CN105440343A - Carbon nanotube modified butadiene rubber material and preparation method thereof - Google Patents
Carbon nanotube modified butadiene rubber material and preparation method thereof Download PDFInfo
- Publication number
- CN105440343A CN105440343A CN201510941911.9A CN201510941911A CN105440343A CN 105440343 A CN105440343 A CN 105440343A CN 201510941911 A CN201510941911 A CN 201510941911A CN 105440343 A CN105440343 A CN 105440343A
- Authority
- CN
- China
- Prior art keywords
- minute
- carbon nanotube
- parts
- mentioned
- carbon nanotubes
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K13/00—Use of mixtures of ingredients not covered by one single of the preceding main groups, each of these compounds being essential
- C08K13/06—Pretreated ingredients and ingredients covered by the main groups C08K3/00 - C08K7/00
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K3/00—Use of inorganic substances as compounding ingredients
- C08K3/02—Elements
- C08K3/04—Carbon
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K3/00—Use of inorganic substances as compounding ingredients
- C08K3/38—Boron-containing compounds
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K7/00—Use of ingredients characterised by shape
- C08K7/22—Expanded, porous or hollow particles
- C08K7/24—Expanded, porous or hollow particles inorganic
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K9/00—Use of pretreated ingredients
- C08K9/02—Ingredients treated with inorganic substances
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K9/00—Use of pretreated ingredients
- C08K9/04—Ingredients treated with organic substances
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K9/00—Use of pretreated ingredients
- C08K9/08—Ingredients agglomerated by treatment with a binding agent
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K2201/00—Specific properties of additives
- C08K2201/011—Nanostructured additives
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2201/00—Properties
- C08L2201/08—Stabilised against heat, light or radiation or oxydation
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Compositions Of Macromolecular Compounds (AREA)
- Carbon And Carbon Compounds (AREA)
Abstract
The invention discloses a carbon nanotube modified butadiene rubber material. The material comprises, by weight, 10-14 parts of dicapryl phthalate, 30-40 parts of carbon nanotubes, 50-60 parts of hydroxyl-terminated polybutadiene, 200-300 parts of n-methylpyrrolidone, 5-7 parts of boron oxide, 160-200 parts of butadiene rubber, 2-3 parts of inositol hexaphosphate, 2-3 parts of an antioxidant 4010, 1.3-2 parts of sulfur, 1-2 parts of diglycolamide oleate, 3-4 parts of stearic acid, 6-9 parts of graphite powder and 0.3-1 part of butylmercaptooxo stannane. The carbon nanotubes are carboxylated, and the carboxylated carbon nanotubes react with hydroxyl-terminated polybutadiene to enhance the strength of a rubber material, because a reaction of carboxyl groups on the surfaces of the carbon nanotubes and hydroxyl groups in the hydroxyl-terminated polybutadiene to make the surfaces of the carbon nanotubes be connected with the molecular chain of the hydroxyl-terminated polybutadiene through covalent bonds in order to improve the dispersibility of carbon nanotubes in a matrix, enhance the adhesion force of the carbon nanotubes with the rubber matrix and make the carbon nanotubes have a good reinforcing effect in the rubber matrix.
Description
Technical field
The present invention relates to field of rubber technology, particularly relate to a kind of carbon nano-tube modification cis-1,4-polybutadiene rubber material and preparation method thereof.
Background technology
Carbon nanotube is widely used in polymkeric substance to the heat conduction of raising polymkeric substance, conduction and physicals etc. because of the structure of its uniqueness and the physical and chemical performance of excellence.But carbon nanotube itself has very high surface free energy, easily reunites, and not easily disperses in polymeric matrix, limit its application.The surface modification treatment of carbon nanotube is one of important channel of improving its dispersive ability in the polymer and then the excellent carbon nano-tube/polymer composite material of processability;
Hydroxy-terminated polybutadienes is liquid because of it at normal temperatures, and transparency is good, the low good processability of viscosity; And it and chainextender, linking agent react the cured article that can generate tridimensional network at ambient temperature or elevated temperature, this cured article has excellent mechanical property, good oil resistant and water resistance, particularly acid and alkali-resistance, wear-resisting, low temperature resistant and electrical insulation capability is better, become output in distant pawl series of fluids rubber maximum, purposes is a kind the most widely, is mainly used in the aspects such as solid propellant tackiness agent, polyurethane elastomer, material of construction, speciality coating, tackiness agent, Embedding Material, rubber and plastic and epoxy resin modification.Hydroxy-terminated polybutadienes gives its more characteristic by modification later, improves its performance, has widened the Application Areas of hydroxy-terminated polybutadienes.
