Improved composite materials

FIELD: chemistry.

SUBSTANCE: invention relates to constructive composite materials and can be used in construction, and in aerospace equipment. A solidified prepreg includes a structural layer of electrically conductive fibres and the first external layer of thermoactive resin, with the resin layer including thermoplastic particles and glassy carbon particles.

EFFECT: prepreg provides higher electrical conductivity, mechanical properties and resistance to damage, caused by strikes of lightning.

31 cl, 3 dwg, 2 tbl

 

The technical field to which the invention relates

The present invention relates to an improved in parts of the electromagnetic response of composite materials, in particular to give them resistance to damage caused by lightning strikes.

The level of technology

Composite materials are properly documented advantages compared with traditional building materials, in particular in achieving excellent mechanical properties at very low density materials. As a result, the use of such materials is becoming more common, and their uses include industry, sports and leisure to high-quality aerospace components.

Prepregs, the structure of which consists of fibers impregnated with resin, such as epoxy resin, is widely used in the production of these composite materials. Typically, the number of layers of the above prepregs stacked in the desired manner and the obtained multilayer material is cured, usually when exposed to elevated temperatures, obtaining a cured composite laminate material.

A typical composite material is formed from a multilayer material containing many polymer impregnated fiber layers, for example, carbon fibers will share with�magnificent layers of polymeric resin. Although carbon fibers have a certain electrical conductivity, the presence of the separation layer means that the electrical conductivity of the composite occurs only in the plane of the multilayer material. The electrical conductivity in the direction perpendicular to the surface of the multilayer material, the so-called z-axis direction is low.

According to the report, the low conductivity in the z axis direction contributes to the vulnerability of multilayer composite materials for electromagnetic hazards, including lightning strikes. A lightning strike can cause damage to composite materials, which can be quite expensive, and can be disastrous when subjected to design an aircraft in flight. Thus, this presents a particular problem for aircraft structures made of these composite materials.

In addition, composite materials for use in aerospace equipment must meet strict standards in terms of mechanical properties. Thus, no improvement of the electrical conductivity should not adversely affect the mechanical properties.

In the known technique, a wide variety of technologies and methods to ensure the protection of these composite materials from lightning strikes, usually �key the introduction of electrically conductive elements, which increases the mass of the composite material.

In the patent application WO 2008/056123 suggested a significant improvement in resistance to lightning stroke without significantly increasing weight or deterioration of mechanical properties due to the introduction of metal structural elements in the polymer separation layers to improve their contact with the adjacent fiber layers and create electrical pathways in the z axis direction.

In the patent EP 2053078 A1 describes a prepreg comprising electrically conductive particles and thermoplastic particles. Significant preference for the use of metal or having a metal coating conductive particles.

However, the introduction of metal in the prepregs was undesirable due to possible effects of corrosion, explosion and differences of coefficients of thermal expansion of the materials.

Summary of the invention

The present invention relates to the curable prepreg comprising a structural layer of conductive fibres and a first outer layer of a thermosetting resin, wherein the resin layer includes thermoplastic particles and glass-carbon particles.

The authors present invention found that the glass-carbon particles in the first outer layer have such an effect that when the set of such prepregs are stacked together, obra�UYa block prepregs, which includes multiple layers of conductive fibers separated polymeric separating layers, creates a high conductivity in the z axis direction while maintaining and also excellent mechanical properties due to the separation structure. In addition, since the conductive particles are metal, overcome the problems of the prior art which involve the use of metal.

It is believed that superior mechanical properties due to the separation structure are due to its layered (laminar) layout. Glass-carbon particles are in the separation layers and their effects provide electrical connection between adjacent layers of electrically conductive fibers. Thus, preferably at least 90 wt%. glass-carbon particles are located in the outer layer of resin or polymer separating layer, if the image block of the prepregs.

Thus, in another aspect, the present invention also relates to the unit of prepregs, which includes many of the prepregs, as defined in the present description, and therefore includes many of the structural layer of conductive fibres and a variety of polymer separating layers formed by the first external�them with a layer.

For example, such a block may include from 4 to 200 structural layers with a corresponding number of polymer layers. Suitable separation structure described in the patent EP 0274899.

In a preferred embodiment of the prepreg includes a second outer layer resin forming the front side of the prepreg, which is not formed by the first outer layer. The second outer layer typically has the same composition as the first outer layer and its thickness is preferably the same as the first outer layer. In this embodiment, the first and the second outer layer is combined with the receiving spacer layer, when put together, the set of such prepregs.

