated and the conditions, for preparing it in dimethyl sulfoxide were developed. Fibres of AN-pSS copolymers with SEC of up to 1.4 meq/g and satisfactory physicomechanical characteristics for processing into textile articles were obtained. The direction of research to obtain chemisorption fibres with sulfonate groups is briefly examined.All-Russian Scientific-Research, Institute of Polymer Fibres, Mytishchi Translated from Khimicheskie Volokna, No. 5, pp. 52–57, September–October, 1996.     

A study of the graft polymerization of polymethacrylic acid onto polycaproamide and the preparation of modified fibres with ion-exchange properties

Conclusions Some features of the synthesis of graft copolymers of polycaproamide with polymethacrylic acid have been studied, using starting fibres with various degrees of stretch.It has been found that the graft polymerization reaction initiated by the redox system K₂S₂O₈ - Na₂S₂O₃, takes place with high efficiency under definite conditions in the presence of copper ions.The modified fibres have ion-exchange properties (SEC up to 3.8 meq/g) and satisfactory physico-mechanical characteristics for ion-exchange materials.Translated from Khimicheskie Volokna, No. 2, pp. 24–26, March–April, 1986.     

Thermal properties of polyacrylonitrile copolymers having various chemical compositions

Conclusions 1. The thermal oxidative degradation of PAN fibres having an IA content from 1.2 to 6.4% in the copolymer has been studied by the DTA method.2. Increasing the IA content of the copolymer leads to a shift of the exothermic effects of the cyclization reaction into the lower temperature region, and also to a decrease in the thermally effect from thermal oxidation, which affords a possibility of increasing the efficiency of processes of heat treatment of PAN in the preparation of carbon fibres and of reducing heat expenditures.NITs Uglekhimvolokno (Mytishchi). Translated from Khimicheskie Volokna, No. 5, pp. 25–27, September–October, 1993.     

Preparation and properties of fibres based on graft polyamide copolymers

Conclusions 1. Of the proposed methods of synthesizing graft polyamide copolymers, the use of peroxidized polycaproamide, activated by a metal of variable valence, and also radiation initiation of the graft polymerization reaction have found practical application.2. New fibres with improved hygienic, consumer, and special properties have been prepared, based on GPC.3. Effective methods of synthesizing GPC, in combination with the availability of technological equipment, have stimulated further development of the chemistry and technology of fibres from graft polyamide copolymers, which is interesting in the practical respect.Deceased.Translated from Khimicheskie Volokna, No. 4, pp. 9–14, July–August, 1984.     

Viscoelastic properties and structure of technical polyacrylonitrile tows

Conclusions The connection between supermolecular structure of PAN tows and the parameters of the creep process has been discovered, which makes it possible to carry out structural interpretation of viscoelastic properties and can be used in the analysis of technological processes for the preparation of PAN tows.It has been found that carbon fibres with a high knot strength are obtained from technical PAN tows which are characterized by a more homogeneous and oriented structure, and fibres with a low knot strength are obtained from PAN tows with a heterophase structure and less orientation.Leningrad Institute of the Textile and Light Industries. Translated from Khimicheskie Volokna, No. 2, pp. 34–37, March–April, 1992.