Summary of the invention
The object of the invention is exactly the defect in order to make up prior art, provides a kind of carbon nano-tube modification cis-1,4-polybutadiene rubber material and preparation method thereof.
The present invention is achieved by the following technical solutions:
A kind of carbon nano-tube modification cis-1,4-polybutadiene rubber material, it is made up of the raw material of following weight parts:
Dioctyl phthalate (DOP) 10-14, carbon nanotube 30-40, hydroxy-terminated polybutadienes 50-60, n-methyl-2-pyrrolidone 200-300, boron oxide 5-7, cis-1,4-polybutadiene rubber 160-200, myo-Inositol hexaphosphate 2-3, antioxidant 4010 2-3, sulphur 1.3-2, oleic acid diethyl amide 1-2, stearic acid 3-4, Graphite Powder 99 6-9, butanethiol tin 0.3-1.
A preparation method for described carbon nano-tube modification cis-1,4-polybutadiene rubber material, comprises the following steps:
(1) above-mentioned oleic acid diethyl amide is joined in 20-24 times of deionized water, stir, add stearic acid, Graphite Powder 99, magnetic agitation 3-5 minute, obtain stearic acid modified graphite emulsion;
(2) above-mentioned carbon nanotube is placed in its weight 40-50 doubly, massfraction is the aqueous hydrogen peroxide solution ultrasonic disperse 30-40 minute of 0.3-0.5%, add above-mentioned stearic acid modified graphite emulsion, at 70-80 DEG C, be incubated 100-120 minute, filtration, vacuum-drying, obtain pre-treatment carbon nanotube;
(3) get sulfuric acid that volume ratio is 3-4:1, salpeter solution mixing, stir, described sulfuric acid concentration is 70-75%, concentration of nitric acid is 80-85%;
(4) pre-treatment carbon nanotube obtained above is joined in above-mentioned mixed acid solution, ultrasonic 100-110 minute at 50-60 DEG C, filtration under diminished pressure, be neutral by carbon nanotube deionized water repetitive scrubbing to the filtrate obtained, the vacuum drying oven putting into 76-80 DEG C is dried, and obtains acidifying carbon nanotube;
(5) above-mentioned acidifying carbon nanotube is mixed with hydroxy-terminated polybutadienes, magnetic agitation 2-3 minute, join in said n-methyl-2-pyrrolidone, ultrasonic 10-16 minute, suction filtration, by filter cake dry 20-30 minute at 100-105 DEG C, obtains hydroxyl modification acidifying carbon nanotube;
(6) mixed with boron oxide by above-mentioned hydroxyl modification acidifying carbon nanotube, ball milling is even; Being sent to concentration is in the phosphoric acid solution of 10-15%, constant temperature dipping 120-130 minute at 150-160 DEG C, discharging, drying, sends in reactor, under nitrogen protection, thermal treatment 100-120 minute at 400-450 DEG C, cools, wears into fine powder, obtains phosphate impregnation compounded mix;
(7) above-mentioned myo-Inositol hexaphosphate is joined in 20-23 times of deionized water, stir, add butanethiol tin, phosphate impregnation compounded mix, be sent in boiling water bath, insulated and stirred 6-10 minute, discharging cools, dehydration, mixing with dioctyl phthalate (DOP), stir, is Preblend;
(8) by above-mentioned Preblend, cis-1,4-polybutadiene rubber mixing, plasticate 2-3 minute at 46-50 DEG C, add each raw material of residue, mixing 4-6 minute, is placed in two roller mills by the rubber unvulcanizate obtained, mixing 6-10 minute is supplemented at 30-40 DEG C, discharging, at room temperature parks 20-25 hour by sizing material, sends in vulcanizing press, at 150-155 DEG C, carry out sulfuration, to obtain final product.
