Low-temperature high-toughness thermoplastic elastomer and preparation method thereof
By adding styrene copolymer and modified carbon nanotubes to thermoplastic elastomers (TPE), the problem of degradation of mechanical properties of TPE in low temperature environments is solved, and the effect of improving its low temperature toughness is achieved.
Patent Information
- Application Number
- CN202411800069.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-09
- Publication Date
- 2025-03-28
AI Technical Summary
Thermoplastic elastomers (TPEs) have decreased mechanical properties in extremely cold environments, especially in low temperature conditions. Their flexibility and impact resistance are significantly weakened, limiting their use in cold areas or in low temperature environments.
By adding styrene copolymers and modified carbon nanotubes to TPE, specific melt blending processes and additives (such as ammonium persulfate) are used to improve the low-temperature toughness of TPE.
It significantly improves the flexibility and impact strength of TPE under low temperature conditions, extending its application range in cold environments.
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Abstract
Description
Technical Field
[0001] The invention relates to a low-temperature high-toughness thermoplastic elastomer and a preparation method thereof. Background Art
[0002] With the development of material science, thermoplastic elastomer (TPE), as a new type of polymer material between traditional rubber and resin, has gradually become the focus of attention in industry and academia. TPE is known as the third generation of rubber due to its unique properties, such as high rubber elasticity and good processing performance. It is widely used in many fields such as automobiles, electronics, medical treatment, and construction. It can not only replace part of traditional rubber and reduce dependence on natural resources, but also significantly improve the toughness and physical properties of plastics, providing greater flexibility for product design.
[0003] However, although TPE performs well in room temperature applications, its mechanical properties tend to decline significantly in extremely cold environments, especially under low temperature conditions, where the flexibility and impact strength of TPE are significantly weakened. This phenomenon limits the use of TPE in cold areas or low temperature environments, such as winter sports equipment and special engineering applications that need to maintain stability in low temperature environments.
[0004] In order to solve the above problems, the present invention prepares a low-temperature high-toughness thermoplastic elastomer. Summary of the invention
[0005] The purpose of the present invention is to provide a low-temperature high-toughness thermoplastic elastomer and a preparation method thereof, so as to solve the technical problems mentioned in the above background technology.
[0006] The technical solution for achieving the purpose of the present invention is: A low-temperature high-toughness thermoplastic elastomer comprises, by weight, 45-55 parts by weight of TPE, 45-55 parts by weight of styrene copolymer, 0.4-0.6 parts by weight of modified carbon nanotubes, and 0.4-0.8 parts by weight of ammonium persulfate.
[0007] Furthermore, the styrene copolymer is obtained by copolymerizing trichlorosilane-modified styrene monomer and double-terminated hydroxyl polydimethylsiloxane.
[0008] Furthermore, the styrene monomers include 2-aminostyrene, 1,4-p-phenylenediamine, and 2,5-diethylenetriamine.
[0009] Furthermore, the modified carbon nanotubes are obtained by modifying carbon nanotubes with p-aminophenyltrimethoxysilane.
[0010] Furthermore, a method for preparing a low-temperature high-toughness thermoplastic elastomer comprises the following preparation steps: (1) Weigh the weight of each raw material component mentioned above; (2) Place TPE, styrene copolymer and modified carbon nanotubes in an internal mixer and melt-blend them at 190-210°C for 6-8 min, then add 500 parts by mass of 1M hydrochloric acid solution, cool to 70-80°C, add ammonium persulfate, continue to cool to 40-50°C and continue to mix for 3-4 h, then heat to 190-210°C and continue to melt-blend for 6-8 min to obtain a low-temperature high-toughness thermoplastic elastomer, wherein the speed of the internal mixer is 50-60 rpm.
[0011] Furthermore, the preparation steps of the styrene copolymer are as follows: dissolving 1.5 to 2 parts by mass of double-terminal hydroxyl polydimethylsiloxane in 100 parts by mass of cyclohexane to obtain a cyclohexane solution of double-terminal hydroxyl polydimethylsiloxane; under nitrogen protection, mixing the cyclohexane solution of double-terminal hydroxyl polydimethylsiloxane with 6 to 8 parts by mass of trichlorosilane-modified polystyrene, reacting at 24 to 26° C. for 23 to 25 hours, precipitating with ethanol, and vacuum drying at 70° C. for 24 hours to obtain a styrene copolymer.
[0012] Furthermore, the preparation method of the trichlorosilane-modified polystyrene is as follows: at 59-61° C., 200 parts by mass of pretreated styrene monomer are added to 4000 parts by mass of cyclohexane, 8-10 parts by mass of sec-butyl lithium initiator are added under nitrogen protection conditions, the reaction is carried out at 0.24-0.26 MPa for 55-65 minutes, ethanol is added for precipitation, vacuum drying is carried out at 70° C. for 24 hours, and then the reaction is continued under nitrogen protection conditions with 8-10 parts by mass of methyltrichlorosilane at 59-61° C. for 5-7 hours, the solvent is removed by reduced pressure distillation, and then the mixture is added to 1000 parts by mass of 1M sodium hydroxide solution, the temperature is raised to 80-90° C., the reaction is stirred for 2-4 hours, and the mixture is filtered, washed, and dried to obtain trichlorosilane-modified polystyrene.
