The method of obtaining chemisorptive carboxyl-containing fiber
(57) Abstract:Usage: in the chemical industry as a fibrous ion-exchange materials. The inventive polyacrylonitrile fiber with 1.5 wt.% carboxyl groups treated with an aqueous solution containing 8-15 wt. % hydrazine and 1.0-2.0 wt.% sodium hydroxide, at 90-100oC for 120-150 minutes 1 table. The invention relates to the production of ion-exchange fibers, and in particular to methods of obtaining chemisorptive carboxyl-containing fiber with a three-dimensional chemical net.A method of obtaining an ion-exchange polyacrylonitrile fiber processing freshly formed fibers with a solution of sodium hydroxide and hydrazine sulfate 
There is a method allows to simplify and reduce the cost of obtaining fiber and increase its absorption capacity, however, the fiber has a relatively low strength characteristics.A method of obtaining an ion-exchange fiber, using the processing of acrylic fiber in an aqueous solution of hydrazine hydrate is added and the sodium hydroxide solution 
There is a method allows to obtain fibers with high sorption capacity in the known way to obtain the ion-exchange polyacrylonitrile fibers by treatment of the fibers with a solution of a derivative of hydrazine and sodium hydroxide solution 
In this way the combination of processes of hydrazidine and alkaline hydrolysis in one technological stage reduces the duration of treatment, technological mode is easier than the previous method, but it requires a large consumption misusage and structuring of reagents (up to 120 g/l each). The total salt concentration of hydrazine and NaOH is about 24 wt. In addition, as a source of fiber in this case is used only svezhevorovanny not polyacrylonitrile fiber having a porous structure, which ensures penetration of hydrazine to the nitrile groups of the polyacrylonitrile, which promotes the formation of three-dimensional chemical grid. Dried (ready) polyacrylonitrile fiber such capacity does not have and therefore, when used as the initial standard Nitron fiber formation of three-dimensional grid is not happening.A method of obtaining chemisorptive carboxyl-containing fiber processing polyacrylonitrile fibers containing at least 1.5 wt. carboxyl groups, an aqueous solution of hydrazine and sodium hydroxide at a temperature of 90oC  there is a method assests hemosorption carboxyl-containing fiber processing polyacrylonitrile fibers, containing not less than 1.5 wt. carboxyl groups, in an aqueous solution of hidroinstalime compounds and sodium hydroxide at an elevated temperature within 120-150 minutes  the Known method is selected as a prototype. The known method is the one, but has a significant consumption of reagents.The present invention is the creation of a more efficient way to obtain chemisorptive polyacrylonitrile fiber-based copolymer containing in its structure at least 1.5 wt. monomer with carboxyl groups (based on acrylic fibre) with the required mechanical and sorption properties, reducing the consumption of reagents.The technical result of the present invention is to simplify and cheapen the process of obtaining chemisorption of acrylic fiber with high strength characteristics.This will allow the process of obtaining a chemisorptive fiber not only at the enterprises producing acrylic fiber, but also on any chemical production using industrial fiber Nitron.This effect is achieved by one of the a group, aqueous solution of 8-15 wt. hydrazine and 1.0-2.0 wt. sodium hydroxide at a temperature of 90-100oC for 120-150 minutesThese processing modes polyacrylonitrile fiber (standard Nitron fiber) containing not less than 1.5 wt. monomer with carboxyl groups, ensure penetration of molecules of hydrazine to the nitrile groups of the original fiber and thereby create conditions for the formation of three-dimensional chemical grid. The presence of the three-dimensional structure, as is well known, prevents subsequently, as in the processing of fibers, and operating products, dissolution of the polymer in water and organic solvents.By changing various process parameters (concentration of hydrazine and sodium hydroxide, temperature and reaction time) of the obtained experimental data, which are presented in the table.Example 1. Polyacrylonitrile staple fiber Nitron loaded into a perforated basket reactor under irrigation softened water and mechanical seal.Basket fiber installed in the reactor, chemical processing, close the lid and fill with a heated aqueous solution containing 13 wt. hydrazine and 1.5 wt. hydrox the EO pump heat exchanger reactor. Process temperature 95oC, a duration of 150 minutesUpon completion of the reaction, the spent solution is poured into the container to strengthen and subsequent use.The fiber in the reactor was washed with softened water in circulation. One rinsing for 15-20 minutes, room temperature, number of washes, 5-7.The treated fiber is unloaded from the reactor and placed in the dryer. Drying temperature 80-90oC. the Fiber is dried to a moisture content of not more than 10 wt.Physico-mechanical and sorption properties of the obtained carboxyl-containing fibers are shown in table (sample 3).Example 2. The experience carried out as described in example 1, but instead reactor chemical processing using a centrifuge holds. The fiber is treated with a solution containing 15 wt. hydrazine and 1 wt. of sodium hydroxide. Process temperature 95oC, time of 150 minutes.Washing and drying of the fibers is carried out at the modes mentioned in example 1.Physico-mechanical and sorption properties of the obtained fiber are shown in table (sample 2).The analysis is shown