Such separation layers preferably have an average thickness of 15 to 50 μm. If the prepreg includes only the first outer layer of resin, it forms the whole of the separation layer in the prepreg and, thus, the average thickness is preferably from 15 to 50 μm. If the prepreg contains both the first and second outer resin layer, they combine, forming the separation layer, and therefore, the combined thickness of the first and second outer resin layer is 15 to 50 microns.

After the manufacture of the block prepreg is cured under the action of elevated temperature and optionally elevated pressure, to obtain a cured �mnogosloinyi material. It is possible to use known methods of curing, including methods of curing by means of a vacuum bag, autoclave or press.

Thermoplastic particles attach to the elastic strength of the resulting multilayer material and can consist of a wide range of materials, including polyamides, co-polyamides, polyimides, aramids, polyketone, polyetheretherketone, polyarylenes, polyesters, polyurethanes and polysulfones. Preferably thermoplastic particles comprise polyamide. Preferred materials include polyamide 6, polyamide 6/12 and nylon 12.

thermoplastic particles may be present in a wide range of levels, however, it was found that the preferred level is from 5 to 20% based on the total mass of the resin in the prepreg is preferably from 10 to 20%. Preferably, at least 90 wt%. thermoplastic particles located in the outer layer of resin or polymer separating layer, if formed unit such prepregs.

thermoplastic particles may be spherical or non-spherical, porous or non-porous. However, it is shown that the porous non-spherical, even with an irregular shape more rigid particles provide good results, particularly in regard to the impact strength. For example, preferred are particles, the sphericity which compares�t from 0.5 to 0.9.

Sphericity is a measure of how spherical particle is. It is the ratio of surface area of a sphere having the same volume as the particle to the surface area of the particle. Thus, for spherical particles, the sphericity is 1. It can be calculated by the formula ψ = (6Vp)2/3π1/3/Ap, where Vp represents the volume of the particle and Ap is the surface area of the particle.

Another convenient measure of the particle shape is the ratio of the geometric dimensions. In the present description it is defined as the ratio of the greatest diameter of the cross section and the smallest diameter of the cross section. Thus, the spherical particle has a ratio of geometrical dimensions equal to 1:1. Thermoplastic particles preferably have a ratio of the geometric dimensions of from 3:1 to 1.2:1.

Preferably thermoplastic particles have a median particle size d50 of from 5 to 50 μm, preferably from 10 to 30 microns.

Carbon is present in many forms, including graphite flakes, graphite powders, graphite particles, graphene sheets, fullerenes, carbon black and carbon nanofibers. However, only a glassy carbon (glass-carbon) particles are suitable for use in the present invention. The glassy carbon is usually not�repetitively and, at least 70% bonds formed sp2preferably, at least 80%, preferably at least 90% and most preferably nearly 100% is formed ties sp2.

Glass-carbon particles are very hard and are not destroyed in the process of mixing with the polymer. Glass-carbon particles have a very low or zero porosity and are solid and do not contain cavities. Although they are lighter, hollow particles can degrade the mechanical properties of the composite by the introduction of cavities.

Glass-carbon particles are designed to create bridges between adjacent layers of the fiber layers. However, excessive amounts of such particles can adversely affect the mechanical properties of the obtained multilayer material. Thus, glass-carbon particles preferably are present at a level of 0.3 to 2.0 wt%. in the calculation of the total mass of the resin in the prepreg is preferably from 0.5 to 1.5 wt.%, preferably from 0.5 to 1.0 wt%.

Preferably glass-carbon particles have a median particle size d50 of 10 to 50 μm, preferably from 20 to 40 microns.

It was found in particular that a narrow distribution of particle size is of particular advantage, and therefore, it is preferable that the size of at least 50 wt% glass-carbon particles were in the range of from 5 μm median particle size.

Glass-carbon particles can be spherical or nonspherical. However, it was found that spherical glass-carbon particles provide excellent conductivity and good strength of the particles. For example, preferred are particles in which the sphericity is at least 0,95. In other words, glass-carbon particles preferably have a ratio of the geometric dimensions of less than 1.1:1.

Order glass-carbon particles may carry out its bridging function, the ratio of median size of the carbon particles and the average thickness of the intermediate layer is from 0.9:1 to 1.5:1, preferably from 1:1 to 1.3:1.