[0013] Furthermore, the preparation steps of the pretreated styrene monomer are as follows: 1,4-p-phenylenediamine, 2,5-diethene, 2-aminostyrene and glacial acetic acid are mixed in a mass ratio of 1:1:7-8, heated to 95-105°C for reaction for 3-5h, cooled and filtered, washed and dried to obtain the pretreated styrene monomer.
[0014] Furthermore, the preparation method of the modified carbon nanotubes is as follows: first, the carbon nanotubes are added to concentrated nitric acid and ultrasonically dispersed for 25 to 35 minutes, then refluxed at 108 to 112° C. for 5 to 7 hours, filtered, washed, and dried to obtain acidified carbon nanotubes; 2 parts by mass of the acidified carbon nanotubes and 0.15 to 0.25 parts by mass of p-aminophenyltrimethoxysilane are added to 50 parts by mass of toluene solvent and ultrasonically dispersed for 25 to 35 minutes, then refluxed at 98 to 102° C. for 5.5 to 6.5 hours, filtered, washed, and dried to obtain modified carbon nanotubes.
[0015] Furthermore, the concentration of concentrated nitric acid is 65-68%.
[0016] By adopting the above technical solution, the present invention has the following beneficial effects: (1) The present invention improves the low-temperature toughness of thermoplastic elastomer TPE by adding styrene copolymer and modified carbon nanotubes to the thermoplastic elastomer TPE.
[0017] (2) Polydimethylsiloxane (PDMS) has the advantages of good low-temperature toughness, excellent lubricity, high heat resistance, and certain flame retardant effect, but the solubility parameters of PDMS and TPE are different. The styrene copolymer of the present invention is obtained by copolymerization of trichlorosilane-modified styrene monomer and double-terminated hydroxyl polydimethylsiloxane; wherein the styrene monomer includes 2-aminostyrene, 1,4-p-phenylenediamine, and 2,5-diethylene; methyltrichlorosilane is firstly grafted with the unsaturated bond of the styrene monomer through Si-Cl bond to form trichlorosilane-modified styrene monomer, and the hydroxyl group on the double-terminated hydroxyl polydimethylsiloxane reacts with the Si-Cl bond of the trichlorosilane-modified styrene monomer to form a styrene and polydimethylsiloxane block copolymer. When mixing, the good compatibility between polystyrene and thermoplastic elastomer TPE is utilized to uniformly disperse polydimethylsiloxane in TPE, thereby enhancing the interface interaction and the low-temperature toughness of the thermoplastic elastomer TPE.
[0018] (3) Carbon nanotubes are often used to strengthen and toughen TPE, mainly because when TPE is deformed by force, the rigid particles can act as stress concentration points, causing the surrounding matrix to yield, thereby consuming a large amount of energy and producing a strengthening and toughening effect. However, carbon nanotubes have poor dispersibility in TPE and are easy to agglomerate, which can easily affect the mechanical properties of TPE. The present invention uses p-aminophenyltrimethoxysilane to modify carbon nanotubes. After TPE, styrene copolymer and modified carbon nanotubes are blended, the aniline on the modified carbon nanotubes reacts and polymerizes with aniline, 2-aminostyrene, 1,4-p-phenylenediamine and 2,5-diethylenetriamine on the styrene copolymer to form polyaniline. The carbon nanotubes are evenly dispersed in the thermoplastic elastomer TPE, thereby enhancing the low-temperature toughness and antistatic properties of the polyaniline. DETAILED DESCRIPTION
[0019] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with specific implementation methods.
[0020] The following embodiments are only used to more clearly illustrate the technical solutions of the present invention, and are not intended to limit the protection scope of the present invention.
[0021] Some of the raw materials of the embodiments of the present invention and the comparative examples are as follows: TPE uses Elexar® EL-8431 from Teknor Apex.
[0022] The carbon nanotubes are from Qingdao Taige New Material Technology Co., Ltd., brand GTR-300, with an aspect ratio of 800~ 1000's of products.
[0023] (Example 1) A method for preparing a low-temperature high-toughness thermoplastic elastomer comprises the following preparation steps: 45 parts by mass of TPE, 45 parts by mass of styrene copolymer and 0.4 parts by mass of modified carbon nanotubes were placed in an internal mixer and melt-blended at 190°C for 6 minutes, followed by adding 500 parts by mass of 1M hydrochloric acid solution, cooling to 70°C, adding 0.4 parts by mass of ammonium persulfate, continuing to cool to 40°C and mixing for 3 hours, and then heating to 190°C and continuing to melt-blend for 6 minutes to obtain a low-temperature high-toughness thermoplastic elastomer, wherein the speed of the internal mixer is 50 rpm.
