Preparation method and application of solid-solid phase change fiber with flame retardance and / or photo-thermal performance
Solid-solid phase change fibers with flame retardant and/or photothermal properties were prepared by chemical crosslinking and wet spinning, solving the problems of leakage and flammability of phase change materials, and realizing the weavability and multifunctional thermal management of phase change fibers.
Patent Information
- Application Number
- CN202511280053.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-09
- Publication Date
- 2025-12-02
AI Technical Summary
Existing solid-liquid phase change materials have leakage problems during transportation, storage and use. Traditional organic phase change materials are flammable and do not have weavability. Existing phase change fibers have limited functions and cannot achieve all-weather, all-season thermal management.
Solid-solid phase change fibers with flame-retardant and/or photothermal properties are prepared by crosslinking polyethylene glycol with isocyanate solution under a catalyst, adding flame retardants and/or photothermal agents, and then wet spinning and drying.
The prepared phase change fibers have shape stability and weavability, can absorb and release heat energy at constant temperature, and have excellent enthalpy and flame retardant properties, making them suitable for multifunctional fabrics such as fire-fighting equipment.
Smart Images
Figure CN121046972A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of thermal storage and temperature regulation phase change materials, and particularly relates to a method for preparing and applying a solid-solid phase change fiber with flame retardant and / or photothermal properties. Background Technology
[0002] The gradual depletion of fossil fuels globally has led to environmental pollution and the greenhouse effect. In recent years, thermal energy storage technology based on phase change materials (PCMs) has been considered one of the most promising approaches to reducing energy consumption and improving energy efficiency. Meanwhile, PCM fibers, developed by combining PCMs with fiber manufacturing technology, exhibit excellent temperature control and regulation capabilities, highlighting their potential for application in personal thermal management textiles under varying weather conditions. However, the commercial application of PCMs still faces two challenges: first, leakage issues during the transportation and storage of solid-liquid PCMs; and second, the high flammability of organic PCMs, which severely limits their application in fire-fighting equipment, aerospace, and wearable electronic devices. Therefore, designing a solid-solid composite PCM with shape stability and good mechanical properties is of great significance for optimizing thermal management and promoting environmental protection.
[0003] Furthermore, considering the application of organic phase change materials in fire-fighting equipment, a certain degree of flame retardancy is crucial, and intrinsically flame-retardant solid-solid phase change materials provide the best solution for this. For example, in their research "Intrinsic Flame Retardancy and Flexible Solid-Solid Phase Change Materials with Self-Healing and Recyclability," Bai et al. introduced flame retardants into polyethylene glycol-based polyurethane through chemical crosslinking, preparing intrinsically flame-retardant solid-solid phase change material sheets. These sheets possess both flame-retardant properties and thermal energy storage capacity, along with excellent mechanical properties and shape stability, demonstrating great potential in the field of thermal energy storage. However, the lack of weavability in these phase change sheets significantly limits their application range. In addition, in their research "Intrinsically Flexible Phase Change Fibers for Intelligent Thermal Regulation", Liu et al. prepared a series of inherently ultra-flexible phase change fibers based on solid-solid phase change materials through polycondensation and wet spinning processes. However, when the temperature exceeds the phase change range, solid-solid phase change materials cannot effectively store and release energy, are inefficient, and have limited functionality, making it impossible to achieve all-weather, all-season thermal management. The limitations on human thermal management are particularly evident in extreme environments. Summary of the Invention
[0004] The purpose of this invention is to provide a method for preparing solid-solid phase change fibers with flame retardant and / or photothermal properties and their applications. The solid-solid phase change fibers provided by this invention can solve the following problems: leakage and shape instability problems in existing solid-liquid phase change materials during transportation, storage and use; high flammability of traditional organic phase change materials; lack of weavability in most solid-solid phase change materials; and the single function of existing phase change fibers.
[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a method for preparing solid-solid phase change fibers with flame-retardant and / or photothermal properties, comprising the following steps: (1) Mix polyethylene glycol with an organic solvent, add isocyanate solution, and carry out cross-linking reaction under the catalysis of a catalyst to obtain a prepolymer solution; (2) Add flame retardant and / or photothermal agent to the prepolymer solution obtained in step (1) and continue the crosslinking reaction to obtain a crosslinking solution; (3) Add the chain extender to the crosslinking solution obtained in step (2), perform chain extension reaction, wet spin, add to coagulation bath, dry, and obtain solid-solid phase change fiber with flame retardant and / or photothermal properties.