It was found that the ratio of thermoplastic particles and glass-carbon particles is important to achieve as good electrical conductivity and good rigidity. Thus, the weight ratio of thermoplastic particles and glass-carbon particles is preferably from 3:1 to 50:1, preferably from 3:1 to 40:1, more preferably from 5:1 to 30:1, most preferably from 8:1 to 20:1.

The structural fibers in the fiber layers can have the same direction, having the form of a cloth or be multiaxial. Preferably the fibers are unidirectional, and their orientation is changed in the mass of the block� prepregs and/or laminates for example by positioning the fibers in adjacent layers in mutually perpendicular directions, forming a so-called location 0/90, which means that the angles between adjacent fiber layers. Of course, there are other possible locations, including the 0/+45/-45/90, among numerous other locations.

Fiber may include containing cracks (i.e. torn when stretched), selectively discontinuous or continuous fibers.

The conductive fibers can be produced from a wide variety of materials, including metallized glass, carbon, graphite, metal-coated polymers, and mixtures thereof. Preferred are carbon fiber.

thermosetting resin can be chosen from those that are traditionally known in the art, including such resins as phenol -, urea -, 1,3,5-triazine-2,4,6-triamine (melamine), bismaleimide, epoxy, vinyl ester, benzoxazinone, koinopolitia, unsaturated koinopolitia, centepide resin, or mixtures thereof.

Particularly preferred are epoxy resins, for example, monofunctional, bifunctional, trifunctional or tetrafunctional epoxy resin. Preferred difunctional epoxy resins include diglycidyl ether of bisphenol F (e.g., Araldite GY 281), diglycidyl�th ether of bisphenol A, digitalimagetoolin and mixtures thereof. Highly preferred epoxy resin is a trifunctional epoxy resin containing at least one matasareanu phenyl ring in its main chain (for example, Araldite MY 0600). Preferred tetrafunctional epoxy resin is tetrachlorodibenzodioxine (for example, Araldite MY721). A mixture of bi - and trifunctional epoxy resins are also highly preferred.

Thermosetting resin may also include one or more hardeners. Suitable curing agents include anhydrides, particularly polycarboxylic anhydrides of acids; amines, in particular aromatic amines, e.g., 1,3-diaminobenzene, 4,4'-diaminodiphenylmethane and, in particular, sulfones, such as 4,4'-diaminodiphenylsulfone (4,4'-DDS) and 3,3'-diaminodiphenylsulfone (3,3'-DDS), and phenol-formaldehyde resin. Preferred hardeners are aminosulfonyl, in particular 4,4'-DDS and 3,3'-DDS.

Additional examples of the type and structure of resin and fibers can be found in the patent application WO 2008/056123.

The prepregs according to the present invention is manufactured, as a rule, the introduction of a layer of structural fibers in contact with one or several layers of resin, usually at an elevated temperature, so that the resin flowed into the voids between the fibre�mi and impregnated them.

In one embodiment, the implementation prepare a mixture of resin, thermoplastic particles and glass-carbon particles. Then from the mixture to produce the leaves and putting them in contact with one or both sides of the structural fibers. Due to the size of the particles, they do not impregnate the fibers with resin and instead filtered, remaining in the outer layer resin. Since this method involves only one step of applying the resin, it is called by the term "one-step method".

In another embodiment of the resin containing no particles, shape of leaves and bring them into contact with one or both sides of the structural fibers. This resin impregnates the fibers and remains in a small or zero amount on the outer surfaces. Thereafter, the resin containing thermoplastic particles and glass-carbon particles, is brought into contact with one or both of the surfaces of structural fibers is impregnated. This mixture remains on the outer surface and never penetrates the fibers. Because this method uses two stages for applying the resin, it is called by the term "two-stage method".

A two-stage method is preferable, because more likely leads to a better-ordered multilayer material due to the fact that particles do not damage the fibres. This way you can get in R�due to excellent mechanical properties.

Furthermore, it is preferable to apply a two-stage method for prepreg, in which both the first and second outer layers are composed of resin. In this embodiment, the implementation of two layers of resin are brought into contact with two sides of the structural fibers. The resin impregnates the fibers and remains in a small or zero amount on the outer surfaces. Thereafter, the resin containing thermoplastic particles and glass-carbon particles, is brought into contact with both sides of the impregnated structural fibers. This method is called by the term "chetyrehlistnyj method, because put four films of resin.