[0024] The preparation steps of the styrene copolymer are as follows: dissolving 1.5 parts by mass of double-terminal hydroxyl polydimethylsiloxane in 100 parts by mass of cyclohexane to obtain a cyclohexane solution of double-terminal hydroxyl polydimethylsiloxane; under nitrogen protection, mixing the above-obtained cyclohexane solution of double-terminal hydroxyl polydimethylsiloxane with 6 parts by mass of trichlorosilane-modified polystyrene, reacting at 24°C for 23 hours, precipitating with ethanol, and vacuum drying at 70°C for 24 hours to obtain a styrene copolymer.
[0025] The preparation method of the trichlorosilane-modified polystyrene is as follows: at 59° C., 200 parts by mass of pretreated styrene monomer are added to 4000 parts by mass of cyclohexane, 8 parts by mass of sec-butyl lithium initiator are added under nitrogen protection, reacting for 55 minutes at 0.24 MPa, adding ethanol for precipitation, vacuum drying at 70° C. for 24 hours, then continuing to react with 8 parts by mass of methyltrichlorosilane at 59° C. for 5 hours under nitrogen protection, removing the solvent by reduced pressure distillation, then adding to 1000 parts by mass of 1M sodium hydroxide solution, heating to 80° C., stirring for reaction for 2 hours, filtering, washing and drying to obtain trichlorosilane-modified polystyrene.
[0026] The preparation steps of the pretreated styrene monomer are as follows: 1,4-p-phenylenediamine, 2,5-diethene, 2-aminostyrene and glacial acetic acid are mixed in a mass ratio of 1:1:7, heated to 95°C for reaction for 3h, filtered after cooling, washed and dried to obtain the pretreated styrene monomer.
[0027] The preparation method of the modified carbon nanotubes is as follows: first, the carbon nanotubes are added to concentrated nitric acid for ultrasonic dispersion for 25 minutes, then refluxed at 108° C. for 5 hours, filtered, washed, and dried to obtain acidified carbon nanotubes; 2 parts by mass of the acidified carbon nanotubes and 0.15 parts by mass of p-aminophenyltrimethoxysilane are added to 50 parts by mass of toluene solvent for ultrasonic dispersion for 25 minutes, then refluxed at 98° C. for 5.5 hours, filtered, washed, and dried to obtain modified carbon nanotubes.
[0028] The concentration of the concentrated nitric acid is 65%.
[0029] (Example 2) A method for preparing a low-temperature high-toughness thermoplastic elastomer comprises the following preparation steps: 50 parts by mass of TPE, 50 parts by mass of styrene copolymer and 0.5 parts by mass of modified carbon nanotubes were placed in an internal mixer and melt-blended at 200°C for 7 minutes, followed by adding 500 parts by mass of 1M hydrochloric acid solution, cooling to 75°C, adding 0.6 parts by mass of ammonium persulfate, continuing to cool to 45°C and mixing for 3.5 hours, and then heating to 200°C and continuing to melt-blend for 7 minutes to obtain a low-temperature high-toughness thermoplastic elastomer, wherein the speed of the internal mixer is 55 rpm.
[0030] The preparation steps of the styrene copolymer are as follows: dissolving 1.8 parts by mass of double-terminal hydroxyl polydimethylsiloxane in 100 parts by mass of cyclohexane to obtain a cyclohexane solution of double-terminal hydroxyl polydimethylsiloxane; under nitrogen protection, mixing the cyclohexane solution of double-terminal hydroxyl polydimethylsiloxane with 7 parts by mass of trichlorosilane-modified polystyrene, reacting at 25° C. for 24 hours, precipitating with ethanol, and vacuum drying at 70° C. for 24 hours to obtain a styrene copolymer.
[0031] The preparation method of the trichlorosilane-modified polystyrene is as follows: at 60° C., 200 parts by mass of pretreated styrene monomer are added to 4000 parts by mass of cyclohexane, 9 parts by mass of sec-butyl lithium initiator are added under nitrogen protection, reacting for 60 minutes at 0.25 MPa, adding ethanol for precipitation, vacuum drying at 70° C. for 24 hours, then continuing to react with 9 parts by mass of methyltrichlorosilane at 60° C. for 6 hours under nitrogen protection, removing the solvent by reduced pressure distillation, then adding to 1000 parts by mass of 1M sodium hydroxide solution, heating to 85° C., stirring for reaction for 3 hours, filtering, washing, and drying to obtain trichlorosilane-modified polystyrene.
[0032] The preparation steps of the pretreated styrene monomer are as follows: 1,4-p-phenylenediamine, 2,5-diethene, 2-aminostyrene and glacial acetic acid are mixed in a mass ratio of 1:1:7.5, heated to 100°C for reaction for 4 hours, filtered after cooling, washed and dried to obtain the pretreated styrene monomer.
