Preparation method and application of polyester fiber composite thermal insulation material

Abstract

This invention discloses a method for preparing and applying a polyester fiber composite thermal insulation material, belonging to the technical field of polyester fiber materials. The invention involves mixing porous particles with modified PET (melt-grafted with maleic anhydride and glycidyl methacrylate), POE, and an initiator to prepare a low-melting-point blended granule. Using the low-melting-point blended granule as the sheath material and polyester fiber PET as the core material, a sheath-core bicomponent filament is prepared, ultimately yielding a polyester fiber composite thermal insulation material. Regarding thermal conductivity, the addition of a mixture of silica nanospheres and halloysite nanotubes as porous particles creates a more complex pore structure, which is beneficial for improving thermal conductivity. Regarding compression set, by using modified PET as the sheath material and collaborating with porous particles, the compression set of the polyester fiber composite thermal insulation material can be improved. The product of this invention can be used as a composite cold-proof material for high-speed trains.

Description

Technical Field

[0001] This invention relates to the field of polyester fiber materials technology, specifically to a method for preparing and applying a polyester fiber composite thermal insulation material. Background Technology

[0002] Polyester fiber is a fiber spun from a fiber-forming polymer whose macromolecular chains are linked by ester groups. It primarily refers to fibers produced from polyethylene terephthalate (PET). Polyester fiber is produced through melt spinning. Generally, polyester resin chips are vacuum dried to remove adsorbed trace amounts of moisture, transforming the resin from an amorphous to a crystalline form. The melt is then heated under an inert gas atmosphere. A specific quantity of fibers is extruded through spinnerets under pressure, and after cooling, the fibers are formed.

[0003] Polyester fiber has many advantages, such as high tensile strength and elastic modulus, moderate resilience, excellent heat setting effect, and good heat and light resistance. Its melting point is approximately 255℃, and its glass transition temperature is about 70℃. It maintains shape stability under a wide range of application conditions, and fabrics made from it are washable and durable. Furthermore, polyester fiber exhibits excellent resistance to organic solvents, soap, detergents, bleach, and antioxidants, while also possessing good corrosion resistance and stability against weak acids and alkalis. Therefore, it is widely used in textile and apparel manufacturing, industry, agriculture, and high-tech fields. When selecting composite cold-weather protection materials for high-speed trains, polyester fiber's good wrinkle resistance and high strength are advantageous as a candidate material. However, polyester fiber also has drawbacks such as insufficient water repellency, excessive compression set, high thermal conductivity, and inadequate flame retardancy, requiring modification to further meet more stringent application requirements. Summary of the Invention

[0004] In view of the above-mentioned prior art, the purpose of this invention is to provide a method for preparing polyester fiber composite thermal insulation material and its application.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a method for preparing a polyester fiber composite thermal insulation material, comprising the following steps: (1) Preparation of modified PET: PET, maleic anhydride, glycidyl methacrylate, initiator and antioxidant are mixed and melt-extruded under vacuum to obtain modified PET; The initiator used was dicyclohexyl peroxide dicarbonate, and the antioxidant used was antioxidant 1010; (2) Preparation of low melting point blended granules: The modified PET, porous particles, POE and initiator obtained in step (1) are mixed and then heated and melted and extruded to obtain low melting point blended granules; The porous particles used include at least one of silica nanospheres or halloysite nanotubes; the initiator used is di-tert-butyl peroxide; (3) The low melting point blended granules obtained in step (2) are used as the skin layer raw material and PET is used as the core layer raw material. After spunbonding, polyester fiber composite thermal insulation material is finally obtained.

[0006] Furthermore, in step (1), the mass ratio of PET, maleic anhydride, glycidyl methacrylate, dicyclohexyl peroxide, and antioxidant 1010 is (90-110):(0.5-5):(0.5-5):(0.01-1):(0.1-1).

[0007] Furthermore, in step (1), the melt extrusion temperature is 260-270℃.