[0006] Further, the molecular weight of the polyethylene glycol in step (1) is 2000~10000 Da; the mass-to-volume ratio of the polyethylene glycol to the organic solvent is 1~6 g:10 mL; the organic solvent is... N,N -Dimethylformamide, N,N -Dimethylacetamide, N One or more of methylpyrrolidone and dimethyl sulfoxide.
[0007] Further, in step (1), the isocyanate is dissolved in an organic solvent to form an isocyanate solution, wherein the isocyanate accounts for (15~25)% of the mass of polyethylene glycol; the isocyanate is one or more of isophorone diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, and hexamethylene diisocyanate; the mass ratio of the catalyst to polyethylene glycol is 2~18µg:1~6g; the catalyst is dibutyltin dilaurate, stannous octoate, di(dodecylthio)dibutyltin, triethylamine, N,N One or more of dimethylbenzylamine; the organic solvent is... N,N -Dimethylformamide, N,N -Dimethylacetamide, N One or more of methylpyrrolidone and dimethyl sulfoxide, wherein the mass-to-volume ratio of isocyanate to organic solvent is 3-4 g: 10 mL.
[0008] Further, in step (1), the temperature of the crosslinking reaction is 30~70℃, and the time of the crosslinking reaction is 4~9h. Further, the amount of catalyst added is 2~5 drops.
[0009] Further, in step (2), the flame retardant accounts for (7~15)% of the mass of polyethylene glycol; the flame retardant is one or more of tetrabromobisphenol A, brominated epoxy resin, decabromodiphenyl ethane, and brominated polystyrene; the photothermal agent accounts for (1~3)% of the mass of polyethylene glycol; the photothermal agent is one or more of 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 1-naphthol, and 2-naphthol, the crosslinking reaction temperature is 60~90℃, and the crosslinking reaction time is 2~8 h.
[0010] Furthermore, in step (2), when adding the flame retardant and photothermal agent, the flame retardant is added first, and after a crosslinking reaction at 60-90℃ for 3-5 hours, the photothermal agent is added, and a crosslinking reaction at 60-90℃ for 2-3 hours is carried out. The flame retardant and / or photothermal agent need to be dissolved in an organic solvent before being added. The organic solvent is... N,N -Dimethylformamide, N,N -Dimethylacetamide, N One or more of methylpyrrolidone and dimethyl sulfoxide, the mass-volume ratio of flame retardant to organic solvent is 1~3 g:10mL, and the mass-volume ratio of photothermal agent to organic solvent is 0.2~0.6 g:10mL.
[0011] Further, in step (3), the chain extender accounts for (0.5~3.5)% of the mass of polyethylene glycol; the chain extender is one or more of 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol; the chain extension reaction temperature is 75~85℃, and the chain extension reaction time is 1~2h; the coagulation bath temperature of the wet spinning is 55~65℃; the coagulation bath is water; the drying temperature is 40~50℃, and the drying time is 20~25h. The chain extender needs to be dissolved in an organic solvent before being added; the organic solvent is... N,N -Dimethylformamide, N,N -Dimethylacetamide, N One or more of methylpyrrolidone and dimethyl sulfoxide, wherein the mass-to-volume ratio of chain extender to organic solvent is 0.1~0.6 g:10 mL.
[0012] The above-described preparation method is a method for preparing solid-solid phase change fibers with flame retardant and / or photothermal properties.
[0013] The present invention also provides the application of the above-mentioned solid-solid phase change fibers with flame retardant and / or photothermal properties in the preparation of products with flame retardant and / or photothermal properties.
[0014] The present invention also provides the application of the above-mentioned solid-solid phase change fibers with flame retardant properties or with both flame retardant and photothermal properties in the preparation of fire-fighting equipment.
