A method of obtaining a weakly acidic cation exchanger based on polyacrylonitrile fiber
(57) Abstract:Use: nuclear power for the control and treatment of water coolant of the primary and secondary circuits of nuclear power plants. The inventive polyacrylonitrile fiber is treated with a mixture of ethylsilicate sodium and hydrazine. Then subjected to additional irradiation with ionizing radiation with a dose of 4104-7105in an aqueous solution of hydrazine with a concentration of 0.1 - 0.5 g/l 2 Il., table 4. The invention relates to the field of chemical technology of fibrous ion-exchange materials and can be used in nuclear power to control and clean water coolant of the primary and secondary circuits of nuclear power plants.A method of obtaining an ion-exchange fibers based on polyacrylonitrile fibers (PAN-fibers) methods polymeranalogous transformations, for example by saponification (processing) sodium hydroxide 
This method is quite labor intensive, time consuming and the value of the static exchange capacity (SOY), the main characteristics of the resin, small.It is known that radiation exposure can lead to the evident stability of ion-exchange materials can be concluded, when the irradiation of the majority of the ion is reduced exchange capacity and the deterioration of their performance properties.Closest to the invention is a method for ion-exchange polyacrylonitrile fiber, conclude himself in the saponification source suzeormanshow fiber processing in aqueous solution with a mixture of ethylsilicate sodium (GGC-10) with hydrazine hydrate in a ratio of components(4:1)-(19:1) within 20-40 minutes at a temperature of 96-98aboutWith, washing and drying. This method allows to reduce processing time and increase the static exchange capacity of the ion exchanger 
The disadvantage of this method is that the surface of the fibrous materials is a strong heterogeneity, therefore, the ion-exchange groups formed on the surface of polyacrylonitrile fibers by hydrolysis of the ester and nitrile groups, have a more distorted structure than ion-exchange groups of the matrix resin (type RL-2, AV-17 and others) the Use of hydrazine with a strong reducing properties, contributes to the structuring of ion-exchange fibers, but the resulting material has a lower selectivity than the matrix ion.The technology is from polyacrylonitrile fibers. This technical problem is solved due to the fact that acrylic fiber, after processing them in a mixture of ethylsilicate sodium (NGL-10) and hydrazine, are subjected to additional irradiation with ionizing radiation to the absorbed dose 4104-7105G in an aqueous solution of hydrazine with a concentration of 0.1-0.5 g/L.Under the action of ionizing radiation in water and aqueous solutions formed by the radiolysis products of water chemically highly active particles: N-radicals and solvated electrons, which is a very strong reducing agents. Oh-radicals and hydrogen peroxide having oxidizing properties. Fibrous materials have sellersville surface, so radiolysis products, when exposed fibers in water with high efficiency can interact with the surface of the ion exchanger, producing a variety of chemical transformations.The restorative properties of H-radicals and solvated electrons is significantly superior to the properties of hydrazine-hydrate, so the irradiation PAN-fibrous ion exchanger in the water leads to additional structuring of the fibers and, consequently, to increase the selectivity of the resin.When irradiated in aqueous solution added acceptor QA is e, to interact with rehabilitation particles of the products of radiolysis of water and, therefore, reduce the effectiveness of radiation exposure.The invention consists in the following.The original freshly formed saponified POLYACRYLONITRILE fiber is treated with a mixture of ethylsilicate sodium (NGL-10) and hydrazine at a ratio of components(4: 1)-(19: 1). The treatment is carried out within 20-40 minutes at a temperature of 96-98aboutC. Upon completion of the reaction, the fiber is rinsed from impurities. Fiber is subjected to the radiation ionizing radiation to the absorbed dose (4104)-(7105) Gr. Irradiation is carried out in a solution of hydrazine with a concentration of 0.1-0.5 g/L.The invention is illustrated by the following examples.Experimentally under laboratory conditions was studied the influence of radiation on the PAN fibres treated with a mixture of ethylsilicate sodium (NGL-10) and hydrazine. The experiment was performed by the method in accordance with , followed by the radiation of the obtained resin.P R I m e R 1. Freshly formed not stretched fiber (PAN) is treated with 4% NaOH solution for 4 min at a temperature of 98-100aboutWith and dried on who is igrata in the ratio of 90:10. The resulting fiber has the following properties:
SOY 4,5 mg EQ/g (mmol/g)
Fiber strength 26,03 HS/Tex
Selective viviremos copper 3.25 mgex/g (mmol/g)
Further samples of PAN fibers, washed and dried, the weight of 2.0 g placed in glass vials with a volume of 100 ml and irradiated at the facility RKHM - -20 gamma-quanta60With, a capacity of 2.4 G/C. the Selectivity of the ion exchanger is determined by the following method. Washed and dried after irradiation the samples placed in plastic cups with 50 ml of solution. Selectivity was calculated from the ratio of the amount adsorbed and the remaining solution of the substance after a long (over 100 hours) of contact of the resin and solution 
