Method for production of aromatic polyimide nanofiber based material

FIELD: chemistry.

SUBSTANCE: method is described for production of a polyimide nanofiber based material including electrospinning of polyamide acid solution in the solvent in which the solution containing not more than 12 wt % of polyamide acid in aprotonic solvent is used to obtain the film by the method of electrospinning through split draw die to the support; the film is removed from the support and dissolved, in the quantity ensuring polyamide acid content in the solution of 12-20 wt %, in the mixture aptoronic solvent : benzoid solvent with benzoid solvent content being 20-70 vol.%; the solution is supplied at room temperature through electrode- draw die to electric field with voltage of 15-35 kV; the material deposited on the anode is subjected to thermal treatment at a temperature of 370-420°C for 60 min; the target product consists of aromatic polyimide nanofibers with diameter of 50-700 nm and has decomposition temperature higher than 500°C in the inert medium in mixture.

EFFECT: production of aromatic polyimide nanofiber based material using the method of electrospinning of polyamide acid at room temperature.

6 dwg, 5 ex

 



 

Same patents:

FIELD: chemistry.

SUBSTANCE: invention relates to the technology of producing synthetic fibres with high chemical resistance and water-repellent properties and low coefficient of friction. The method involves forming fibres from a molten polymer, depositing a brightening preparation, orientation drawing and heat fixing. The brightening preparation is deposited on a hot surface of freshly moulded fibres simultaneously with an aqueous suspension of polytetrafluoroethylene with concentration of 3-60 g/l. Orientation drawing is carried out with a repetition factor of 3-15.

EFFECT: high resistance of fibres to aggressive media, water-repellent properties and low coefficient of friction.

2 cl, 3 tbl, 3 ex

FIELD: chemistry.

SUBSTANCE: water composition contains in wt % 15-40 solution of interpolymeric complex, 50-80 aqueous solution of thickening agent (concentration 8 - 14%) and acidity regulator 2H HCl to pH=2 - 4. Interpolymeric complex is obtained by mixing 1% solution of polyacrylacid and 10% solution of polyvinyl alcohol with component ratio 1:1. As thickening agent, applied is polyvinyl alcohol or polyethylenoxide. Viscosity of composition constitutes from 0.5 to 0.9 Pa·s.

EFFECT: application of claimed spinning composition makes it possible to obtain fibres with diameter 200 - 400 nm with high indicators of hygroscopicity and steam-permeabilityat quite fast rate.

1 tbl, 3 ex

FIELD: chemistry.

SUBSTANCE: method of production involves synthesis of a copolyamide by low-temperature copolycondensation of a mixture of 5(6)-amino-2(4-aminophenyl)benzimidazole, para-phenylenediamine and terephthaloyl chloride in an amide solvent solution with addition of 2.5-4.5 wt % LiCl or CaCl2, moulding the obtained polycondensation solution, washing, drying, heat-treating and hot-stretching the obtained fibre. In one version, synthesis is carried out with addition into the reaction mass of a viscosity stabiliser in amount of 4-25 mol % of the mixture of diamines and excess terephthaloyl chloride in amount of 0.15-1.2 mol % of the mixture of diamines. In another version, the viscosity stabiliser is added in amount of 4-7.5 mol % of the mixture of diamines, and at the end of synthesis, terephthalic acid is added in amount of 0.15-1.2 mol % of the mixture of diamines and stirred until complete dissolution, and copolymer terminal groups are converted during heat treatment in an inert medium at temperature of 340-360°C. The result is obtaining an aramid fibre which is characterised by ultimate strength of 260 gf/tex or higher, initial modulus of elasticity of 16000 kgf/mm2 or higher, wherein the increase factor of strength of the fibre in microplastic is 1.6 or higher, and breaking stress is 620 kgf/mm2 or higher.

EFFECT: high ultimate strength and elasticity of the fibre.

10 cl, 1 tbl, 11 ex

FIELD: textile, paper.

SUBSTANCE: material is produced by method of polymer melt blowing. Layers are made of propylene copolymer with crystallinity that makes less than 50%. Layers have maximum value of stretching force (Fmd) in longitudinal direction per 1 inch of width normalised by density of 20g/m2, characterised with the following equations: a) Fmd ≥ [-0,00143×relative extension (%)+ 0.823], if relative extension is between 20 and 675%; b) Fmd≥0.1 pound, if relative extension is more or equal to 675%. Laminate structures contain at least one layer of nonwoven material "spunbond".

EFFECT: structures have combination of low value bending module with high value of flaking resistance.

47 cl, 6 dwg, 11 tbl, 88 ex

FIELD: chemistry.