in table experimental data shows that obtaining the required characteristics is provided only pot at a temperature of 90-100oC.When the concentration of hydrazine is higher than 15 wt. the fiber has a low COE (sample 1), while when the concentration of hydrazine below 8 wt. fibers with a low breaking strength (samples 4-6).Increasing the reaction temperature above 100oC leads to a significant reduction of fiber (sample 10), and the temperature drops below the 90oC lowers the rate COE (sample 9).Pretty much the same effect on the magnitude of bursting strength increase reaction time more than 150 minutes (sample 12), while reducing it below 120 minutes reduces COE (sample 11).The data show that increasing the concentration of sodium hydroxide of more than 2 wt. results in chemisorption fiber with a low breaking strength (samples 6, 7), while the decrease in concentrations less than 1.0 wt. when the concentration of hydrazine 13% reduction in COE to 3.8 mgecw/g (sample 8).From the above it is evident that the chemisorptive fiber obtained at a concentration of hydrazine 8-15 wt. the concentration of sodium hydroxide and 1.0-2.0 wt. and the reaction temperature 90-100oC for 120-150 minutes on physico-mechanical and sorption parameters satisfy the requirements is about, the increase in strength properties of the obtained fiber has a positive effect on the strength characteristics when producing non-woven materials, resulting in reduced waste during production and also has a positive effect on economic performance. The method of obtaining chemisorptive carboxyl-containing fiber processing polyacrylonitrile fibers containing at least 1.5 wt. carboxyl groups, in an aqueous solution of hidroinstalime compounds and sodium hydroxide at an elevated temperature for 120 to 150 min, wherein the treatment is carried out with an aqueous solution containing 8 to 15 wt. hydrazine and 1.0 to 2.0 wt. sodium hydroxide at 90 100oC.
FIELD: sanitary and hygienic facilities.
SUBSTANCE: invention relates to technology of manufacturing chemisorption materials for use in municipal hygiene sphere. Method consists in treatment of chemisorption carboxyl-containing material in Na form with 0.5-1.0% aqueous acid solution, e.g. hydrochloric acid solution, at modulus (ratio of weight of chemisorption material to acid solution volume) 1:30 and treatment time 0.5-1.0 h to transfer material into H-form. Chemisorbent is then washed with softened water to pH 5-6, after which material in H-form is treated for 0.5-1.0 h with 0.5-1.0% potassium hydroxide solution, modulus 1:30. At the expiration of treatment time, material is washed with softened water to pH 5.0-6.5. Presence of three-dimensional lattice, both during treatment time of chemisorption material in the form of fibers or nonwoven material and upon use of products from this material, prevents dissolution of polymer in water or in aqueous solution of acid or potassium hydroxide. Owing to filtration, chemisorbent entraps in water heavy metal ions contained therein and water is saturated with potassium ions so that chemisorption material acquires at least 4 mmol/g of carboxyl groups in K-form.
EFFECT: optimized manufacture conditions.
SUBSTANCE: invention relates to technology for preparing sorbents with fibrous structure by using waste of industrial manufacture. Method involves treatment of fibrous matrix from waste of tanning leather chips with polyelectolyte an aqueous solution obtained by alkaline hydrolysis of polyacrylonitrile or copolymer based on thereof. Prepared sorbent shows the improved capacity for extraction of different components from different aqueous media.
EFFECT: improved preparing method, improved and valuable properties of sorbent.
2 cl, 1 tbl, 2 ex
FIELD: polymer materials.
SUBSTANCE: invention relates to manufacture of ion-exchange fibers with special properties, which can be used as sorbent or as a sorbent constituent for cleaning liquid media, largely natural and waste waters. Method consists in performing alkali hydrolysis of polyacrylonitrile fiber in presence of hydrazine at elevated temperature completed by treatment of fiber with active agent causing degradation of chromophore groups of fiber. Alternatively, ion-exchange fiber is manufactured via alkali hydrolysis of polyacrylonitrile fiber in presence of hydrazine at elevated temperature, hydrolysis reaction being effected in concentrated solution of salt of alkali metal with weak acid followed by treatment of fiber with active agent as above.
EFFECT: improved characteristics of fiber at lower consumption of reagents and stabilized manufacturing process to provide ion-exchange fiber with desired number of chelating sorption groups due to appropriate balance of acid and basic groups resulting from hydrolysis.
18 cl, 5 tbl, 16 ex
FIELD: waste water and gas emission treatment.
SUBSTANCE: invention relates to methods for preparing catalytic materials to clean waste waters and gas emissions via removal of organic and inorganic components by liquid-phase oxidation process. Method comprises consecutive treatment of knitted cloth with hot alkali solution containing 14-42 g/L hydroxylamine chloride and an aqueous solution of variable-valence metal salts. In the first stage, treatment is carried out with modifying hydroxylamine chloride and ethylenediamine-containing solution wherein molar ratio of polyacrylonitrile unit number to ethylenediamine ranges from 2 to 10 and solution pH is 6-9. Treatment temperature is 95-105°C and treatment time 1-1.6 h. In the second stage, treatment with aqueous solution of variable-valence metal salts is carried out for 0.5 to 2 h.