[0008] Furthermore, in step (2), the mass ratio of modified PET, porous particles, POE, and di-tert-butyl peroxide is (80-90):(5-10):(5-10):(0.1-1).

[0009] Furthermore, in step (2), the mass ratio of silica nanospheres to halloysite nanotubes is (1-2):(1-2).

[0010] Furthermore, in step (2), the heating and melting temperature is 190-210℃.

[0011] Furthermore, in step (3), the mass ratio of the cortex material to the core material is (2-8):(2-8).

[0012] Furthermore, in step (3), after spunbond treatment, a water-repellent agent and a flame retardant are sprayed on.

[0013] In a second aspect, the present invention provides a polyester fiber composite thermal insulation material obtained by the preparation method described above.

[0014] A third aspect of the present invention provides the application of the aforementioned polyester fiber composite insulation material in the preparation of composite cold-proof materials for high-speed trains.

[0015] The beneficial effects of this invention are: This invention uses a mixture of silica nanospheres and halloysite nanotubes as porous particles, which are then mixed with modified PET (melt-grafted with maleic anhydride and glycidyl methacrylate), POE, and an initiator to prepare low-melting-point blended granules. Using these low-melting-point blended granules as the sheath material and polyester fiber PET as the core material, a sheath-core bicomponent filament is prepared, ultimately yielding a polyester fiber composite insulation material. Regarding thermal conductivity, the addition of porous particles is beneficial for improving thermal conductivity; the mixture of silica nanospheres and halloysite nanotubes, when added as porous particles, forms a more complex pore structure, which is beneficial for improving thermal conductivity. Regarding compression set, by using modified PET as the sheath material and collaborating with porous particles, the compression set of the polyester fiber composite insulation material can be improved. Detailed Implementation

[0016] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0017] To enable those skilled in the art to better understand the technical solution of this application, the technical solution of this application will be described in detail below with reference to specific embodiments.

[0018] Unless otherwise specified, all experimental materials used in the embodiments of this invention are conventional experimental materials in the art and can be purchased commercially. The silica nanospheres used in this invention have an average particle size of approximately 50±10 nm and a pore volume greater than 0.5 cm³. 3 The following materials were purchased: / g, magnetic mesoporous silica nanoparticles 50nm (item number), from Shaanxi Xingbei Aike Biotechnology Co., Ltd.; Halloysite nanotubes, hollow tubular in shape, with an inner diameter of 20±10nm, an outer diameter of 60±10nm, and a length of 0.6±0.3μm, from Guangdong Jina New Materials Technology Co., Ltd. (item number JN-1); di-tert-butyl peroxide (CAS number 110-05-4); POE (ENGAGE 7467 from Dow Chemical); antioxidant 1010 (CAS number 6683-19-8); hydrophobic agent SILRES BS 1001 (organosilicon hydrophobic agent), from Wacker Chemie AG (Germany); and flame retardant T100 (environmentally friendly flame retardant for coatings), from Jiangsu Younuode New Materials Co., Ltd.

[0019] Example 1: Preparation of Polyester Fiber Composite Thermal Insulation Material (1) Preparation of modified PET: 100g of PET chips, 1g of maleic anhydride (MAH), 1g of glycidyl methacrylate (GMA), 0.1g of dicyclohexyl peroxide (DCP) as an initiator and 0.2g of antioxidant 1010 were mixed and then melt-grafted at 265°C under vacuum to obtain modified PET.

[0020] (2) Preparation of low melting point blended granules: 85g of modified PET, 8g of porous granules, 6.85g of POE and 0.15g of initiator di-tert-butyl peroxide were mixed and then heated to 200℃ for melt extrusion granulation to obtain low melting point blended granules.

[0021] The porous particles used are a mixture of silica nanospheres and halloysite nanotubes, wherein the mass ratio of silica nanospheres to halloysite nanotubes is 1:1.