The present invention is particularly suitable for use in the aerospace industry, in particular for the manufacture of panels of hulls of aircraft.

In addition to resistance to lightning, it is also desirable to reduce or prevent the phenomenon known under the name "glow near the edge" or "corona discharge", after a lightning strike. This phenomenon is caused by accumulation of electric charge at the edges of the composite structure and can become a source of ignition.

It was found that the composite materials for use in structures related to the aircraft body, may suffer from this problem of corona discharge. This problem is especially dangerous�th, if composite materials are used for producing structural parts of the fuel tank.

Thus, the present invention is ideally suitable in obtaining the cured multilayer composite material for a component of a fuel tank of an aircraft.

Hereinafter the present invention will be illustrated by way of example and with reference to the following drawings, in which

Fig.1 is a cross section through the cured multilayer composite material according to the present invention.

Fig.2 is a cross section through another cured composite multilayer material according to the present invention.

Fig.3 is a cross section through another cured composite multilayer material according to the present invention.

Examples

Produced rolls of prepreg (10×0.3 m), using different amounts and types of carbon particles. One prepreg, containing glassy carbon, was used for comparison.

Produced seven resistive panels in the form of a 12-layer materials using 0/90 layers, and cured them at 180°C for 2 hours in an autoclave at a pressure of 3 bar (0.3 MPa). In the following table 1 shows the resistance of the prepreg containing a carbon microspheres, sravnitelnogo of the prepreg, does not contain microspheres. The resistance was measured by cutting out a square panel specimens (35×35 mm) and gold plating every surface in squares. On plated samples were placed electrodes and measured current (A), using power source with a known voltage. The resistance was calculated according to Ohm's law (R=V/I).

Table 1
Material (% wt.)12345678
Araldite MY 0600 (trifunctional epoxy resin)27,96Railway tracks (27.92For 27.85Up 27.71For 27.85Up 27.71For 27.8527,00
Araldite GY 281 (bifunctional epoxy resin)24,7824,7424,6824,5624,6824,5624,6824,80/td>
PES 5003P (amplifier stiffness)15,0014,9714,9314,8514,9314,8514,9315,01
Orgasol DNatl 1002D (reinforcing the rigidity of the particle)13,48Is 13.4613,4313,3613,4313,3613,4313,50
4,4'-diaminodiphenylsulfone (aromatic hardener)Carries 18.6818,6618,6118,5218,6118,5218,6118,70
Carbon particles of the first type0,100,250,501,00----
Carbon particles of the second type ----0,501,00--
Carbon particles of the third type------0,50-
Resistance (Ohms)1,300,630,350,281,361,110,407,5

Araldite MY 0600 and GY 281 supplies firm Huntsman (UK). PES 5003P supplies firm Sumitomo. Orgasol DNatl 1002D supplied by the company Arkema. 4,4' DDS delivers firm Huntsman (UK).

Carbon particles of the first type are vysokobaricheskie particles of type 1 with size from 20 to 50 μm from Alfa Aesar (USA); their sphericity exceeds 0.99, and the median size d50 is 30 μm. Carbon particles of the second type are having an irregular shape particles Sigradur G with dimensions from 20 to 50 μm from the company HTW Hochtemperatur-Workstoffe GmbH; their spheres�knosti approximately 0,65, and the median size d50 is 29.3 μm. Carbon particles of the third type are also vysokobaricheskie with size from 20 to 50 μm from the company HTW; their sphericity exceeds 0.99, and the median size d50 is 30.5 μm. The particle size was determined using laser particle size analyzer Mastersizer from the company Malvern Instruments, using a telephoto lens with a focal length of 300 mm and the thickness of the emitting layer 2.40 mm.

As can be seen, the multilayer material comprising the glass-carbon particles, exhibit a significant decrease in electrical resistance. You'll also notice that the drop resistance is more significant for spherical particles than for particles of irregular shape. It is believed that this is due to a smaller number of contacts formed between adjacent structural layers when using irregularly shaped particles.

Fig.1, 2 and 3 represent a cross-section through a cured multilayer material according to examples 4, 3 and 6, respectively.