SUBSTANCE: method involves preparation of two solutions of a mixture of 5(6)-amino-2(para-aminophenyl)benzimidazole with 5(6)-amino-2(para-iminoquinone)benziimide in dimethylacetamide which contains lithium chloride, and then addition of paraphenylenediamine and an equimolar amount of terephthaloyl chloride to the first solution, and to the second solution - an equimolar amount of a dianhydride of pyromellitic acid. Said solutions are mixed at room temperature until formation of a spinning solution with dynamic viscosity of 300-600 P and concentratio of 3.5-4.0 wt %. The solution is filtered, vacuum treated and formed in a water-salt or water-alcohol settling bath, dried and thermally treated in free state. Industrial fireproof ballistic fabric is then produced from the obtained fibres. Threads obtained according to the invention have elementary fibre diametre higher than 10 mcm, rupture resistance not lower than 280 cN/tex and relative elongation of 3.8-4.5%.

EFFECT: invention enables to obtain fibres, threads, films with high elasticity while retaining good strength properties.

2 cl, 3 tbl, 4 ex

FIELD: chemistry.

SUBSTANCE: method involves uniaxial drawing of a polymer article with an elongated shape in a medium with subsequent removal of the medium from the volume of the article while holding the article in a pulled state in the drawing direction. The polymer used is a partially crystalline polymer with degree of crystallinity over 10%. The medium used is a gas in a supercritical state, and the medium is removed from the volume of the article by lowering pressure to a value below the critical value. The polymer article with elongated shape used can be any object selected from a film, fibre, tape, pipe or rod.

EFFECT: invention simplifies the method of producing nanoporous polymers with open pores, reduces fire hazard and improves ecological indices of the method while retaining high parametre values of volume porosity and permeability of obtained polymers.

6 cl, 2 ex

FIELD: chemistry.

SUBSTANCE: present invention refers to fibre dull polish ensured by mixed mineral additives in raised polymer thermoplastic compositions. Associated mineral additives contain at least two mineral additives chosen from the group containing zinc sulphide, titanium dioxide, barium sulphate, silicon dioxide, alumina, kaolin, calcium carbonate, calcium sulphate, mat clay. The polymer composition for product spinning as filaments, fibres, filament fibres contains associated mineral additives 2 wt % to 4 wt %.

EFFECT: high dulling factor of thermoplastic polymers.

16 cl, 2 tbl, 7 ex

FIELD: polymer materials.

SUBSTANCE: invention relates to technology of preparing elastic polymeric elements used in curable compositions and can be used in production of composites based on curable binders and reinforced with fibers for use in aircraft industry and in construction. Elastic polymeric element is in solid phase and undergoes phase transfer into liquid phase when dissolved in contact with component of polymeric matrix of curable composition. Dissolution temperature is below temperature of the beginning of gelation and/or composition setting. Element is prepared by formation of melt, extrusion, drawing, processing involving heating upon stretching, and cooling. Element is converted into substrate via stitching, binding, pinching, winding and so forth. Curable composition contains elastic polymeric element or substrate, curable polymeric matrix, and other additives.

EFFECT: improved physico-mechanical characteristics of products.

53 cl, 31 dwg, 11 tbl, 28 ex

The invention relates to a method of forming fibers from a dispersion of poly(tetrafluoroethylene) or related polymers or molding of the variance shaped products, in which the structure of the sintered fluorinated polymer is essentially free from technological salts, acids and other impurities

The invention relates to compositions for energy conversion, in addition to the electrical energy into mechanical energy, which can effectively absorb and absorb energy, such as kinetic, thermal and/or electrical, with the exception of optical energy

FIELD: chemistry.

SUBSTANCE: first step includes obtaining low-hydroxylated insoluble fullerenols by reacting concentrated fullerene solution in o-xylene with aqueous ammonia solution in the presence of a tetrabutylammonium hydroxide phase-transfer catalyst at 35-40°C. At the second step, the obtained low-hydroxylated insoluble fullerenols are hydroxylated to transform them into a water-soluble form by mixing with 6-15% aqueous hydrogen peroxide solution and heating for 4-5 hours at 65°C. Water-soluble fullerenols are then precipitated from an alcohol-containing solution.

EFFECT: simplifying the method while preserving quality characteristics and full extraction of the end product.

2 cl, 1 dwg, 4 tbl, 3 ex

FIELD: chemistry.

SUBSTANCE: invention relates to nanotechnology, particularly a method of producing aspirin nanocapsules in a carrageenan envelope. The disclosed method includes preparing an aspirin suspension in benzene; dispersing the obtained mixture into a carrageenan suspension in butanol in the presence of an E472c preparation while mixing at 1000 rps; adding tetrachloromethane; filtering the obtained nanocapsule suspension and drying at room temperature.

EFFECT: method provides a simpler and faster process of producing nanocapsules and increases mass output.

1 dwg, 4 ex

FIELD: chemistry.

SUBSTANCE: invention relates to encapsulation, particularly to a method of producing albendazole nanocapsules in a sodium alginate envelope. The disclosed method includes adding albendazole to a sodium alginate suspension in hexane in the presence of an E472c preparation while mixing at 1000 rps. The weight ratio of albendazole and sodium alginate is 1:3 or 3:1. Further, 1,2-dichloroethane is added. The obtained suspension of nanocapsules is filtered, washed and dried. The process of producing the nanocapsules is carried out at 25°C for 20 minutes.