[0033] The preparation method of the modified carbon nanotubes is as follows: first, the carbon nanotubes are added to concentrated nitric acid for ultrasonic dispersion for 30 minutes, then refluxed at 110° C. for 6 hours, filtered, washed, and dried to obtain acidified carbon nanotubes; 2 parts by mass of the acidified carbon nanotubes and 0.2 parts by mass of p-aminophenyltrimethoxysilane are added to 50 parts by mass of toluene solvent for ultrasonic dispersion for 30 minutes, then refluxed at 100° C. for 6 hours, filtered, washed, and dried to obtain modified carbon nanotubes.
[0034] The concentration of the concentrated nitric acid is 68%.
[0035] (Example 3) A method for preparing a low-temperature high-toughness thermoplastic elastomer comprises the following preparation steps: 55 parts by mass of TPE, 55 parts by mass of styrene copolymer and 0.6 parts by mass of modified carbon nanotubes were placed in an internal mixer and melt-blended at 210°C for 8 minutes, followed by adding 500 parts by mass of 1M hydrochloric acid solution, cooling to 80°C, adding 0.8 parts by mass of ammonium persulfate, and continuing to cool to 50°C and mixing for 4 hours, followed by heating to 210°C and continuing to melt-blend for 8 minutes to obtain a low-temperature high-toughness thermoplastic elastomer, wherein the speed of the internal mixer is 60 rpm.
[0036] The preparation steps of the styrene copolymer are as follows: dissolving 1.5-2 parts by weight of double-terminal hydroxyl polydimethylsiloxane in 100 parts by weight of cyclohexane to obtain a cyclohexane solution of double-terminal hydroxyl polydimethylsiloxane; under nitrogen protection, mixing the cyclohexane solution of double-terminal hydroxyl polydimethylsiloxane with 6-8 parts by weight of trichlorosilane-modified polystyrene, reacting at 26° C. for 25 hours, precipitating with ethanol, and vacuum drying at 70° C. for 24 hours to obtain a styrene copolymer.
[0037] The preparation method of the trichlorosilane-modified polystyrene is as follows: at 61° C., 200 parts by mass of pretreated styrene monomer are added to 4000 parts by mass of cyclohexane, 10 parts by mass of sec-butyl lithium initiator are added under nitrogen protection, the reaction is carried out at 0.26 MPa for 65 minutes, ethanol is added for precipitation, vacuum drying is carried out at 70° C. for 24 hours, and then the reaction is continued at 61° C. for 7 hours with 10 parts by mass of methyltrichlorosilane under nitrogen protection, the solvent is removed by reduced pressure distillation, and then the mixture is added to 1000 parts by mass of 1M sodium hydroxide solution, the temperature is raised to 90° C., the reaction is stirred for 4 hours, and the mixture is filtered, washed, and dried to obtain the trichlorosilane-modified polystyrene.
[0038] The preparation steps of the pretreated styrene monomer are as follows: 1,4-p-phenylenediamine, 2,5-diethylenetriamine, 2-aminostyrene and glacial acetic acid are mixed in a mass ratio of 1:1:8, heated to 105°C for reaction for 5 hours, filtered after cooling, washed and dried to obtain the pretreated styrene monomer.
[0039] The preparation method of the modified carbon nanotubes is as follows: first, the carbon nanotubes are added to concentrated nitric acid for ultrasonic dispersion for 35 minutes, then refluxed at 112° C. for 7 hours, filtered, washed, and dried to obtain acidified carbon nanotubes; 2 parts by mass of the acidified carbon nanotubes and 0.25 parts by mass of p-aminophenyltrimethoxysilane are added to 50 parts by mass of toluene solvent for ultrasonic dispersion for 35 minutes, then refluxed at 102° C. for 6.5 hours, filtered, washed, and dried to obtain modified carbon nanotubes.
[0040] The concentration of the concentrated nitric acid is 68%.
[0041] (Comparative Example 1) A method for preparing a low-temperature high-toughness thermoplastic elastomer comprises the following preparation steps: 50 parts by mass of TPE, 50 parts by mass of double-terminated hydroxyl polydimethylsiloxane, and 0.5 parts by mass of modified carbon nanotubes were placed in an internal mixer and melt-blended at 200°C for 7 minutes, followed by adding 500 parts by mass of 1M hydrochloric acid solution, cooling to 75°C, adding 0.6 parts by mass of ammonium persulfate, continuing to cool to 45°C and mixing for 3.5 hours, and then heating to 200°C and continuing to melt-blend for 7 minutes to obtain a low-temperature high-toughness thermoplastic elastomer, wherein the speed of the internal mixer is 55 rpm.
