Vinylimidazole chemisorption fibre

Kalyanova, N. F.; Бараш, А. Н.; Zverev, M. P.

doi:10.1007/bf00572794

Cited by 3 publications

(2 citation statements)

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“…This is also indicated by the data on the decrease in the weight of the fibre during sorption regeneration (approximately 10% after one cycle). The results obtained suggest that the epoxy oligomer reacts with the active groups of the copolymer, forming a three-dimensional chemical network (perhaps according to the mechanism established previously for the copolymer of acrylonitrile with 5-vinyl-2-methylpyridine [4]), which ensures the stability of the fibre in media of dilute acids and hydroxides. Incorporation of a chemically active monomer --VIM --in the macromolecular polyacrylonitrile chain thus alters the inter-and intrarnolecular interaction, which affects the rheological properties of solutions of the copolymer and sph-ming, drawing, and the properties of the fibre.…”

Section: Table 2 Effect Of the Composition Of Spinning And Plasticizsupporting

confidence: 53%

Properties of solutions of the copolymer of acrylonitrile with vinylimidazole and fabrication of a fibre from it

1997

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When chemically active vinylimidazole is incorporated in the macromolecular polyacrylonitrile chain, an anomalous deviation of the viscosity from Newtonian flow is observed with an increase in the shearThe fundamental conditions for synthesis of the copolymer of acrylonitrile (AN) and vinylimidazole (VIM) for fabrication of fibres with chemisorption properties with respect to platinum-group metals, whose extraction is extremely important for the national economy, were previously established in [1].Incorporation of bulky molecules of VIM in the macromolecular polyacrylonitrile chain affects the properties of solutions of the copolymer, which in turn affects the physicomechanical indexes of the fibre [2]. We attempted to evaluate the properties of concentrated solutions of the copolymer as a function of the ratio of its components and to determine the effect of the conditions of spinning the fibre on its characteristics in use.AN--VIM copolymer with a concentration of VIM of under 40 wt. % and intrinsic viscosity [17] of 1.25-2.30 dl/g was investigated. The intrinsic viscosity of solutions of the copolymer in dimethyt sulfoxide (DMSO) was determined on a Ubbelohde viscometer. The rheological properties of the concentrated solutions were investigated on a VPN-0.1 constant shear stress viscometer. The composition of the AN-VIM copolymer was determined based on the concentration of saponified nitrogen [3]. The fibre was spun on a laboratory microbench with solution feed of 0.794 errra/min and a rate of 3.14 m/min using a spinneret with 40 openings 0.08 mm in diameter. In measuring the maximum rate of separating the fibre from the spinning bath, a spinneret with one opening 0.1 mm in diameter was used. A three-dimensional chemical network was formed in the fibre during thermal drawing using ED-20 epoxy--bisphenol A oligomer added to the spinning solution.The data on the flow of equiviscous solutions with a different concentration of chemically active monomer in the chain in reduced coordinates (Fig. 1, curves 1 and 3) were compared to determine the effect of the composition of the copolymer on the rheological properties of its solutions. The ratio of the effective r/e f tO the initial ~70 viscosity and the product of the shear rate gradient ~ and 7/0 were used as variables. For comparison, the curve of flow of a more viscous solution of the copolymer containing 33.3% VIM (curve 2) is also shown in Fig. 1. When the concentration of VIM in the copolymer is decreased to 11.5 % (curve 2), the deviation of the mode of flow of the solution from Newtonian appears for lower values of ~r/0. Index n in the following equation was used for evaluating the anomalous deviations of flow of the solutions of copolymer I~ = nlgr + lgk. where ~-is the shear stress; and k is a constant characterizing the effective viscosity of solutions of the polymer.All-Russian Scientific-Research Institute of Polymer Fibres, Mytishchi.