[0015] The beneficial effects of this invention compared to the prior art are as follows: This invention uses polyethylene glycol, isocyanate, flame retardant, photothermal agent, etc. as raw materials, and prepares a uniform spinning solution through chemical cross-linking to achieve the spinnability of phase change fibers, thus enabling them to be woven into various fabrics. Phase change fibers are prepared through wet spinning; by adding polyethylene glycol of different molecular weights during the preparation of the spinning solution, phase change fibers with different phase change temperatures can be obtained. Adding flame retardants yields phase change fibers with flame-retardant properties; simultaneously adding flame retardants and photothermal agents yields phase change fibers with both flame-retardant and photothermal functions (light absorption and heat generation). Environmentally friendly solid-solid phase change fiber production is achieved by using water as a coagulation bath. The phase change fibers obtained by this invention have enhanced mechanical properties and can be applied to multifunctional fabrics, such as fire-fighting equipment. They also possess excellent enthalpy values, meeting the 5A-grade phase change fiber standard (melting enthalpy ≥ 72.0 J / g, crystallization enthalpy ≥ 72.0 J / g), exhibiting good heat storage and temperature regulation effects, and solving the leakage problem of traditional organic materials.
[0016] The solid-solid phase change fiber provided by this invention is a fiber-type phase change material capable of absorbing and releasing a large amount of heat energy at a near-constant temperature. This solid-solid phase change fiber exhibits excellent adjustable phase change temperature. The phase change temperatures of the flame-retardant phase change fibers and flame-retardant and photothermal phase change fibers in Examples 1-6 are all between 0 and 50°C. Specifically, the flame-retardant solid-solid phase change fiber obtained in Example 1 has a melting enthalpy of 80 J / g, a crystallization enthalpy of 77 J / g, a melting temperature of 48.6°C, a crystallization temperature of 26.5°C, a tensile strength of 2.50 MPa, and an elongation at break of 458%. The flame-retardant and photothermal phase change fiber in Example 4 has a melting enthalpy of 70 J / g, a crystallization enthalpy of 71 J / g, a melting temperature of 48.1°C, a crystallization temperature of 24.1°C, a tensile strength of 4.44 MPa, and an elongation at break of 1125%, while also exhibiting significant shape stability and weavability. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.
[0018] Figure 1 This is a flowchart illustrating the preparation process of solid-solid phase change fibers with flame-retardant properties. Figure 2This is a flowchart illustrating the preparation process of solid-solid phase change fibers with flame retardant and photothermal properties. Figure 3 Comparison of the shape stability of PEG, flame-retardant solid-solid phase change materials, and flame-retardant and photothermal solid-solid phase change materials under heat treatment at different temperatures; Figure 4 For flame-retardant solid-solid phase change materials and flame-retardant and photothermal solid-solid phase change materials at 100mW / cm 2 The curve of temperature change over time under light intensity; Figure 5 Photos of knotted solid-solid phase change fibers and fabric displays; Figure 6 Differential scanning calorimetry curves for solid-solid phase change fibers; Figure 7 The stress-strain curve of solid-solid phase change fiber; Figure 8 Images of ordinary cotton fibers, flame-retardant solid-solid phase change fibers, and flame-retardant and photothermal solid-solid phase change fibers. Figure 9 Vertical combustion tests were conducted on ordinary cotton fibers and flame-retardant solid-solid phase change fibers, as well as flame-retardant and photothermal solid-solid phase change fibers. Detailed Implementation
[0019] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.
[0020] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.
[0021] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.
[0022] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.
[0023] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.
[0024] This invention provides a method for preparing solid-solid phase change fibers with flame-retardant and / or photothermal properties, comprising the following steps: (1) Mix polyethylene glycol with an organic solvent, add isocyanate solution, and carry out cross-linking reaction under the catalysis of a catalyst to obtain a prepolymer solution; (2) Add flame retardant and / or photothermal agent to the prepolymer solution obtained in step (1) and continue the crosslinking reaction to obtain a crosslinking solution; (3) Add the chain extender to the crosslinking solution obtained in step (2), perform chain extension reaction, wet spin, add to coagulation bath, dry, and obtain solid-solid phase change fiber with flame retardant and / or photothermal properties.