[0022] (3) Using low-melting-point blended granules as the sheath material and polyester fiber PET as the core material, the sheath material and core material were dried at 70℃ for 12h to achieve a moisture content of ≤40ppm. The dried sheath material was melt-extruded into a metering pump at 200℃ using a screw extruder, and the dried core material was melt-extruded at 220℃. The die temperature was controlled at 232℃, and the mass ratio of sheath material to core material was controlled at 40:60. Side-blown cooling was performed at a temperature of 25℃ and a pressure of 250Pa. The sheath-core bicomponent filament was drawn at a drawing pressure of 0.22MPa. The sheath-core bicomponent filament was then pre-shaped at 70℃, heat-cured at 125℃ and a linear pressure of 65N / mm, and then heat-set at 135℃ and a circulating air opening of 45% for 0.5h. When naturally cooled to 45℃, spray the water-repellent agent and flame retardant according to the specified ratio; dilute the water-repellent agent and flame retardant concentrates in water at a volume ratio of 1:10, and spray them on both sides according to the fiber material area at a total dosage of 6m² / L. Dry with cold air at 20℃ for 5 hours to obtain polyester fiber composite insulation material.

[0023] Example 2: Preparation of Polyester Fiber Composite Thermal Insulation Material (1) Preparation of modified PET: 100g of PET chips, 1g of maleic anhydride (MAH), 1g of glycidyl methacrylate (GMA), 0.1g of dicyclohexyl peroxide (DCP) as an initiator and 0.2g of antioxidant 1010 were mixed and then melt-grafted at 265°C under vacuum to obtain modified PET.

[0024] (2) Preparation of low melting point blended granules: 85g of modified PET, 8g of porous granules, 6.85g of POE and 0.15g of initiator di-tert-butyl peroxide were mixed and then heated to 200℃ for melt extrusion granulation to obtain low melting point blended granules.

[0025] The porous particles used are a mixture of silica nanospheres and halloysite nanotubes, wherein the mass ratio of silica nanospheres to halloysite nanotubes is 1:2.

[0026] (3) Using low-melting-point blended granules as the sheath material and polyester fiber PET as the core material, the sheath material and core material were dried at 70℃ for 12h to achieve a moisture content of ≤40ppm. The dried sheath material was melt-extruded into a metering pump at 200℃ using a screw extruder, and the dried core material was melt-extruded at 220℃. The die temperature was controlled at 232℃, and the mass ratio of sheath material to core material was controlled at 40:60. Side-blown cooling was performed at a temperature of 25℃ and a pressure of 250Pa. The sheath-core bicomponent filament was drawn at a drawing pressure of 0.22MPa. The sheath-core bicomponent filament was then pre-shaped at 70℃, heat-cured at 125℃ and a linear pressure of 65N / mm, and then heat-set at 135℃ and a circulating air opening of 45% for 0.5h. When naturally cooled to 45℃, spray the water-repellent agent and flame retardant according to the specified ratio; dilute the water-repellent agent and flame retardant concentrates in water at a volume ratio of 1:10, and spray them on both sides according to the fiber material area at a total dosage of 6m² / L. Dry with cold air at 20℃ for 5 hours to obtain polyester fiber composite insulation material.

[0027] Example 3: Preparation of Polyester Fiber Composite Thermal Insulation Material (1) Preparation of modified PET: 100g of PET chips, 1g of maleic anhydride (MAH), 1g of glycidyl methacrylate (GMA), 0.1g of dicyclohexyl peroxide (DCP) as an initiator and 0.2g of antioxidant 1010 were mixed and then melt-grafted at 265°C under vacuum to obtain modified PET.

[0028] (2) Preparation of low melting point blended granules: 85g of modified PET, 8g of porous granules, 6.85g of POE and 0.15g of initiator di-tert-butyl peroxide were mixed and then heated to 200℃ for melt extrusion granulation to obtain low melting point blended granules.