For research were selected solutions of radioactive isotope137Cs with specific activity 1,27106Bq/l High sensitivity radiometric measurement methods allowed us to work with solutions of low concentration, which is especially important in determining the selectivity of the resin.In table. 1 shows the results of experiments.As can be seen from the presented results, exposure to ionizing radiation increases the selectivity of the resin is more than 5 times. , the effects of radiation due to the interaction of the resin with the products of water radiolysis.P R I m m e R 2. Freshly formed stretched POLYACRYLONITRILE fiber treated according to example 1 10% solution of ethylsilicate sodium and 12% solution of hydrazine hydrate in a ratio of 90:10 for 25 minutes, the Obtained fiber has the following properties:
Total capacity 5.5 mgecw/g (mmol/g)
Fiber strength 20,03 HS/Tex
Elongation of 45.6%
Selective viviremos copper 3,9 mg EQ/g (mmol/g)
Then the samples PAN-fibers, washed and dried, the weight of 2.0 g placed in glass vials with a volume of 100 ml and irradiated at the facility RKHM - -20 gamma-quanta60With, a capacity of 2.4 G/S. Forth in example 1.In table. 2 shows the experimental results obtained according to the description of example 2.Comparing examples 1 and 2 it can be noted that changes in the concentration of the modifying agent has no significant effect on the coefficient of the selectivity of the ion exchanger that obtained by the subsequent radioactive irradiation. The selectivity coefficient is still high for the water environment, as in example 1. The impact of radiation is determined largely by the composition of the aqueous phase that horosheve selectivity of the ion exchanger, and in the highly alkaline environment, the impact is reduced and exposure to acid, even passivates the ion exchanger.Thus, the positive effect of ionizing radiation is achieved only under certain conditions of exposure and is characterized by a specific composition of the solution and the dose of radiation.P R I m e R 3. The rationale for the composition of the medium during irradiation of the resin.On PAN-fibers, obtained as in example 1 treatment ethylsilicate sodium and hydrazine hydrate with SOY-4,5 mg EQ/g (mmol/g), was studied the influence of various substances, acceptors products of water radiolysis, the value of the selectivity of the resin upon irradiation. The results of the experiments are given in table. 3.From the analysis of experimental data shows that the introduction of a solution of potassium nitrate, which is the acceptor recovery of the particles reduces the effectiveness of ionizing radiation in 1.6 times. Of acceptors oxidative particles were found the most effective hydrazine hydrate.In Fig. 1 shows the dependence of the selectivity of the resin upon irradiation on the concentration of hydrazine in solution. It is seen that at a concentration of 0.3 g/l selectivity factor, which is riodic to decrease the selectivity of the resin after exposure.Thus, the optimum concentration of hydrazine in solution should be considered as 0.3 g/l, and the boundary conditions adopted in the invention is 0.1-0.5 g/L.P R I m e R 4. The rationale for the dose of ionizing radiation during irradiation.On PAN-fibers, obtained as in example 1, determined the dependence of the coefficient of the selectivity of the ion exchanger from the exposure dose at the facility RKHM--20. The concentration of hydrazine in solution during irradiation was 0.3 g/l (see Fig. 2). It is seen that increasing the dose of ionizing radiation to 4104Gr naturally increases the coefficient of the selectivity of the resin. Further increase in the dose of radiation does not lead to a substantial increase in the selectivity of ion-exchange material. At doses of more than 7105Gray selectivity factor decreases, which, apparently, is connected with the beginning of the destruction of the fibers.Thus, the optimum should take a dose of ionizing radiation 3,7105and the boundary values adopted in the claims -4104-7105Gr.P R I m e R 5. Comparison of the effectiveness of water treatment with the PAN-fibrous ion exchangers obtained by the known and proposed methods.Experimentalyou, obtained by a known method and the proposed method of example 1.The tests were carried out on aqueous solutions of waste nuclear energy containing isotopes60With134Cs and137Cs.The results are given in table. 4. A method of OBTAINING a weakly acidic CATION exchanger BASED ON POLYACRYLONITRILE FIBERS by saponification of the original vegetariano fiber, treatment with an aqueous solution of a mixture of ethylsilicate sodium hydrazinehydrate, washing and drying, characterized in that after drying, the fiber is additionally irradiated with ionizing radiation to the absorbed dose 4 1047 of 105Gray in an aqueous solution of hydrazine with a concentration of 0.1 - 0.5 g/L.
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