The preparation method of described a kind of carbon nano-tube modification cis-1,4-polybutadiene rubber material, the weight of described mixed acid solution is 18-20 times of pre-treatment carbon nanotubes.
Advantage of the present invention is:
First the present invention carries out Carboxylation process to carbon nanotube, then react with hydroxy-terminated polybutadienes, the intensity of sizing material can be strengthened, this is due to the hydroxyl reaction in the carboxyl of carbon nano tube surface and hydroxy-terminated polybutadienes, carbon nano tube surface is connected by covalent linkage with hydroxy-terminated polybutadienes molecular chain, thus improve its dispersiveness in the base, and enhance the bounding force of itself and rubber matrix, make it in rubber matrix, show better reinforcing effect;
Then the carboxylic acid carbon nanotube after hydroxy-terminated polybutadienes process is mixed with boron oxide, use phosphate impregnation compounded mix, the pyrogenous origin product P 4O10 of phosphoric acid is phosphorus oxygen glass structure, introduce B2O3 in the melt, [BPO4] structural unit can be formed, glass structure is made to change rack-like into by chain, these rack-like structures are cross-linked with each other, strengthen network structure, strengthen the bonding strength with matrix, one deck coating can be covered at matrix surface, covering surfaces hole more effectively, confining surface active site, effective prevention oxidizing gas enters intrinsic silicon by micropore or crackle, effectively raise physical strength and the antioxidant property of finished product.
Embodiment
A kind of carbon nano-tube modification cis-1,4-polybutadiene rubber material, it is made up of the raw material of following weight parts:
Dioctyl phthalate (DOP) 10, carbon nanotube 30, hydroxy-terminated polybutadienes 50, n methyl-2-pyrrolidone 200, boron oxide 5, cis-1,4-polybutadiene rubber 160, myo-Inositol hexaphosphate 2, antioxidant 4010 2, sulphur 1.3, oleic acid diethyl amide 1, stearic acid 3, Graphite Powder 99 6, butanethiol tin 0.3.
A preparation method for described carbon nano-tube modification cis-1,4-polybutadiene rubber material, comprises the following steps:
(1) above-mentioned oleic acid diethyl amide is joined in 20 times of deionized waters, stir, add stearic acid, Graphite Powder 99, magnetic agitation 3 minutes, obtain stearic acid modified graphite emulsion;
(2) above-mentioned carbon nanotube is placed in its weight 40 times, massfraction be 0.3% aqueous hydrogen peroxide solution ultrasonic disperse 30 minutes, add above-mentioned stearic acid modified graphite emulsion, at 70 DEG C, be incubated 100 minutes, filtration, vacuum-drying, obtain pre-treatment carbon nanotube;
(3) get sulfuric acid that volume ratio is 3:1, salpeter solution mixing, stir, described sulfuric acid concentration is 70%, concentration of nitric acid is 80%;
(4) pre-treatment carbon nanotube obtained above is joined in above-mentioned mixed acid solution, at 50 DEG C ultrasonic 100 minutes, carbon nanotube deionized water repetitive scrubbing to the filtrate obtained was neutral by filtration under diminished pressure, the vacuum drying oven putting into 76 DEG C is dried, and obtains acidifying carbon nanotube;
(5) above-mentioned acidifying carbon nanotube is mixed with hydroxy-terminated polybutadienes, magnetic agitation 2 minutes, join in said n methyl-2-pyrrolidone, ultrasonic 10 minutes, suction filtration, by filter cake at 100 DEG C dry 20 minutes, obtain hydroxyl modification acidifying carbon nanotube;
(6) mixed with boron oxide by above-mentioned hydroxyl modification acidifying carbon nanotube, ball milling is even; Being sent to concentration is in the phosphoric acid solution of 10%, and at 150 DEG C, constant temperature floods 120 minutes, discharging, dry, and send in reactor, under nitrogen protection, at 400 DEG C, thermal treatment 100 minutes, cools, wears into fine powder, obtains phosphate impregnation compounded mix;
(7) above-mentioned myo-Inositol hexaphosphate is joined in 20 times of deionized waters, stir, add butanethiol tin, phosphate impregnation compounded mix, be sent in boiling water bath, insulated and stirred 6 minutes, discharging cools, dehydration, mixing with dioctyl phthalate (DOP), stir, is Preblend;
(8) by above-mentioned Preblend, cis-1,4-polybutadiene rubber mixing, plasticate at 46 DEG C 2 minutes, add each raw material of residue, mixing 4 minutes, the rubber unvulcanizate obtained is placed in two roller mills, supplement mixing 6 minutes at 30 DEG C, discharging, at room temperature parks 20 hours by sizing material, sends in vulcanizing press, at 150 DEG C, carry out sulfuration, to obtain final product.
