Preparation method of graphene / PBT master batch for sheath-core fiber and preparation method of sheath-core fiber

Abstract

The invention discloses a preparation method of a graphene / PBT (polybutylene terephthalate) master batch for a sheath-core fiber, the graphene / PBT master batch is prepared by synthesizing PBT-g-GMA (glycidyl methacrylate) as a dispersing agent of high-filling-amount graphene in a PBT matrix and combining a twin-screw extrusion process, and the problems that in the current preparation process of a high-thermal-conductivity fiber, the graphene is seriously agglomerated, and the heat conductivity of the high-thermal-conductivity fiber is poor are solved. The invention further discloses a preparation method of the skin-core fiber, and the purpose that the fiber has excellent thermal conductivity and good spinnability and mechanical property is achieved.

Description

Technical Field

[0001] This invention relates to the field of synthetic fiber technology, specifically to a method for preparing graphene / PBT masterbatch for core-sheath fibers and a method for preparing core-sheath fibers. Background Technology

[0002] Graphene boasts a thermal conductivity as high as 5000 W / (m•K), far exceeding that of most traditional thermally conductive materials. Therefore, it is highly favored in the preparation of high-thermal-conductivity fibers, endowing them with efficient heat conduction capabilities to meet the needs of many applications requiring high thermal conductivity. However, when graphene is directly added to fibers, due to its inherent properties, only a high addition amount can produce a significant thermal conductivity effect. But high addition amounts can trigger a series of chain reactions. Graphene has a strong tendency to agglomerate, making it difficult to disperse uniformly in the fiber matrix. Large amounts of aggregated graphene can disrupt the continuity of the fiber matrix, leading to obstacles in the spinning process. During spinning, the fluidity of the melt deteriorates due to graphene agglomeration, making fiber forming difficult and prone to breakage, severely impacting production efficiency and product quality. Furthermore, with increasing graphene addition, the mechanical properties of the fiber decrease significantly. Key indicators such as tensile strength and elongation at break are significantly reduced, making the fiber easily damaged during use and failing to meet the basic mechanical performance requirements of practical applications. Summary of the Invention

[0003] The purpose of this invention is to provide a method for preparing graphene / PBT masterbatch for core-sheath fibers, which mixes high-content graphene with PBT (polybutylene terephthalate) to form masterbatch, effectively solving the problem of graphene dispersion in the matrix.

[0004] The present invention also aims to provide a method for preparing core-sheath fibers, wherein the above-mentioned graphene / PBT masterbatch is used as the sheath material and combined with PET core material to form core-sheath fibers, which have both high thermal conductivity and good mechanical properties.

[0005] To achieve the above objectives, the solution of the present invention is: A method for preparing graphene / PBT masterbatch for core-sheath fibers includes the following steps: Step 1: First, according to the formula ratio, add 100 parts PBT, 1-5 parts GMA (glycidyl methacrylate), 0.1-0.5 parts DCP (diisopropylbenzene peroxide) and 0.2-0.5 parts antioxidant into a high-speed mixer and stir at room temperature to obtain mixture A; Step 2: Then, the mixture A is fed into a twin-screw extruder for grafting, extrusion, and granulation. The temperature of each section of the twin-screw extruder is controlled at 180~200℃ in the first section, 230~250℃ in the second section, 220~230℃ in the third section, and 220~230℃ in the fourth section. After water-cooled stringing and pelletizing, PBT-g-GMA is obtained. Step 3: Then, according to the formula ratio, add 10-30 parts of graphene, 60-85 parts of PBT powder and 5-10 parts of PBT-g-GMA into a high-speed mixer and stir at room temperature to obtain mixture B. Step 4: Finally, mixture B is fed into a twin-screw extruder for extrusion and granulation. The temperatures of each section of the twin-screw extruder are controlled at 220-230℃ in the first section, 230-240℃ in the second section, 240-250℃ in the third section, and 245-255℃ in the fourth section, respectively, to obtain a graphene content of 10%. wt %~30 wt % of graphene / PBT masterbatch.