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Section: Table 2 Effect Of the Composition Of Spinning And Plasticizsupporting

confidence: 53%

Properties of solutions of the copolymer of acrylonitrile with vinylimidazole and fabrication of a fibre from it

1997

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“…In this case, acrylonitrile is usually usedas the fibre-forming component, and the composition of the ionogenic comonomers responsible for incorporation of sorptionactive groups in the structure of the fibre is relatively varied. This concerns methylvinylpyridine (MVP), vinylimidazole, sodium p-styrenesulfonate, and others [3,[5][6][7][8]. The fibres spun from the copolymers obtained undergo chemical or heat treatment to form a three-dimensional spatial network in them that prevents dissolution of the fibres in the sorption medium and makes it possible to use them repeatedly in sorption--desorption cycles.…”

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Chemisorption fibres based on graft copolymers: Fabrication and properties. A review

Druzhinina¹,

Nazar'ina²

1999

Fibre Chem

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Scientific concepts concerning the characteristics of graft polymerization to oriented polymeric materials and p~lymer-anal~g transf~rmati~ns ~f the graft p~lymer were elab~rated based ~n systematic studies. The principles of fabrication of sorption-active fibre materials Of different ~,pes based on graft copolymers and the most important directions of their use were formulated.The consequences of human technological activity has sharply worsened the environmental situation, making environmental protection an urgent modern problem. One direction in the complex solution of these problems is to develop highly efficient processes for scrubbing of industrial gas-air emissions and cleaning ofwastewaters. Sorption materials, used to prevent further environmental pollution and ensure rational resource management, are playing an important role in the creation of such processes.These materials include chemisorption fibres with a developed specific surface area which is more than one order of magnitude greater than the surface area of granulated sorbents. A comparison of the geometric surface area of fbres and granules gives an idea of the advantage of fibre sorbents over granulated sorbents, manifested by a higher rate of chemisorpticn and greater completeness of removal. In addition, the variety of forms of use of fibre sorbents favors the rational organization of technological processes.The analysis of the scientific and technical literature on fabrication of chemisorption fibres revealed the following methods:-spinning of fbres from blends of fibre-forming polymers with nonfibre-forming polymers containing ionogenic groups;-synthesis of fibre-forming copolymers containing functionally active groups and fabrication of fibres from them; -incorporation of functionally active groups in the fibre via reactions in the polymer chains; -modification of fibres by graft polymerization of ionogenic and nonionogenic monomers with subsequent polymeranalog transformations of the graft chains.Spinning of chemisorption fibres from polymer blends is a relatively simple method. However, the difficulties of obtaining stable spinning solutions from blends of fibre-forming and nonfibre-forming polymers and the possibility of washing out the sorption-active component of the fibre make it necessary to conduct an additional operation of formation of a threedimensional spatial network in the fibre [1,2]. Moreover, this method can be used together with other variants for production of sorption-active materials.The method of spinning fibre chemisorbents from copolymers with chemically active groups in the main chain has been widely used in fabrication of chemisorption fibres of the VION group [3,4]. In this case, acrylonitrile is usually usedas the fibre-forming component, and the composition of the ionogenic comonomers responsible for incorporation of sorptionactive groups in the structure of the fibre is relatively varied. This concerns methylvinylpyridine (MVP), vinylimidazole, sodium p-styrenesulfonate, and others [3,[5][6][7][8]. The fibres...

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Removal of heavy metal using poly (N-vinylimidazole)-grafted-carboxymethylated starch

El‐Hamshary

Fouda

Moydeen

et al. 2014

International Journal of Biological Macromolecules

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Vinylimidazole chemisorption fibre

Cited by 3 publications

References 1 publication

Properties of solutions of the copolymer of acrylonitrile with vinylimidazole and fabrication of a fibre from it

Properties of solutions of the copolymer of acrylonitrile with vinylimidazole and fabrication of a fibre from it

Chemisorption fibres based on graft copolymers: Fabrication and properties. A review

Removal of heavy metal using poly (N-vinylimidazole)-grafted-carboxymethylated starch

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