The preparation method of described a kind of carbon nano-tube modification cis-1,4-polybutadiene rubber material, the weight of described mixed acid solution is 18 times of pre-treatment carbon nanotubes.
Stretch breaking strength (MPa): 17.9;
Surely modulus 100%(MPa is stretched): 2.4;
Mooney viscosity: 64;
70 DEG C × 70h air oven aging test:
Tensile strength at yield reduced rate: 4.3%, elongation at break reduced rate: 8.5%.
Claims (3)
1. a carbon nano-tube modification cis-1,4-polybutadiene rubber material, is characterized in that, it is made up of the raw material of following weight parts:
Dioctyl phthalate (DOP) 10-14, carbon nanotube 30-40, hydroxy-terminated polybutadienes 50-60, n-methyl-2-pyrrolidone 200-300, boron oxide 5-7, cis-1,4-polybutadiene rubber 160-200, myo-Inositol hexaphosphate 2-3, antioxidant 4010 2-3, sulphur 1.3-2, oleic acid diethyl amide 1-2, stearic acid 3-4, Graphite Powder 99 6-9, butanethiol tin 0.3-1.
2. a preparation method for carbon nano-tube modification cis-1,4-polybutadiene rubber material as claimed in claim 1, is characterized in that, comprise the following steps:
(1) above-mentioned oleic acid diethyl amide is joined in 20-24 times of deionized water, stir, add stearic acid, Graphite Powder 99, magnetic agitation 3-5 minute, obtain stearic acid modified graphite emulsion;
(2) above-mentioned carbon nanotube is placed in its weight 40-50 doubly, massfraction is the aqueous hydrogen peroxide solution ultrasonic disperse 30-40 minute of 0.3-0.5%, add above-mentioned stearic acid modified graphite emulsion, at 70-80 DEG C, be incubated 100-120 minute, filtration, vacuum-drying, obtain pre-treatment carbon nanotube;
(3) get sulfuric acid that volume ratio is 3-4:1, salpeter solution mixing, stir, described sulfuric acid concentration is 70-75%, concentration of nitric acid is 80-85%;
(4) pre-treatment carbon nanotube obtained above is joined in above-mentioned mixed acid solution, ultrasonic 100-110 minute at 50-60 DEG C, filtration under diminished pressure, be neutral by carbon nanotube deionized water repetitive scrubbing to the filtrate obtained, the vacuum drying oven putting into 76-80 DEG C is dried, and obtains acidifying carbon nanotube;
(5) above-mentioned acidifying carbon nanotube is mixed with hydroxy-terminated polybutadienes, magnetic agitation 2-3 minute, join in said n-methyl-2-pyrrolidone, ultrasonic 10-16 minute, suction filtration, by filter cake dry 20-30 minute at 100-105 DEG C, obtains hydroxyl modification acidifying carbon nanotube;
(6) mixed with boron oxide by above-mentioned hydroxyl modification acidifying carbon nanotube, ball milling is even; Being sent to concentration is in the phosphoric acid solution of 10-15%, constant temperature dipping 120-130 minute at 150-160 DEG C, discharging, drying, sends in reactor, under nitrogen protection, thermal treatment 100-120 minute at 400-450 DEG C, cools, wears into fine powder, obtains phosphate impregnation compounded mix;
(7) above-mentioned myo-Inositol hexaphosphate is joined in 20-23 times of deionized water, stir, add butanethiol tin, phosphate impregnation compounded mix, be sent in boiling water bath, insulated and stirred 6-10 minute, discharging cools, dehydration, mixing with dioctyl phthalate (DOP), stir, is Preblend;
(8) by above-mentioned Preblend, cis-1,4-polybutadiene rubber mixing, plasticate 2-3 minute at 46-50 DEG C, add each raw material of residue, mixing 4-6 minute, is placed in two roller mills by the rubber unvulcanizate obtained, mixing 6-10 minute is supplemented at 30-40 DEG C, discharging, at room temperature parks 20-25 hour by sizing material, sends in vulcanizing press, at 150-155 DEG C, carry out sulfuration, to obtain final product.