[0006] In step 1, the stirring speed is 50~60 r / min, and the stirring time is 5~10 min.

[0007] In step 1, the antioxidant is antioxidant 1010 or antioxidant 1076.

[0008] In step 2, the die head temperature of the twin-screw extruder is 200~220℃, and the screw speed is 200~300 r / min.

[0009] In steps 1 and 3, the particle size of the PBT powder is 200-300 mesh.

[0010] In step 3, the stirring speed is 500~1000 r / min, and the stirring time is 10~30 min.

[0011] In step 4, the die head temperature of the twin-screw extruder is 250~260℃, and the screw speed is 100~300 r / min.

[0012] A method for preparing a core-sheath fiber includes the following steps: First, according to the formula ratio, 10-30 parts of graphene / PBT masterbatch and 70-90 parts of PET are mixed as the sheath material, and PET is used as the core material. Then, 20-40 parts of the sheath material and 60-80 parts of the core material are fed into the corresponding screws of a spinning machine for spinning to obtain the core-sheath fiber.

[0013] The spinning temperature is 270~290℃, the spinning speed is 1000~3000 m / min, the cooling air temperature is 20~30℃, and the cooling air velocity is 0.5~2 m / s.

[0014] By adopting the above technical solution, the present invention provides a method for preparing graphene-supported PBT masterbatch for core-sheath fibers. By synthesizing PBT-g-GMA as a dispersant for highly filled graphene in a PBT matrix, the method utilizes the structural characteristics of its "hydrophobic main chain - reactive side chain". The main chain has excellent compatibility with polyester matrices such as PBT, avoiding the incompatibility problem between external dispersants and the matrix. At the same time, the GMA side chain has strong reactivity, resulting in a more stable combination with graphene and a longer-lasting dispersion effect. Combined with a twin-screw extrusion process, high-content graphene and PBT are made into masterbatch, effectively solving the problem of graphene dispersion in the matrix.

[0015] This invention discloses a method for preparing core-sheath fibers. The core-sheath fibers are prepared by mixing graphene / PBT masterbatch with PET as the sheath material and PET as the core material using a composite spinning process. The fibers exhibit a thermal conductivity of 1.5~2.5 W / (m•K) and a breaking strength of 3~5 cN / dtex. These fibers demonstrate good spinning performance, with a breakage rate of less than 0.5 times / hour during the spinning process, and combine high thermal conductivity with excellent mechanical properties. Detailed Implementation

[0016] To further explain the technical solution of the present invention, the present invention will be described in detail below through specific embodiments.

[0017] Example 1 A method for preparing graphene / PBT masterbatch for core-sheath fibers includes the following steps: Step 1: First, according to the formula ratio, add 100 parts of 200-mesh PBT, 2 parts of GMA, 0.2 parts of DCP and 0.2 parts of antioxidant 1010 into a high-speed mixer and stir at 55 r / min for 6 min at room temperature to obtain mixture A. Step 2: Then, the mixture A is fed into a twin-screw extruder for grafting, extrusion and granulation. The die head temperature of the twin-screw extruder is 200℃, the screw speed is 250 r / min, and the temperature of each section is controlled at 180℃ in the first section, 200℃ in the second section, 220℃ in the third section and 230℃ in the fourth section. After water-cooled stringing and pelletizing, PBT-g-GMA is obtained. Step 3: Then, according to the formula ratio, add 15 parts of graphene, 80 parts of 200-mesh PBT powder and 5 parts of PBT-g-GMA into a high-speed mixer and stir at 600 r / min for 15 min at room temperature to obtain mixture B. Step 4: Finally, mixture B is fed into a twin-screw extruder for extrusion granulation. The die temperature of the twin-screw extruder is 250℃, the screw speed is 150 r / min, and the temperatures of each section are controlled at 220℃ for the first section, 240℃ for the second section, 250℃ for the third section, and 245℃ for the fourth section, respectively, to obtain a graphene content of 15%. wt % of graphene / PBT masterbatch.