[0029] The porous particles used are a mixture of silica nanospheres and halloysite nanotubes, wherein the mass ratio of silica nanospheres to halloysite nanotubes is 2:1.

[0030] (3) Using low-melting-point blended granules as the sheath material and polyester fiber PET as the core material, the sheath material and core material were dried at 70℃ for 12h to achieve a moisture content of ≤40ppm. The dried sheath material was melt-extruded into a metering pump at 200℃ using a screw extruder, and the dried core material was melt-extruded at 220℃. The die temperature was controlled at 232℃, and the mass ratio of sheath material to core material was controlled at 40:60. Side-blown cooling was performed at a temperature of 25℃ and a pressure of 250Pa. The sheath-core bicomponent filament was drawn at a drawing pressure of 0.22MPa. The sheath-core bicomponent filament was then pre-shaped at 70℃, heat-cured at 125℃ and a linear pressure of 65N / mm, and then heat-set at 135℃ and a circulating air opening of 45% for 0.5h. When naturally cooled to 45℃, spray the water-repellent agent and flame retardant according to the specified ratio; dilute the water-repellent agent and flame retardant concentrates in water at a volume ratio of 1:10, and spray them on both sides according to the fiber material area at a total dosage of 6m² / L. Dry with cold air at 20℃ for 5 hours to obtain polyester fiber composite insulation material.

[0031] Comparative Example 1 The difference between this comparative example and Example 1 is that, in step (2), the porous particles used are silica nanospheres. Finally, a polyester fiber insulation material is obtained.

[0032] Comparative Example 2 The difference between this comparative example and Example 1 is that, in step (2), the porous particles used are halloysite nanotubes. Finally, a polyester fiber insulation material is obtained.

[0033] Comparative Example 3 The difference between this comparative example and Example 1 is that porous particles are not used in step (2), as follows: Preparation of low-melting-point blended granules: 85g of modified PET, 6.85g of POE, and 0.15g of initiator di-tert-butyl peroxide were mixed and then melt-extruded and granulated at 200℃ to obtain low-melting-point blended granules. Finally, polyester fiber insulation material was obtained.

[0034] Comparative Example 4 The difference between this comparative example and Example 1 is that, in step (2), unmodified PET was used, as detailed below: Preparation of low-melting-point blended granules: 85g of unmodified PET, 6.85g of POE, and 0.15g of initiator di-tert-butyl peroxide were mixed and then melt-extruded and granulated at 200℃ to obtain low-melting-point blended granules. Finally, polyester fiber insulation material was obtained.

[0035] Comparative Example 5 The difference between this comparative example and Example 1 is that in step (3), only polyester fiber PET is used as the raw material to prepare the thermal insulation material, as follows: Polyester fiber (PET) was dried at 70℃ for 12 hours to achieve a moisture content ≤40ppm. The dried raw material was then melt-extruded using a screw extruder at 220℃, with the die temperature controlled at 232℃. Side-blown cooling was performed at a temperature of 25℃ and a pressure of 250Pa, followed by drawing to obtain filaments at a drawing pressure of 0.22MPa. The filaments were then pre-shaped at 70℃, heat-cured at 125℃ and a linear pressure of 65N / mm, and then heat-set at 135℃ with a circulating air opening of 45% for 0.5 hours. After natural cooling to 45℃, a water-repellent agent and a flame retardant were sprayed according to a specific ratio. The water-repellent agent and flame retardant concentrates were diluted in water at a volume ratio of 1:10, and then sprayed on both sides at a total dosage of 6m² / L based on the fiber material area. The mixture was then dried with cold air at 20℃ for 5 hours to obtain the polyester fiber composite insulation material.

[0036] Experimental Example 1 The final thermal insulation materials obtained in Examples 1-3 and Comparative Examples 1-5 were tested for water repellency, compression set, thermal conductivity, and flame retardancy. The test methods are as follows: (1) Hydrophobicity Perform the test according to the provisions of "GB / T 10299-2011 Test Method for Hydrophobicity of Thermal Insulation Materials".