These images show layers of unidirectional carbon fibers oriented perpendicular to the image plane 10, and unidirectional carbon fibers oriented parallel to the image plane 12. These layers of carbon fibers separates the intermediate resin layer 14. In the intermediate resin layer 14 Mgr�Giovani a rigidity of the particle, having an irregular shape. In addition, in the intermediate layer is dispersed glass-carbon particles 16 with a high degree of sphericity.

The samples obtained according to examples 3 and 7 and comparative example 8 were subjected to various mechanical tests. The results are presented in table 2 below.

Table 2
Mechanical propertyComparative example 8Example 3Example 7
The glass transition temperature Log E' (°C) (ASTM D7028)182,0178,9183,7
Quasi-isotropic breakdown pressure (MPa) (ASTM D6484/D6484M)296300291
Directional breakdown voltage (MPa) (ASTM D5766)794845816
The ultimate tensile strength (MPa) (ASTM D3039)322732343014
The modulus of elasticity (young's modulus) (GPA) (ASTM D3039) 181,2186,4185,6
Perpendicular resistance to crack development (GIc(J/m2) (ASTM D5528)301,0302,5449
Parallel resistance to crack development (GIIc(J/m2)202326081440
Resistance to interlaminar shear (MPa) (ASTM D2344)10410692,5*
The compressive strength after impact 30 j (MPa) (ASTM D7137)285,4310,4276
* measured using a different test setup.

As can be seen, the addition of glass-carbon particles according to the present invention has no appreciable impact on the mechanical properties.

1. Curable prepreg comprising a structural layer of conductive fibres and a first outer layer of a thermosetting resin, wherein the resin layer includes thermoplastic particles and glass-carbon particles,
where termorio�tive resin selected from the group including phenol-formaldehyde, urea -, 1,3,5-triazine-2,4,6-triamine (melamine), bismaleimide, epoxy, vinyl ester, benzoxazinone, koinopolitia, unsaturated koinopolitia, centepide resin or mixtures thereof; and
thermoplastic particles comprise a thermoplastic material selected from the group comprising polyamides, co-polyamides, polyimides, aramids, polyketone, polyetheretherketone, polyarylenes, polyesters, polyurethanes and polysulfones.

2. The prepreg according to claim 1, which includes the second outer layer resin forming the front surface of the prepreg, which does not form the first outer layer.

3. The prepreg according to claim 1 or 2, wherein the total thickness of the first and, if present, the second outer resin layer is 15 to 50 microns.

4. The prepreg according to claim 1 or 2, wherein thermoplastic particles comprise polyamide.

5. The prepreg according to claim 4, wherein thermoplastic particles include polyamide 6, polyamide 6/12, polyamide 12 or mixtures thereof.

6. The prepreg according to claim 1 or 2, wherein thermoplastic particles are present at a level of from 5 to 20% based on the total mass of the resin in the prepreg is preferably from 10 to 20%.

7. The prepreg according to claim 1 or 2, wherein thermoplastic particles have a sphericity of from 0.5 to 0.9.

8. The prepreg according to claim 1 or 2, wherein thermoplastic particles have a median size hour�CI d50 of from 5 to 50 microns.

9. The prepreg according to claim 8 in which thermoplastic particles have a median particle size d50 of from 10 to 30 microns.

10. The prepreg according to claim 1 or claim 2, in which the glass-carbon particles are present at a level of 0.3 to 2.0 wt%. in the calculation of the total mass of the resin in the prepreg.

11. The prepreg according to claim 10, in which the glass-carbon particles are present at a level from 0.5 to 1.5 wt%. in the calculation of the total mass of the resin in the prepreg.

12. The prepreg according to claim 10, in which the glass-carbon particles are present at a level from 0.5 to 1.0 wt%. in the calculation of the total mass of the resin in the prepreg.

13. The prepreg according to claim 1 or 2, wherein the glass-carbon particles have a median particle size d50 of from 10 to 50 microns.

14. The prepreg according to claim 13, in which the glass-carbon particles have a median particle size d50 of 20 to 40 microns.

15. The prepreg according to claim 1 or 2, wherein the size of at least 50 wt%. glass-carbon particles is in the range from 5 μm median particle size.

16. The prepreg according to claim 1 or 2, wherein the glass-carbon particles have a sphericity factor of at least 0.95 is.

17. The prepreg according to claim 1 or 2, wherein the ratio of the median size of the carbon particles and the average thickness of the intermediate layer is from 0.9:1 to 1.5:1.

18. The prepreg according to claim 17, in which the ratio of median size of the carbon particles and the average thickness of the intermediate layer is from 1:1 to 1.3:1.