[0042] The preparation method of the modified carbon nanotubes is as follows: first, the carbon nanotubes are added to concentrated nitric acid for ultrasonic dispersion for 30 minutes, then refluxed at 110° C. for 6 hours, filtered, washed, and dried to obtain acidified carbon nanotubes; 2 parts by mass of the acidified carbon nanotubes and 0.2 parts by mass of p-aminophenyltrimethoxysilane are added to 50 parts by mass of toluene solvent for ultrasonic dispersion for 30 minutes, then refluxed at 100° C. for 6 hours, filtered, washed, and dried to obtain modified carbon nanotubes.
[0043] The concentration of the concentrated nitric acid is 68%.
[0044] (Comparative Example 2) A method for preparing a low-temperature high-toughness thermoplastic elastomer comprises the following preparation steps: 50 parts by mass of TPE, 50 parts by mass of styrene copolymer and 0.5 parts by mass of modified carbon nanotubes were placed in an internal mixer and melt-blended at 200°C for 7 minutes, followed by adding 500 parts by mass of 1M hydrochloric acid solution, cooling to 75°C, adding 0.6 parts by mass of ammonium persulfate, continuing to cool to 45°C and mixing for 3.5 hours, and then heating to 200°C and continuing to melt-blend for 7 minutes to obtain a low-temperature high-toughness thermoplastic elastomer, wherein the speed of the internal mixer is 55 rpm.
[0045] The preparation steps of the styrene copolymer are as follows: dissolving 1.8 parts by mass of double-terminal hydroxyl polydimethylsiloxane in 100 parts by mass of cyclohexane to obtain a cyclohexane solution of double-terminal hydroxyl polydimethylsiloxane; under nitrogen protection, mixing the cyclohexane solution of double-terminal hydroxyl polydimethylsiloxane with 7 parts by mass of trichlorosilane-modified polystyrene, reacting at 25° C. for 24 hours, precipitating with ethanol, and vacuum drying at 70° C. for 24 hours to obtain a styrene copolymer.
[0046] The preparation method of the trichlorosilane-modified polystyrene is as follows: at 60° C., 200 parts by mass of styrene monomer is added to 4000 parts by mass of cyclohexane, 9 parts by mass of sec-butyl lithium initiator is added under nitrogen protection, reacting for 60 minutes at 0.25 MPa, adding ethanol for precipitation, vacuum drying at 70° C. for 24 hours, then continuing to react with 9 parts by mass of methyltrichlorosilane at 60° C. for 6 hours under nitrogen protection, and removing the solvent by reduced pressure distillation to obtain trichlorosilane-modified polystyrene.
[0047] The preparation method of the modified carbon nanotubes is as follows: first, the carbon nanotubes are added to concentrated nitric acid for ultrasonic dispersion for 30 minutes, then refluxed at 110° C. for 6 hours, filtered, washed, and dried to obtain acidified carbon nanotubes; 2 parts by mass of the acidified carbon nanotubes and 0.2 parts by mass of p-aminophenyltrimethoxysilane are added to 50 parts by mass of toluene solvent for ultrasonic dispersion for 30 minutes, then refluxed at 100° C. for 6 hours, filtered, washed, and dried to obtain modified carbon nanotubes.
[0048] The concentration of the concentrated nitric acid is 68%.
[0049] (Comparative Example 3) A method for preparing a low-temperature high-toughness thermoplastic elastomer comprises the following preparation steps: 50 parts by mass of TPE, 50 parts by mass of styrene copolymer and 0.5 parts by mass of modified carbon nanotubes were placed in an internal mixer and melt-blended at 200°C for 7 minutes, followed by adding 500 parts by mass of 1M hydrochloric acid solution, cooling to 75°C, adding 0.6 parts by mass of ammonium persulfate, continuing to cool to 45°C and mixing for 3.5 hours, and then heating to 200°C and continuing to melt-blend for 7 minutes to obtain a low-temperature high-toughness thermoplastic elastomer, wherein the speed of the internal mixer is 55 rpm.
[0050] The preparation steps of the styrene copolymer are as follows: dissolving 1.8 parts by mass of double-terminal hydroxyl polydimethylsiloxane in 100 parts by mass of cyclohexane to obtain a cyclohexane solution of double-terminal hydroxyl polydimethylsiloxane; under nitrogen protection, mixing the cyclohexane solution of double-terminal hydroxyl polydimethylsiloxane with 7 parts by mass of trichlorosilane-modified polystyrene, reacting at 25° C. for 24 hours, precipitating with ethanol, and vacuum drying at 70° C. for 24 hours to obtain a styrene copolymer.