3. the preparation method of a kind of carbon nano-tube modification cis-1,4-polybutadiene rubber material according to claim 2, is characterized in that, the weight of described mixed acid solution is 18-20 times of pre-treatment carbon nanotubes.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510941911.9A CN105440343A (en) | 2015-12-16 | 2015-12-16 | Carbon nanotube modified butadiene rubber material and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510941911.9A CN105440343A (en) | 2015-12-16 | 2015-12-16 | Carbon nanotube modified butadiene rubber material and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN105440343A true CN105440343A (en) | 2016-03-30 |
Family
ID=55551013
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510941911.9A Pending CN105440343A (en) | 2015-12-16 | 2015-12-16 | Carbon nanotube modified butadiene rubber material and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105440343A (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103694505A (en) * | 2013-12-24 | 2014-04-02 | 苏州华东橡胶工业有限公司 | Compound carbon nanotube and rubber material and preparation method thereof |
-
2015
- 2015-12-16 CN CN201510941911.9A patent/CN105440343A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103694505A (en) * | 2013-12-24 | 2014-04-02 | 苏州华东橡胶工业有限公司 | Compound carbon nanotube and rubber material and preparation method thereof |
Non-Patent Citations (2)
| Title |
|---|
| 王中光: "碳纳米管表面包覆聚合物方法的探索及其聚合物材料的性能研究", 《青岛科技大学硕士学位论文》 * |
| 雷卓研等: "氧化硼-磷酸浸渍对中间相炭微球复合材料抗氧化及力学性能的影响", 《无机材料学报》 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103408948A (en) | Rubber composition and application thereof | |
| CN108084351A (en) | Endless-track vehicle bushing rubber material | |
| CN105419038A (en) | Composition for manufacturing compound rubber mat and preparation method of composition | |
| CN105524307A (en) | Nylon blended rubber material and preparation method thereof | |
| CN103102543B (en) | A kind of thermoplastic elastomer electric wire and cable material and preparation method thereof | |
| CN1301291C (en) | Oil resistant insulating nano-rubber | |
| CN109971047B (en) | Natural rubber-white carbon black composite material and preparation method and application thereof | |
| CN113214657B (en) | High-strength, high-conductivity and flexible soybean protein film and preparation method thereof | |
| CN105482180A (en) | Anti-corrosive butadiene rubber material and preparation method thereof | |
| CN105440350A (en) | Ageing resistant butadiene rubber material and preparation method thereof | |
| CN106832718A (en) | A kind of conducting polymer composite graphite alkene material and preparation method thereof | |
| CN111978611B (en) | High-strength conductive self-healing rubber composite material and preparation method thereof | |
| CN105440346A (en) | Lubricating butadiene rubber material and preparation method thereof | |
| CN105440353A (en) | Zirconium-based hard butadiene rubber material and preparation method thereof | |
| CN105482179A (en) | Cis-polybutadiene rubber material and preparation method thereof | |
| CN105542250A (en) | Flexible rosin-butadiene rubber material and preparation method thereof | |
| CN105440343A (en) | Carbon nanotube modified butadiene rubber material and preparation method thereof | |
| CN103387727B (en) | A kind of sealing ring that connects | |
| CN105440351A (en) | High strength butadiene rubber material and preparation method thereof | |
| CN105462001A (en) | Hydrophobic butadiene rubber material and preparation method thereof | |
| CN105482178A (en) | Macromolecular butadiene rubber material and preparation method thereof | |
| CN105440348A (en) | Phosphatized butadiene rubber material and preparation method thereof | |
| CN109824951B (en) | Modified rubber sealing element and preparation method thereof | |
| CN115181340B (en) | Electromagnetic shielding natural rubber for effectively constructing three-dimensional conductive network structure and preparation thereof | |
| CN105440352A (en) | Heatproof butadiene rubber material and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20160330 |