19. The prepreg according �. 1 or 2, wherein the weight ratio of thermoplastic particles and glass-carbon particles is from 3:1 to 50:1.

20. The prepreg according to claim 19, in which the weight ratio of thermoplastic particles and glass-carbon particles is from 3:1 to 40:1.

21. The prepreg according to claim 19, in which the weight ratio of thermoplastic particles and glass-carbon particles is from 5:1 to 30:1.

22. The prepreg according to claim 19, in which the weight ratio of thermoplastic particles and glass-carbon particles is from 8:1 to 20:1.

23. The prepreg according to claim 1 or 2, wherein the resin includes a bifunctional epoxy resin.

24. The prepreg according to claim 1 or 2, wherein the resin comprises trifunctional epoxy resin containing at least one meta-substituted phenyl ring in its main chain.

25. The prepreg according to claim 1 or 2, wherein the resin comprises a hardener selected from the group comprising: anhydrides, in particular anhydrides of polycarboxylic acids; amines, in particular aromatic amines and aromatic aminosulfonic; and phenol-formaldehyde resin.

26. The prepreg according to claim 25, wherein the hardener is aminosulfonyl hardener, in particular, such as 4,4'-diaminodiphenylsulfone or 3,3'-diaminodiphenylsulfone.

27. Block prepreg comprising a plurality of prepregs according to any one of claims. 1-26 and, thus, includes many structural�x layers of electrically conductive fibers and a lot of the separation layer resin, consists of the first and, if present, the second outer layer of resin is defined as indicated in claim 1 or 2.

28. Cured multilayer composite material obtained by the method of impact on the prepreg or block of prepregs according to any one of p. p. 1-27 elevated temperature and optionally elevated pressure, to obtain a cured multilayer material.

29. Design related to aircraft body comprising a cured multilayer composite material according to claim 28.

30. Design related to aircraft body according to claim 29, which represents a detail of the fuel tank of an aircraft.

31. A method of manufacturing a prepreg according to any one of claims. 1-26, comprising the bringing into contact of the resin, determined as specified in claim 1, not containing particles, with one or both of the surfaces of the structural fibers, impregnating the fibers with resin, followed by bringing into contact of the resin, determined as specified in claim 1 containing thermoplastic particles and glass-carbon particles are defined as indicated in claim 1, with one or both of the surfaces of structural fibers is impregnated.



 

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Polymer composition // 2540084

FIELD: chemistry.

SUBSTANCE: polymer composition for polymer compositional materials contains oligocyanurate, hollow microspheres, additionally contains epoxy oligomer with viscosity less than 5 Pa·s at room temperature, with the following component ratio, wt %: oligocyanurate 20-60, epoxy oligomer 5-40, hollow microspheres 23-35. Polymer composition is additionally contains fibrous filler and/or disperse filler. Also claimed is product from polymer composition.

EFFECT: obtaining polymeric composition with increased viability at room temperature, which has higher compression strength, impact strength, work temperature.

13 cl, 3 tbl, 4 ex

FIELD: chemistry.

SUBSTANCE: invention relates to prepregs, a method for production and use thereof, as well as a method of making components from composite material using said prepregs. The prepregs are made of A) at least one type of reinforcing fibres and B) at least one powdered polyurethane composition as a matrix material. Component B) contains: a) at least one urethdione group-containing curing agent based on products of polyaddition of aliphatic, (cyclo)aliphatic or cycloaliphatic polyisocyanates with urethdione groups and compounds with hydroxyl groups, which is in solid state at temperature below 40°C, in liquid state above 125°C and contains less than 5 wt % free NCO-groups and 3-25 wt % urethdione groups; b) at least one polymer with hydroxyl groups which is in solid state at temperature below 40°C, in solid state above 125°C and has a hydroxyl number of 20-200 mg KOH/g. Components a) and b) are used in a ratio of one hydroxyl group in component b) per 0.3-0.7 urethdione group in component a).

EFFECT: producing technologically effective, nontoxic polyurethane-based prepregs.

18 cl, 4 dwg

FIELD: chemistry.