[0051] The preparation method of the trichlorosilane-modified polystyrene is as follows: at 60° C., 200 parts by mass of styrene are added to 4000 parts by mass of cyclohexane, 9 parts by mass of sec-butyl lithium initiator are added under nitrogen protection, reacting for 60 minutes at 0.25 MPa, adding ethanol for precipitation, vacuum drying at 70° C. for 24 hours, then continuing to react with 9 parts by mass of methyltrichlorosilane at 60° C. for 6 hours under nitrogen protection, removing the solvent by reduced pressure distillation, then adding to 1000 parts by mass of 1M sodium hydroxide solution, heating to 85° C., stirring for reaction for 3 hours, filtering, washing, and drying to obtain trichlorosilane-modified polystyrene.
[0052] The preparation method of the modified carbon nanotubes is as follows: first, the carbon nanotubes are added to concentrated nitric acid for ultrasonic dispersion for 30 minutes, then refluxed at 110° C. for 6 hours, filtered, washed, and dried to obtain acidified carbon nanotubes; 2 parts by mass of the acidified carbon nanotubes and 0.2 parts by mass of p-aminophenyltrimethoxysilane are added to 50 parts by mass of toluene solvent for ultrasonic dispersion for 30 minutes, then refluxed at 100° C. for 6 hours, filtered, washed, and dried to obtain modified carbon nanotubes.
[0053] The concentration of the concentrated nitric acid is 68%.
[0054] (Comparative Example 4) A method for preparing a low-temperature high-toughness thermoplastic elastomer comprises the following preparation steps: 50 parts by mass of TPE, 50 parts by mass of styrene copolymer and 0.5 parts by mass of carbon nanotubes were placed in an internal mixer and melt-blended at 200°C for 7 minutes, followed by adding 500 parts by mass of 1M hydrochloric acid solution, cooling to 75°C, adding 0.6 parts by mass of ammonium persulfate, and continuing to cool to 45°C and mixing for 3.5 hours, and then heating to 200°C and continuing to melt-blend for 7 minutes to obtain a low-temperature high-toughness thermoplastic elastomer, wherein the speed of the internal mixer is 55 rpm.
[0055] The preparation steps of the styrene copolymer are as follows: dissolving 1.8 parts by mass of double-terminal hydroxyl polydimethylsiloxane in 100 parts by mass of cyclohexane to obtain a cyclohexane solution of double-terminal hydroxyl polydimethylsiloxane; under nitrogen protection, mixing the cyclohexane solution of double-terminal hydroxyl polydimethylsiloxane with 7 parts by mass of trichlorosilane-modified polystyrene, reacting at 25° C. for 24 hours, precipitating with ethanol, and vacuum drying at 70° C. for 24 hours to obtain a styrene copolymer.
[0056] The preparation method of the trichlorosilane-modified polystyrene is as follows: at 60° C., 200 parts by mass of pretreated styrene monomer are added to 4000 parts by mass of cyclohexane, 9 parts by mass of sec-butyl lithium initiator are added under nitrogen protection, reacting for 60 minutes at 0.25 MPa, adding ethanol for precipitation, vacuum drying at 70° C. for 24 hours, then continuing to react with 9 parts by mass of methyltrichlorosilane at 60° C. for 6 hours under nitrogen protection, removing the solvent by reduced pressure distillation, then adding to 1000 parts by mass of 1M sodium hydroxide solution, heating to 85° C., stirring for reaction for 3 hours, filtering, washing, and drying to obtain trichlorosilane-modified polystyrene.
[0057] The preparation steps of the pretreated styrene monomer are as follows: 1,4-p-phenylenediamine, 2,5-diethene, 2-aminostyrene and glacial acetic acid are mixed in a mass ratio of 1:1:7.5, heated to 100°C for reaction for 4 hours, filtered after cooling, washed and dried to obtain the pretreated styrene monomer.
[0058] The concentration of the concentrated nitric acid is 68%.
[0059] (Comparative Example 5) A method for preparing a low-temperature high-toughness thermoplastic elastomer comprises the following preparation steps: 50 parts by mass of TPE, 50 parts by mass of styrene copolymer and 0.5 parts by mass of modified carbon nanotubes were put into an internal mixer and melt-blended at 200° C. for 7 minutes to obtain a low-temperature high-toughness thermoplastic elastomer, wherein the speed of the internal mixer was 55 rpm.
[0060] The preparation steps of the styrene copolymer are as follows: dissolving 1.8 parts by mass of double-terminal hydroxyl polydimethylsiloxane in 100 parts by mass of cyclohexane to obtain a cyclohexane solution of double-terminal hydroxyl polydimethylsiloxane; under nitrogen protection, mixing the cyclohexane solution of double-terminal hydroxyl polydimethylsiloxane with 7 parts by mass of trichlorosilane-modified polystyrene, reacting at 25° C. for 24 hours, precipitating with ethanol, and vacuum drying at 70° C. for 24 hours to obtain a styrene copolymer.