[0018] Example 2 A method for preparing graphene / PBT masterbatch for core-sheath fibers includes the following steps: Step 1: First, according to the formula ratio, add 100 parts of 250 mesh PBT, 3 parts of GMA, 0.3 parts of DCP and 0.3 parts of antioxidant 1076 into a high-speed mixer and stir at 55 r / min for 7 min at room temperature to obtain mixture A. Step 2: Then, the mixture A is fed into a twin-screw extruder for grafting, extrusion and granulation. The die head temperature of the twin-screw extruder is 210℃, the screw speed is 260 r / min, and the temperature of each section is controlled at 180℃ in the first section, 230℃ in the second section, 230℃ in the third section, and 220℃ in the fourth section. After water-cooled stringing and pelletizing, PBT-g-GMA is obtained. Step 3: Then, according to the formula ratio, add 20 parts of graphene, 73 parts of 250-mesh PBT powder and 7 parts of PBT-g-GMA into a high-speed mixer and stir at 700 r / min for 15 min at room temperature to obtain mixture B. Step 4: Finally, mixture B is fed into a twin-screw extruder for extrusion granulation. The die temperature of the twin-screw extruder is 250℃, the screw speed is 200 r / min, and the temperatures of each section are controlled at 220℃ for the first section, 240℃ for the second section, 250℃ for the third section, and 245℃ for the fourth section, respectively, to obtain a graphene content of 20%. wt % of graphene / PBT masterbatch.

[0019] Example 3 A method for preparing a core-sheath fiber includes the following steps: First, according to the formula ratio, 20 parts of graphene / PBT masterbatch prepared in Example 1 are mixed with 80 parts of PET as the sheath material, and PET is used as the core material. Then, 30 parts of the sheath material and 70 parts of the core material are fed into the corresponding screws of a spinning machine for spinning. The spinning temperature is 280°C, the spinning speed is 2000 m / min, the spinning cooling air temperature is 25°C, and the spinning cooling air velocity is 1 m / s, thereby obtaining the core-sheath fiber.

[0020] Example 4 A method for preparing a core-sheath fiber includes the following steps: First, according to the formula ratio, 10 parts of graphene / PBT masterbatch prepared in Example 2 are mixed with 90 parts of PET as the sheath material, and PET is used as the core material. Then, 40 parts of the sheath material and 60 parts of the core material are fed into the corresponding screws of a spinning machine for spinning. The spinning temperature is 270°C, the spinning speed is 1000 m / min, the spinning cooling air temperature is 20°C, and the spinning cooling air velocity is 0.5 m / s, thereby obtaining the core-sheath fiber.

[0021] Comparative Example 1 A method for preparing graphene masterbatch for core-sheath fibers includes the following steps: First, according to the formula ratio, 15 parts of graphene, 80 parts of 200-mesh PBT powder, and 5 parts of nonionic dispersant polypyrrolidone are added to a high-speed mixer and stirred at 600 r / min for 15 min at room temperature to obtain a mixture; finally, the mixture is fed into a twin-screw extruder for extrusion and granulation. The die temperature of the twin-screw extruder is 250℃, the screw speed is 150 r / min, and the temperatures of each section are controlled at 220℃ for the first section, 240℃ for the second section, 250℃ for the third section, and 245℃ for the fourth section, respectively, to obtain a graphene content of 15%. wt % of graphene masterbatch.

[0022] Comparative Example 2 A method for preparing a core-sheath fiber includes the following steps: First, according to the formula ratio, 20 parts of graphene masterbatch prepared in Comparative Example 1 are mixed with 80 parts of PET as the sheath material, and PET is used as the core material. Then, 30 parts of the sheath material and 70 parts of the core material are fed into the corresponding screws of a spinning machine for spinning. The spinning temperature is 280℃, the spinning speed is 2000 m / min, the spinning cooling air temperature is 25℃, and the spinning cooling air velocity is 1 m / s, thereby obtaining the core-sheath fiber.