[0037] (2) Compression permanent deformation Perform the test according to GB / T6669-2008, with a compression rate of 50% and a placement at 23℃ for 72 hours.

[0038] (3) Thermal conductivity The thermal conductivity at -40℃ was tested using the method specified in "GB / T 10295-2008 Determination of Steady-State Thermal Resistance and Related Properties of Insulation Materials - Heat Flow Meter Method".

[0039] (4) Flame retardant properties The test shall be conducted in accordance with the provisions of "GB 8410-2006 Combustion Characteristics of Automotive Interior Materials" and using the horizontal combustion method.

[0040] The results are shown in Table 1.

[0041] Table 1 Test Results As shown in Table 1, Example 1 exhibits the best performance in terms of hydrophobicity, compression set, thermal conductivity, and flame retardancy. Regarding thermal conductivity, Examples 1 and Comparative Example 4 are superior to Comparative Examples 1-3, indicating that the addition of porous particles is beneficial for improving thermal conductivity. The mixture of silica nanospheres and halloysite nanotubes, added as porous particles, forms a more complex porous structure, which is beneficial for improving thermal conductivity. In terms of compression set, Comparative Examples 3-5 are worse than Example 1, indicating that using modified PET as the skin layer material and collaborating with porous particles can improve the compression set of the polyester fiber composite insulation material.

[0042] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for preparing a polyester fiber composite thermal insulation material, characterized in that, Includes the following steps: (1) Preparation of modified PET: PET, maleic anhydride, glycidyl methacrylate, initiator and antioxidant are mixed and melt-extruded under vacuum to obtain modified PET; The initiator used was dicyclohexyl peroxide dicarbonate, and the antioxidant used was antioxidant 1010; (2) Preparation of low melting point blended granules: The modified PET, porous particles, POE and initiator obtained in step (1) are mixed and then heated and melted and extruded to obtain low melting point blended granules; The porous particles used include at least one of silica nanospheres or halloysite nanotubes; the initiator used is di-tert-butyl peroxide; (3) The low melting point blended granules obtained in step (2) are used as the skin layer raw material and PET is used as the core layer raw material. After spunbonding, polyester fiber composite thermal insulation material is finally obtained.

2. The method for preparing the polyester fiber composite thermal insulation material according to claim 1, characterized in that, In step (1), the mass ratio of PET, maleic anhydride, glycidyl methacrylate, dicyclohexyl peroxide, and antioxidant 1010 is (90-110):(0.5-5):(0.5-5):(0.01-1):(0.1-1).

3. The method for preparing the polyester fiber composite thermal insulation material according to claim 1, characterized in that, In step (1), the melt extrusion temperature is 260-270℃.

4. The method for preparing the polyester fiber composite thermal insulation material according to claim 1, characterized in that, In step (2), the mass ratio of modified PET, porous particles, POE, and di-tert-butyl peroxide is (80-90):(5-10):(5-10):(0.1-1).

5. The method for preparing the polyester fiber composite thermal insulation material according to claim 1, characterized in that, In step (2), the mass ratio of silica nanospheres to halloysite nanotubes is (1-2):(1-2).

6. The method for preparing the polyester fiber composite thermal insulation material according to claim 1, characterized in that, In step (2), the heating and melting temperature is 190-210℃.

7. The method for preparing the polyester fiber composite thermal insulation material according to claim 1, characterized in that, In step (3), the mass ratio of the cortex material to the core material is (2-8):(2-8).

8. The method for preparing the polyester fiber composite thermal insulation material according to claim 1, characterized in that, In step (3), after spunbond treatment, a water-repellent agent and a flame retardant are sprayed on.

9. The polyester fiber composite thermal insulation material obtained by the preparation method according to any one of claims 1-8.

10. The application of the polyester fiber composite thermal insulation material according to claim 9 in the preparation of composite cold-proof materials for high-speed trains.

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