EFFECT: simplified manufacture technology, reduced expenses on reagents, and reduced process time without loss in the firmness of fixation of variable-valence metal salts on cloth.
2 tbl, 21 ex
FIELD: catalysts for waste water and emission gas treatment.
SUBSTANCE: invention relates to technology of removing organic and inorganic components from waste waters and emission gases via liquid-phase oxidation, in particular, to preparing textile-supported polymer catalyst consisting of polyacrylonitrile monothreads and complex threads. Knitted cloth is treated with modifying solution at 106 to 150°C for 10 to 30 min when ratio of amounts of polyacrylonitrile units to amount of chlorine-containing hydrazine salt equal to 20-30 and the same to chlorine-containing hydroxylamine salt 10-15, pH of solution being 6-9. After that, cloth is treated with transition metal salts for 1.0-2.0 h until content of metal on catalyst achieves 0.81-1.2 mmol/g. Treatment is followed by washing with desalted water.
EFFECT: simplified catalyst preparation technology and intensified preparation process.
2 cl, 2 tbl, 30 ex
FIELD: chemical technology, resins.
SUBSTANCE: invention relates to a method for preparing polyhalide strong-basic anion-exchange resins of gel and macroporous structure designated for disinfection of water in closed ecological objects, domestic drinking water and water from non-checked sources. Polyhalide anion-exchange resins is prepared from strong-basic quaternary ammonium anion-exchange resins in chloride form by their iodination with J2 solution in KJ at stirring, thermostatic control and washing out. Iodination is carried out with triiodide solution on conditioned strong-basic anion-exchange resins in chloride form in the content of strong-basic groups 80%, not less, in the mole ratio anion-exchange resin : triiodide = 1.0:(1.1-1.5). Ready product is kept at 20-55°C additionally. Invention provides preparing polyhalide anion-exchange resins characterizing by high resource in water disinfection and in simultaneous reducing iodine release in disinfecting water in retention of high disinfecting indices.
EFFECT: improved preparing method.
1 tbl, 8 ex
FIELD: ION-EXCHANGE MATERIALS.
SUBSTANCE: invention relates to a process of preparing gel-like cationites for use in treatment and purification processes. Gel-like cationites are prepared by inoculating-incoming process wherein (a) aqueous suspension of microcapsulated cross-linked styrene polymer in the form of granules and containing cross-linking agent is provided as inoculating polymer; (b) inoculating polymer is left to swell in monomer mixture composed of vinyl monomer, cross-linking agent, and radical initiator, namely peracid aliphatic ester; (c) monomer mixture is polymerized in inoculating polymer; and (d)resulting copolymer is functionalized via sulfatization. Process is characterized by that, in step (a), content of cross-linking agent in cross-linked styrene copolymer amounts to 3.5-7 wt % and inoculum-to-income ratio in step (b) amounts to 1:(0.25-1.5).
EFFECT: enabled preparation of gel-like cationites having high osmotic and mechanic stabilities as well as improved oxidation resistance.
7 cl, 9 tbl, 9 ex
FIELD: chemical technology.
SUBSTANCE: invention relates to technology for preparing chemosorption materials possessing high protective properties with respect to ammonia vapors that can be used for using in filtering protective devices. Method involves impregnation of nonwoven activated fabric made of hydrocellulose fibers in an aqueous solution containing zinc chloride and nickel chloride. Also, this solution contains 1,2,3-propanetriol (glycerol) as a modifying agent taken in the amount 0.5-1.0% of the total amount of the prepared solution.
EFFECT: improved preparing method.
1 tbl, 1 ex
SUBSTANCE: invention can be used for extracting metal ions, purifying waste and industrial solutions from toxic metal ions. The method of obtaining anion-exchange fibre material involves reacting activated polyacrylonitrile fibre nitron and 30-70 wt % modifying agent - mixture of diethanolamine with 10-30 wt % hexamethylenediamine in an aqueous 5% solution of dimethylformamide. Nitron is activated in a 3-6% aqueous alkaline solution for 3-5 minutes at 90-95°C.
EFFECT: invention makes it easier to obtain fibrous anionite and can be used for effective purification waste water from leather industry and electroplating plants from chromium (VI) ions, and for concentrating and separating chromates from industrial solutions.
1 tbl, 4 ex
SUBSTANCE: composition is meant for producing cation-exchange fibre material used in water treatment processes and treatment of industrial sewage. The composition is also used to soften and desalinate water, in production of synthetic detergents, in the paint industry and industry of polymer materials. The composition consists of paraphenol sulphonic acid and formalin. The composition additionally contains filler - basalt wool. The basalt wool is first heat treated for 1 hour at temperature 350-450°C, followed by microwave treatment at 180 or 750 W for 30 s. Content of components is as follows, wt %: paraphenol sulphonic acid 50-55.8, formalin 40.9-35.1; basalt wool 9.1. The composition enables synthesis of cation-exchange fibre material with improved properties, particularly lower oxidation number of the filtrate, higher specific volume of the cationite, as well as high dynamic exchange capacity and high osmotic stability of the cationite.
EFFECT: composition enables synthesis of cation-exchange fibre material with improved properties.
1 tbl, 4 ex