[0061] The preparation method of the trichlorosilane-modified polystyrene is as follows: at 60° C., 200 parts by mass of pretreated styrene monomer are added to 4000 parts by mass of cyclohexane, 9 parts by mass of sec-butyl lithium initiator are added under nitrogen protection, reacting for 60 minutes at 0.25 MPa, adding ethanol for precipitation, vacuum drying at 70° C. for 24 hours, then continuing to react with 9 parts by mass of methyltrichlorosilane at 60° C. for 6 hours under nitrogen protection, removing the solvent by reduced pressure distillation, then adding to 1000 parts by mass of 1M sodium hydroxide solution, heating to 85° C., stirring for reaction for 3 hours, filtering, washing, and drying to obtain trichlorosilane-modified polystyrene.
[0062] The preparation steps of the pretreated styrene monomer are as follows: 1,4-p-phenylenediamine, 2,5-diethene, 2-aminostyrene and glacial acetic acid are mixed in a mass ratio of 1:1:7.5, heated to 100°C for reaction for 4 hours, filtered after cooling, washed and dried to obtain the pretreated styrene monomer.
[0063] The preparation method of the modified carbon nanotubes is as follows: first, the carbon nanotubes are added to concentrated nitric acid for ultrasonic dispersion for 30 minutes, then refluxed at 110° C. for 6 hours, filtered, washed, and dried to obtain acidified carbon nanotubes; 2 parts by mass of the acidified carbon nanotubes and 0.2 parts by mass of p-aminophenyltrimethoxysilane are added to 50 parts by mass of toluene solvent for ultrasonic dispersion for 30 minutes, then refluxed at 100° C. for 6 hours, filtered, washed, and dried to obtain modified carbon nanotubes.
[0064] The concentration of the concentrated nitric acid is 68%.
[0065] Effect example Tensile properties: The low-temperature high-toughness thermoplastic elastomers prepared in the examples and comparative examples were tested for tensile properties of dumbbell-shaped specimens of low-temperature high-toughness thermoplastic elastomers in accordance with GB183 at 25°C and a relative humidity of 55%, using a universal mechanical testing machine at a tensile speed of 200 mm·s -1 ,Each test was conducted 5 times and the average value was taken.
[0066] Low temperature toughness: The impact strength of the low temperature high toughness thermoplastic elastomers prepared in the examples and comparative examples at 25 and -45°C was tested using a JJ-5.5J cantilever beam impact tester according to GB / T 1843. The samples were V-notched at an angle of 45°.
[0067] Volume resistivity: The flame-retardant PBT composite plastics prepared in the examples and comparative examples were cut into a size of 100×100×2 mm, and the resistivity was tested according to GB / T 1410 standard. Each sample was tested at least 5 times and the average value was taken.
[0068] Table 1 below shows the performance test results of the low temperature high toughness thermoplastic elastomers prepared in the examples and comparative examples:
[0069] As shown in Table 1, the low-temperature high-toughness thermoplastic elastomers prepared in Examples 1 to 3 have good low-temperature toughness and antistatic properties; The only difference between Comparative Example 1 and Example 2 is that the low-temperature high-toughness thermoplastic elastomer is prepared by using TPE, polydimethylsiloxane, modified carbon nanotubes, and ammonium persulfate; the low-temperature toughness and antistatic properties of the low-temperature high-toughness thermoplastic elastomers of Comparative Example 1 and Example 2 are compared, and the low-temperature toughness and antistatic properties of the low-temperature high-toughness thermoplastic elastomer prepared in Example 2 are better; the only difference between Comparative Example 2 and Example 2 is that the styrene monomer is not pretreated in Comparative Example 2; the low-temperature toughness and antistatic properties of the low-temperature high-toughness thermoplastic elastomers of Comparative Example 1 and Example 2 are compared, and the antistatic properties of the low-temperature high-toughness thermoplastic elastomer prepared in Example 2 are better; the only difference between Comparative Example 3 and Example 2 is that the styrene monomer of trichlorosilane-modified polystyrene uses styrene; the low-temperature high-toughness thermoplastic elastomer of Comparative Example 1 and Example 2 is Compared with the low-temperature toughness and antistatic properties of the low-temperature high-toughness thermoplastic elastomer of Example 2, the low-temperature toughness and antistatic properties of the low-temperature high-toughness thermoplastic elastomer prepared in Example 2 are better; the difference between Comparative Example 4 and Example 2 is that the low-temperature high-toughness thermoplastic elastomer is prepared by TPE, styrene copolymer, carbon nanotubes and ammonium persulfate; the low-temperature toughness and antistatic properties of the low-temperature high-toughness thermoplastic elastomer of Comparative Example 1 are compared with those of Example 2; the low-temperature toughness and antistatic properties of the low-temperature high-toughness thermoplastic elastomer prepared in Example 2 are better; the difference between Comparative Example 5 and Example 2 is that the low-temperature high-toughness thermoplastic elastomer is prepared by TPE, styrene copolymer and modified carbon nanotubes; the low-temperature toughness and antistatic properties of the low-temperature high-toughness thermoplastic elastomer of Comparative Example 1 are compared with those of Example 2; the antistatic properties of the low-temperature high-toughness thermoplastic elastomer prepared in Example 2 are better.