[0023] Comparative Example 3 A method for preparing graphene masterbatch for core-sheath fibers includes the following steps: First, according to the formula ratio, 20 parts of graphene, 73 parts of 250-mesh PBT powder, and 7 parts of sodium dodecylbenzenesulfonate are added to a high-speed mixer and stirred at 700 r / min for 15 min at room temperature to obtain a mixture; finally, the mixture is fed into a twin-screw extruder for extrusion and granulation. The die temperature of the twin-screw extruder is 250℃, the screw speed is 200 r / min, and the temperatures of each section are controlled at 220℃ for the first section, 240℃ for the second section, 250℃ for the third section, and 245℃ for the fourth section, respectively, to obtain a graphene content of 20%. wt % of graphene masterbatch.

[0024] Comparative Example 4 A method for preparing a core-sheath fiber includes the following steps: First, according to the formula ratio, 20 parts of graphene masterbatch prepared in Comparative Example 3 are mixed with 80 parts of PET as the sheath material, and PET is used as the core material. Then, 30 parts of the sheath material and 70 parts of the core material are fed into the corresponding screws of a spinning machine for spinning. The spinning temperature is 280℃, the spinning speed is 2000 m / min, the spinning cooling air temperature is 25℃, and the spinning cooling air velocity is 1 m / s, thereby obtaining the core-sheath fiber.

[0025] Comparative Example 5 A method for preparing graphene masterbatch for core-sheath fibers includes the following steps: First, according to the formula ratio, 30 parts of graphene, 60 parts of 300-mesh PBT powder, and 10 parts of KH560 silane coupling agent are added to a high-speed mixer and stirred at 800 r / min for 25 min at room temperature to obtain a mixture; finally, the mixture is fed into a twin-screw extruder for extrusion and granulation. The die temperature of the twin-screw extruder is 250℃, the screw speed is 300 r / min, and the temperatures of each section are controlled at 220℃ for the first section, 240℃ for the second section, 250℃ for the third section, and 245℃ for the fourth section, respectively, to obtain a graphene content of 30%. wt % of graphene masterbatch.

[0026] Comparative Example 6 A method for preparing a core-sheath fiber includes the following steps: First, according to the formula ratio, 20 parts of graphene masterbatch prepared in Comparative Example 5 are mixed with 80 parts of PET as the sheath material, and PET is used as the core material. Then, 30 parts of the sheath material and 70 parts of the core material are fed into the corresponding screws of a spinning machine for spinning. The spinning temperature is 280℃, the spinning speed is 2000 m / min, the spinning cooling air temperature is 25℃, and the spinning cooling air velocity is 1 m / s, thereby obtaining the core-sheath fiber.

[0027] In the above embodiments and comparative examples, PBT (polybutylene terephthalate) was purchased from BSF GmbH, Germany; GMA was purchased from Sumitomo Chemical Co., Ltd., Japan; DCP was purchased from Jiangsu Daoming Chemical Co., Ltd.; antioxidants were purchased from BSF GmbH, Germany; graphene was purchased from Changzhou Sixth Element Materials Technology Co., Ltd.; PET was purchased from BSF GmbH, Germany; polypyrrolidone was purchased from BSF GmbH, Germany; sodium dodecylbenzenesulfonate was purchased from Nanjing Jiaji New Materials Technology Co., Ltd.; and KH560 was purchased from Jiangxi Chenxin New Materials Technology Co., Ltd.

[0028] Performance testing: 1. Testing method: The properties of the core-sheath fibers prepared in Example 3, Comparative Example 2, Comparative Example 4, and Comparative Example 6 were tested using the following methods: Thermal conductivity test: The hot wire method was used, and the test was conducted in accordance with GB / T 3399-1982 "Test Method for Thermal Conductivity of Plastics - Hot Plate Method". Tensile strength test: The test was conducted using an electronic single yarn tensile tester in accordance with GB / T 14344-2008 "Test Method for Tensile Properties of Chemical Fiber Filaments" at a tensile speed of 300 mm / min. Broken yarn rate statistics: During the spinning process, the number of broken yarns per hour is recorded, and the average value is taken as the broken yarn rate after 8 consecutive hours.