[0025] In this invention, the molecular weight of the polyethylene glycol in step (1) is preferably 2000~10000 Da, more preferably 4000~8000 Da; the mass-to-volume ratio of the polyethylene glycol to the organic solvent is preferably 1~6 g:10 mL, more preferably 3~5 g:10 mL; the organic solvent preferably includes N,N -Dimethylformamide, N,N -Dimethylacetamide, N One or more of methylpyrrolidone and dimethyl sulfoxide; the mixing temperature is preferably 60-70°C; the isocyanate accounts for 15-25% of the mass of polyethylene glycol, more preferably 15-22%; the isocyanate is preferably one or more of isophorone diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, and hexamethylene diisocyanate, more preferably one or more of isophorone diisocyanate, toluene diisocyanate, and diphenylmethane diisocyanate; the mass ratio of the catalyst to polyethylene glycol is preferably 2-18µg:1-6g, more preferably 5-10µg:3-5g, and even more preferably 7µg:4g; the catalyst is dibutyltin dilaurate, stannous octoate, di(dodecylthio)dibutyltin, triethylamine, N,N One or more of dimethylbenzylamine; the temperature of the crosslinking reaction is preferably 30~70℃, and the time of the crosslinking reaction is preferably 4~9h.
[0026] In this invention, the flame retardant in step (2) accounts for (7~15)% of the mass of polyethylene glycol, more preferably (7~11.5)%; the flame retardant is one or more of tetrabromobisphenol A, brominated epoxy resin, decabromodiphenyl ethane, and brominated polystyrene, more preferably one or more of tetrabromobisphenol A, brominated epoxy resin, and decabromodiphenyl ethane; the crosslinking reaction temperature of the flame retardant is preferably 60~90℃; and the crosslinking reaction time of the flame retardant is preferably 3~5h.
[0027] In this invention, the photothermal agent in step (2) accounts for (1~3)% of the mass of polyethylene glycol; the photothermal agent is one or more of 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 1-naphthol, and 2-naphthol, more preferably one or more of 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, and 1,7-dihydroxynaphthalene; the crosslinking temperature of the photothermal agent is preferably 60~90℃, more preferably 70~80℃; the crosslinking time of the photothermal agent is preferably 2~3h.
[0028] In this invention, the chain extender in step (3) accounts for (0.5~3.5)% of the mass of polyethylene glycol, more preferably (0.5~3.2)%; the chain extender is one or more of 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol; the chain extension reaction temperature is preferably 75~85℃; the chain extension reaction time is preferably 1~2h; the coagulation bath temperature of the wet spinning is preferably 50~65℃, more preferably 55~65℃; the wet spinning rate is preferably 20mL / h; the coagulation bath is water; the washing treatment is preferably performed before drying, the washing temperature is preferably 40~50℃, and the washing time is preferably 25~35min; the drying temperature is preferably 40~50℃; the drying time is preferably 20~25h.
[0029] The present invention also provides the application of the solid-solid phase change fiber with flame retardant and photothermal properties obtained by the preparation method in the preparation of products with flame retardant and photothermal properties.
[0030] The present invention also provides the application of the solid-solid phase change fiber with flame retardant properties prepared by the preparation method described above, and the solid-solid phase change fiber with flame retardant and photothermal properties prepared by the preparation method in the preparation of fire-fighting equipment.
[0031] Example 1 A method for preparing a solid-solid phase change fiber with flame-retardant properties, comprising the following steps: (1) Mix 20g of polyethylene glycol 6000 with 50mL N,N Mix dimethylformamide and heat at 65°C until homogeneous. Dissolve 4g of isophorone diisocyanate in 10mL of solution. N,N After adding dimethylformamide to the above mixture, stir rapidly for 10 minutes to mix evenly, then add 2-3 drops of dibutyltin dilaurate catalyst, and crosslink at 65°C for 8 hours to obtain the prepolymer solution. (2) Dissolve 1.5g of tetrabromobisphenol A in 10mL N,N - Dimethylformamide was added to the prepolymer solution obtained in step (1), and the crosslinking reaction was continued at 80°C for 4 hours to obtain a crosslinking solution; (3) Dissolve 0.6 g of 1,4-butanediol in 10 mL N,N Dimethylformamide was added to the secondary crosslinking solution obtained in step (2), and the chain extension reaction was carried out at 80°C for 2 hours to obtain a spinning solution. The resulting spinning solution was wet-spun at a feed rate of 20 mL / h, with a coagulation bath of 65°C water. After removal, the solution was washed with water at 45°C for 30 minutes and dried at 45°C for 24 hours to obtain a solid-solid phase change fiber with flame retardant properties and a diameter of approximately 630 μm. The total amount of the above organic solvents was 80 mL.