[0070] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.
Claims
1. A low-temperature high-toughness thermoplastic elastomer, characterized in that: In parts by weight, the raw material components include 45-55 parts by weight of TPE, 45-55 parts by weight of styrene copolymer, 0.4-0.6 parts by weight of modified carbon nanotubes, and 0.4-0.8 parts by weight of ammonium persulfate.
2. The low-temperature high-toughness thermoplastic elastomer according to claim 1, characterized in that: The styrene copolymer is obtained by copolymerizing trichlorosilane-modified styrene monomer and double-terminal hydroxyl polydimethylsiloxane.
3. The low-temperature high-toughness thermoplastic elastomer according to claim 2, characterized in that: The styrene monomers include 2-aminostyrene, 1,4-p-phenylenediamine, and 2,5-diethylenetriamine.
4. The low-temperature high-toughness thermoplastic elastomer according to claim 1, characterized in that: The modified carbon nanotubes are obtained by modifying carbon nanotubes with p-aminophenyltrimethoxysilane.
5. A method for preparing a low-temperature high-toughness thermoplastic elastomer, characterized in that: The method comprises the following preparation steps: (1) Weighing the weight proportions of each raw material component according to claim 1; (2) Place TPE, styrene copolymer and modified carbon nanotubes in an internal mixer and melt-blend them at 190-210°C for 6-8 min, then add 500 parts by mass of 1M hydrochloric acid solution, cool to 70-80°C, add ammonium persulfate, continue to cool to 40-50°C and continue to mix for 3-4 h, then heat to 190-210°C and continue to melt-blend for 6-8 min to obtain a low-temperature high-toughness thermoplastic elastomer, wherein the speed of the internal mixer is 50-60 rpm.
6. The method for preparing a low-temperature high-toughness thermoplastic elastomer according to claim 5, characterized in that: The preparation steps of the styrene copolymer are as follows: dissolving 1.5-2 parts by weight of double-terminal hydroxyl polydimethylsiloxane in 100 parts by weight of cyclohexane to obtain a cyclohexane solution of double-terminal hydroxyl polydimethylsiloxane; mixing the cyclohexane solution of double-terminal hydroxyl polydimethylsiloxane with 6-8 parts by weight of trichlorosilane-modified polystyrene under nitrogen protection, reacting at 24-26° C. for 23-25 hours, precipitating with ethanol, and vacuum drying at 70° C. for 24 hours to obtain a styrene copolymer.
7. The method for preparing a low-temperature high-toughness thermoplastic elastomer according to claim 6, characterized in that: The preparation method of the trichlorosilane-modified polystyrene is as follows: adding 200 parts by mass of pretreated styrene monomer to 4000 parts by mass of cyclohexane at 59-61° C., adding 8-10 parts by mass of sec-butyl lithium initiator under nitrogen protection, reacting for 55-65 minutes at 0.24-0.26 MPa, adding ethanol for precipitation, vacuum drying at 70° C. for 24 hours, and then continuing to react with 8-10 parts by mass of methyltrichlorosilane at 59-61° C. for 5-7 hours under nitrogen protection, removing the solvent by reduced pressure distillation, and then adding to 1000 parts by mass of 1M sodium hydroxide solution, heating to 80-90° C., stirring for reaction for 2-4 hours, filtering, washing, and drying to obtain trichlorosilane-modified polystyrene.
8. The method for preparing a low-temperature high-toughness thermoplastic elastomer according to claim 7, characterized in that: The preparation steps of the pretreated styrene monomer are as follows: 1,4-p-phenylenediamine, 2,5-diethylenetriamine, 2-aminostyrene and glacial acetic acid are mixed in a mass ratio of 1:1:7-8, heated to 95-105°C for reaction for 3-5h, cooled and filtered, washed and dried to obtain the pretreated styrene monomer.
9. The method for preparing a low-temperature high-toughness thermoplastic elastomer according to claim 5, characterized in that: The preparation method of the modified carbon nanotubes is as follows: first, the carbon nanotubes are added to concentrated nitric acid for ultrasonic dispersion for 25 to 35 minutes, then refluxed at 108 to 112° C. for 5 to 7 hours, filtered, washed, and dried to obtain acidified carbon nanotubes; 2 parts by mass of the acidified carbon nanotubes and 0.15 to 0.25 parts by mass of p-aminophenyltrimethoxysilane are added to 50 parts by mass of toluene solvent for ultrasonic dispersion for 25 to 35 minutes, then refluxed at 98 to 102° C. for 5.5 to 6.5 hours, filtered, washed, and dried to obtain modified carbon nanotubes.
10. The method for preparing a low-temperature high-toughness thermoplastic elastomer according to claim 9, characterized in that: The concentration of the concentrated nitric acid is 65-68%.