SUBSTANCE: epoxy composition of hot hardening for manufacturing fibreglass plastic armouring for the reinforcement of concrete constructions includes an epoxy diane oligomer of brand ED-20 (100 wt.p.), a hardening agent - iso-methyltetrahydrophthalic anhydride (80 wt.p.) and a catalyst of the polymerisation reaction - 2,4,6,-tris(dimethylaminomethyl)phenol (1.5 wt.p.). It additionally contains carbon type nanomaterials (0.05-1.5 wt.p.), representing carbon nanotubes (CNT), or carbon nanofibres (CNF), or a mixture of carbon nanomaterials: fullerene, nanotubes, nanofibres (MCNM), or soot carbon (soot) as a modifying additive.

EFFECT: invention makes it possible to increase mechanical strength, elasticity modulus, alkali-resistance and temperature of vitrification of the obtained products.

2 tbl, 21 ex

FIELD: chemistry.

SUBSTANCE: invention relates to cyanic ester-based polymer compositions which are reinforced with fibrous filler and are used for producing structural polymer composite materials with operating temperature of up to 200°C and articles from said materials which can be used in aviation, aerospace, motorcar, ship-building and other industries. The invention also relates to prepregs which include said polymer composition and articles made from said prepregs. The cyanic ester-based polymer composition contains epoxy resin, which is a modifier and selected from: epoxy diane resin, epoxy novolac resin, nitrogen-containing epoxy resin or mixtures thereof, wherein components of the composition are in the following ratio, wt %: cyanic ester 55-95, epoxy resin 5-45. The composition can further contain a solvent selected from: acetone, ethyl acetate, isopropyl alcohol or mixtures thereof. The prepreg includes the described polymer composition and fibrous filler, wherein components of the prepreg are in the following ratio, wt %: polymer composition 30.0-50.0, fibrous filler 50.0-70.0. The fibrous filler used in the prepreg can be fabric or bundles or strips based on carbon or glass fibre. An article is made from said prepreg by moulding.

EFFECT: low viscosity of the cyanic ester-based polymer composition when processing and homogeneity of the composition, which enables processing thereof via a prepreg technique and enables to obtain water-resistant articles from polymer composite materials with improved thermomechanical properties, low coefficient of variation of physical and mechanical properties, well retained strength properties at high temperatures (up to 200°C), and reduced shrinkage of the composition during processing.

5 cl, 3 tbl, 12 ex

FIELD: chemistry.

SUBSTANCE: invention relates to composite materials with high resistance to damage caused by lighting strikes. A prepreg comprising one structural layer of electroconductive unidirectional fibres and a first external layer of cured resin, substantially free of structural fibres, and optionally a second external layer of cured resin, substantially free of structural fibres, wherein the total thickness of the first and second external resin layers at said point is at least 10 mcm on average and varies at least in the range of 50% to 120% of the average value, and where said first external layer contains electroconductive particles.

EFFECT: invention improves impact strength of the material.

19 cl, 3 dwg, 4 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to the production of composite materials. The invention includes a binding agent, its application in prepregs, and a method of obtaining the binding agent. The thermosolidified binding agent contains the following components: (A) at least, one bismaleimide in a quantity from 46 to 66 wt %, (B) 4,4'-(propane-2,2-diyl)bis(2-allylphenol) in a quantity from 18 to 40 wt %; (C) at least, one substance, selected from the group, including 4'-(propane-2,2-diyl)bis(allyloxy)benzene) and bis-(4-(allyloxy)phenyl)diphenylmethane in a quantity from 2 to 15 wt %; and (D) at least, one polyimide based on aromatic diamines and dianhydrides of aromatic tetraacids in a quantity from 5 to 25 wt %.

EFFECT: simplification and cheapening the technology of obtaining the binding agent and prepreg on its base, as well as an increase of the temperature of the binding agent vitrification with the provision of satisfactory adhesiveness.

13 cl, 2 tbl, 9 ex

FIELD: machine building.

SUBSTANCE: invention relates to manufacture of structural members exposed during operation to high temperatures, and concerns a detail from composite material with ceramic matrix and method of its manufacture. It contains a fibre frame packed with a matrix, formed by multiple layers from ceramics with inclusion of the matrix phase boundary layer deflecting cracks between two adjoining ceramic layers of the matrix. The phase boundary layer includes the first phase from the material capable to promote to deflection of crack, which reached the phase boundary layer according to the first type of propagation in a transverse direction through one of two ceramic layers of the matrix, adjoining with a phase boundary layer, in such a manner that the crack propagation proceeds according to the second type of propagation along the phase boundary layer, and the second phase formed by discrete contact sections, distributed in the phase boundary layer and capable to promote to deflection of the crack, spreading along the phase boundary layer according to the second type of propagation, in such a manner that the crack propagation is deflected and continues according to the first type of propagation in transversal direction through another ceramic layer of the matrix, adjoining with the phase boundary layer.