[0029] 2. Test Results: Table 1. Performance data of core-sheath fibers prepared in each embodiment and comparative example.

[0030] As can be seen from the test results in Table 1, the core-sheath fiber prepared by graphene / PBT masterbatch in Example 3 has a thermal conductivity of up to 2.3 W / (m•K), a breaking strength of up to 4 cN / dtex, and a fiber breakage rate of 0.5 times / hour, which is superior to the corresponding properties of the core-sheath fiber prepared by other comparative examples (the difference being the use of other different dispersants).

[0031] The above embodiments are not intended to limit the product form and style of the present invention. Any appropriate changes or modifications made by those skilled in the art should be considered as not departing from the patent scope of the present invention.

Claims

1. A method for preparing graphene / PBT masterbatch for core-sheath fibers, characterized in that: Includes the following steps: Step 1: First, according to the formula ratio, add 100 parts PBT, 1~5 parts GMA, 0.1~0.5 parts DCP and 0.2~0.5 parts antioxidant into a high-speed mixer and stir at room temperature to obtain mixture A; Step 2: Then, the mixture A is fed into a twin-screw extruder for grafting, extrusion, and granulation. The temperature of each section of the twin-screw extruder is controlled at 180~200℃ in the first section, 230~250℃ in the second section, 220~230℃ in the third section, and 220~230℃ in the fourth section. After water-cooled stringing and pelletizing, PBT-g-GMA is obtained. Step 3: Then, according to the formula ratio, add 10-30 parts of graphene, 60-85 parts of PBT powder and 5-10 parts of PBT-g-GMA into a high-speed mixer and stir at room temperature to obtain mixture B. Step 4: Finally, mixture B is fed into a twin-screw extruder for extrusion and granulation. The temperatures of each section of the twin-screw extruder are controlled at 220-230℃ in the first section, 230-240℃ in the second section, 240-250℃ in the third section, and 245-255℃ in the fourth section, respectively, to obtain a graphene content of 10%. wt %~30 wt % of graphene / PBT masterbatch.

2. The method for preparing graphene / PBT masterbatch for core-sheath fibers according to claim 1, characterized in that: In step 1, the stirring speed is 50~60 r / min, and the stirring time is 5~10 min.

3. The method for preparing graphene / PBT masterbatch for core-sheath fibers according to claim 1, characterized in that: In step 1, the antioxidant is antioxidant 1010 or antioxidant 1076.

4. The method for preparing graphene / PBT masterbatch for core-sheath fibers according to claim 1, characterized in that: In step 2, the die head temperature of the twin-screw extruder is 200~220℃, and the screw speed is 200~300 r / min.

5. The method for preparing graphene / PBT masterbatch for core-sheath fibers according to claim 1, characterized in that: In steps 1 and 3, the particle size of the PBT powder is 200-300 mesh.

6. The method for preparing graphene / PBT masterbatch for core-sheath fibers according to claim 1, characterized in that: In step 3, the stirring speed is 500~1000 r / min, and the stirring time is 10~30 min.

7. The method for preparing graphene / PBT masterbatch for core-sheath fibers according to claim 1, characterized in that: In step 4, the die head temperature of the twin-screw extruder is 250~260℃, and the screw speed is 100~300 r / min.

8. A method for preparing core-sheath fibers, characterized in that: Includes the following steps: First, according to the formula ratio, 10-30 parts of graphene / PBT masterbatch as described in claim 1 are mixed with 70-90 parts of PET as the sheath material, and PET is used as the core material. Then, 20-40 parts of the sheath material and 60-80 parts of the core material are fed into the corresponding screws of the spinning machine for spinning to obtain the sheath-core fiber.

9. The method for preparing a core-sheath fiber according to claim 8, characterized in that: The spinning temperature is 270~290℃, the spinning speed is 1000~3000 m / min, the cooling air temperature is 20~30℃, and the cooling air velocity is 0.5~2 m / s.

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