EFFECT: invention provides a simpler and faster process of producing nanocapsules, reduces losses during production thereof (high mass output).

3 ex, 1 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to encapsulation, particularly a method of producing resveratrol nanocapsules in an envelope made of low- or highly esterified apple or citrus pectin. According to the disclosed method, resveratrol is dispersed in a suspension of low- or highly esterified apple or citrus pectin in benzene in the presence of an E472c preparation while stirring at 1000 rps. Tetrachloromethane is then added. The obtained suspension of nanocapsules is filtered and dried. The process of producing the nanocapsules is carried out at 25°C for 10 minutes.

EFFECT: invention provides a simpler and faster process of producing nanocapsules, reduces losses during production thereof (high mass output).

9 ex, 1 dwg

FIELD: nanotechnology.

SUBSTANCE: according to the invention method, albendazole is added to the suspension of sodium alginate in butanol in the presence of the preparation E472s when stirring at 1000 revolutions per second. The mass ratio of albendazole and sodium alginate is 1:3 or 3:1. Then acetonitrile is added. The resulting suspension of the nanocapsules is filtered, washed, and dried. The process of production of nanocapsules is carried out at 25°C for 20 min.

EFFECT: simplification and acceleration of the process of production of nanocapsules, reduction of losses in their production.

1 dwg, 2 ex

FIELD: chemistry.

SUBSTANCE: according to the method a suspension of resveratrol in heptane was dispersed into a suspension of xanthan gum in butanol in the presence of E472c under stirring at the rate of 1000 rev/s. A mixture of benzene and water taken at a volume ratio of 5:1 or 3:1 was added to the said suspension. The resulted suspension of nanocapsules was filtered, washed and dried. The process was performed at a temperature of 25°C within 10 min.

EFFECT: simplified and fast process of nanocapsule production, reduced process losses.

4 ex, 2 dwg

FIELD: nanotechnology.

SUBSTANCE: suspension of aspirin in benzene is produced. The resulting mixture is dispersed into suspension of sodium alginate in butanol in the presence of the preparation E472s when stirring at 1000 rpm/sec. Then chloroform is poured, the resulting suspension of nanocapsules is filtered and dried at room temperature.

EFFECT: simplification and acceleration of the process of production of the nanocapsules, and increase in the yield by weight.

1 dwg, 4 ex

FIELD: medicine.

SUBSTANCE: invention represents a method for preparing a sterile nanoemulsion of perfluororganic compounds (PFOC) involving: adding a PFOC mixture to an aqueous solution of a stabilising agent; homogenising the PFOC mixture with the aqueous solution of the stabilising agent to produce a PFOC pre-emulsion; mixing the PFOC pre-emulsion with a salt-water solution to produce the PFOC nanoemulsion; keeping the PFOC nanoemulsion at a temperature from 2 to 10°C for at least 18 hours. The method can be also implemented as follows: pre-filling a circulation loop of a PFOC nanoemulsion generating plant with the aqueous solution of the stabilising agent; adding the PFOC mixture to the aqueous solution of the stabilising agent; homogenising the PFOC mixture with the aqueous solution of the stabilising agent to produce the PFOC pre-emulsion; mixing the PFOC pre-emulsion with the salt-water solution to produce the PFOC nanoemulsion.

EFFECT: higher stability of the PFOC emulsion and prolonging the storage life.

30 cl, 7 ex, 5 tbl, 1 dwg

FIELD: nanotechnology.

SUBSTANCE: shell of the nanocapsules is used as apple or citrus high- or low-esterified pectin, and the core - as L-arginine. According to the inventive method, L-arginine is suspended in benzene, the resulting mixture is dispersed into a suspension of apple or citrus high- or low-esterified pectin in benzene in the presence of the preparation E472s while stirring 1000 revolutions per second. Then carbon tetrachloride is added, the resulting suspension of the nanocapsules is filtered and dried at room temperature. The process is carried out for 15 minutes.

EFFECT: simplification and acceleration of the process of producing the nanocapsules, and increase in the yield by weight.

6 ex

FIELD: nanotechnology.

SUBSTANCE: method of production of nanocapsules of vitamin in sodium alginate is characterized in that the shell is used as sodium alginate, and the core - as the vitamin, in a weight ratio of core:shell as 1:3. According to the method of preparing the nanocapsules the vitamin is added to a suspension of sodium alginate in benzene in the presence of the preparation E472s while stirring at 1300 rev/sec. Then hexane is added, the resulting suspension is filtered and dried at room temperature.

EFFECT: simplification and acceleration of the process of production of the nanocapsules, and increase in the yield by weight.

3 dwg, 8 ex

Extruder // 2541020

FIELD: machine building.

SUBSTANCE: extruder contains a cylindrical casing with forming head and a feeder, and screw conveyer on the drive shaft. At that the extruder contains at least one slider-crank mechanism with post connected with cylindrical casing.

EFFECT: higher productivity of the extruder.

5 cl, 4 dwg

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