EFFECT: invention ensures the creation of the detail from composite material with the ceramic matrix with increased life expectancy at high temperatures in corrosive medium.

15 cl, 19 dwg, 2 ex

FIELD: textiles, paper.

SUBSTANCE: fibrous absorber of electromagnetic radiation comprises two inner layers of a mixture of dielectric and electrically conducting carbon fibers which are mechanically fastened to each other by needling. Manufacturing of the absorber is carried out from the mixture of dielectric and electrically conducting carbon fibers, in which carbon fiber is used as electrically conducting carbon fibers. Carbon fiber is used with specific insulation resistance from 1.5·10-3 to 1.0 Ohm cm, and the deviation from the average value of content of carbon fiber in 1 g of the mixture does not exceed 5% by weight. The absorber additionally comprises two outer layers of rubberised fabric. The absorber has the structure of the inner layers of a mixture of dielectric and electrically conducting carbon fibers fixed by piercing with needles with a density of piercing from above of 5÷20 cm-2, from below of 20÷100 cm-2. The absorber layers are made of rubberised fabric, on the edges they are tightly stuck to each other or connected by double-faced adhesive tape.

EFFECT: improving hygienic indicators of garments with volumetric unconnected heat retainers, change in thickness of adequately to change in conditions of the ambient environment, and reduction of specific consumption of valuable heat retainer to obtain the specified thermal insulation properties.

3 cl, 2 dwg, 1 tbl, 3 ex

FIELD: textile, paper.

SUBSTANCE: covering includes a textile element of surface 2 and a layer 1, which on the surface and at least partially is connected to this textile element of the surface. The layer 1 contains a viscoelastic polymer foam. The textile element of the surface 2 has a module of elasticity, the value of which makes from ≥0.5 N/mm2 to ≤2.5 N/mm2. In the layer 1 the viscoelastic polymer foam has deposition hardness, the value of which at 40% of compression makes from ≥1 kPa to ≤10 kPa. In the layer 1 the viscoelastic polymer foam has hysteresis, the value of which at the deposition hardness determination of 40% makes ≥20% to ≤70%.

EFFECT: method of manufacturing includes a foaming operation of the back side of the textile element of surface with the help of a reaction mixture, forming a polymer foam of the layer.

13 cl, 8 dwg

Composite material // 2428240

FIELD: process engineering.

SUBSTANCE: invention relates to composite multilayer material to be used for drinking water treatment, steam condensate treatment and purification of effluents. Proposed material comprises nonwoven material including ion-exchange fiber and knitted-fabric base. Besides, it comprises nonwoven fiber glass layer. Said ion-exchange fiber represents modified polyacrylic nitrile fiber with carboxyl, hydrazide and amino groups in amount of 1.1-1.2, 2.0-2.2 and 2.9-3.1 mmol/g, respectively. Knitted-fabric base is made from yarn composed of modified finer based on graft copolymer of polycaproamid with phosphorus methacrylate. Layer weight relationship makes 1:(1.6-1.8):(1.3-1.5), respectively.

EFFECT: improved sorption and filtration properties.

1 tbl, 4 ex

FIELD: metallurgy.

SUBSTANCE: invention refers to sheet composite material and to procedure for its fabrication. Material consists of at least one porous internal layer and of at least one shell. The porous internal layer is made out of canvas fabricated out of material of structure with open cells and consisting of random crossing reinforcing fibres bound with at least one or more not foamed thermo-plastic material. The porous internal layer contains fibres at amount of approximately from 20 % wt to 80 % wt of common weight of the said porous internal layer. The shell includes at least one of the following components: thermo-plastic film, elastomer film, metal foil, thermo-reactive coating, non-organic coating, mesh on base of fibres, non-woven cloth and woven material. The shell has ultimate oxygen index over 22 determined according to ISO 4589 and is able to withstand temperature from approximately 200°C to approximately 425°C. Also each shell covers at least part of surface of the said one porous internal layer.

EFFECT: produced material possesses reduced rate of flame spread, reduced level of smoke density, and reduced level of heat and gases release.

23 cl, 3 tbl

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