[0032] Example 2 A method for preparing a solid-solid phase change fiber with flame-retardant properties, comprising the following steps: (1) Mix 16g of polyethylene glycol 4000 with 50mL N,N Mix dimethylformamide and heat at 65°C until homogeneous. Dissolve 3.4 g of isophorone diisocyanate in 10 mL of solution. N,N Add dimethylformamide to the above mixture, stir rapidly for 10 minutes to mix evenly, add 2-3 drops of dibutyltin dilaurate catalyst, and crosslink at 65°C for 8 hours to obtain the prepolymer solution. (2) Dissolve 1.8g of tetrabromobisphenol A in 10mL N,N - Dimethylformamide was added to the prepolymer solution obtained in step (1), and the crosslinking reaction was continued at 80°C for 4 hours to obtain a crosslinking solution; (3) Dissolve 0.5g of 1,4-butanediol in 10mL N,N - Dimethylformamide was added to the secondary crosslinking solution obtained in step (2), and the chain extension reaction was carried out at 80°C for 1 h to obtain the spinning solution. The obtained spinning solution was wet spun at a feed rate of 20 mL / h. The coagulation bath was water at 65°C, and the solution was washed with water at 40°C for 35 min and dried at 45°C for 24 h to obtain solid-solid phase change fiber with flame retardant properties. The total amount of the above organic solvents was 80 mL.
[0033] Example 3 A method for preparing a solid-solid phase change fiber with flame-retardant properties, comprising the following steps: (1) Mix 24g of polyethylene glycol 8000 with 50mL N,NMix dimethylformamide and heat at 65°C until homogeneous. Dissolve 3.7 g of isophorone diisocyanate in 10 mL of solution. N,N Add dimethylformamide to the above mixture, stir rapidly for 10 minutes to mix evenly, add 2-3 drops of dibutyltin dilaurate catalyst, and crosslink at 65°C for 8 hours to obtain the prepolymer solution. (2) Dissolve 1.7g of tetrabromobisphenol A in 10mL N,N - Dimethylformamide was added to the prepolymer solution obtained in step (1), and the crosslinking reaction was continued at 80°C for 4 hours to obtain a crosslinking solution; (3) Dissolve 0.5g of 1,4-butanediol in 10mL N,N - Dimethylformamide was added to the secondary crosslinking solution obtained in step (2), and the chain extension reaction was carried out at 80°C for 1 h to obtain a spinning solution. The obtained spinning solution was wet spun at a feed rate of 20 mL / h, with a coagulation bath of 65°C water. After removal, it was washed with water at 50°C for 25 min and dried at 45°C for 24 h to obtain solid-solid phase change fiber with flame retardant properties. The total amount of the above organic solvents was 80 mL.
[0034] Example 4 A method for preparing a solid-solid phase change fiber with flame retardant and photothermal properties, comprising the following steps: (1) Mix 20g of polyethylene glycol 6000 with 50mL N,N Mix dimethylformamide and heat at 65°C until homogeneous. Dissolve 4g of isophorone diisocyanate in 10mL of solution. N,N Add dimethylformamide to the above mixture, stir rapidly for 10 minutes to mix evenly, add 2-3 drops of dibutyltin dilaurate catalyst, and crosslink at 65°C for 8 hours to obtain the prepolymer solution. (2) Dissolve 1.8g of tetrabromobisphenol A in 10mL N,N - Dimethylformamide was added to the prepolymer solution obtained in step (1), and the crosslinking reaction was continued at 80°C for 4 hours to obtain a crosslinking solution; (3) Dissolve 0.25g of 1,5-dihydroxynaphthalene in 10mL N,N - Dimethylformamide was added to the crosslinking solution obtained in step (2), and the solution was further crosslinked at 80°C for 2 hours to obtain a secondary crosslinking solution; (4) Dissolve 0.15 g of 1,4-butanediol in 10 mL N,N- Dimethylformamide was added to the secondary crosslinking solution obtained in step (3), and the chain extension reaction was carried out at 80°C for 1 h to obtain a spinning solution. The obtained spinning solution was wet spun at a feed rate of 20 mL / h, with a coagulation bath of 65°C water. After removal, it was washed with water at 40°C for 35 min and dried at 40°C for 25 h to obtain a solid-solid phase change fiber with flame retardant and photothermal properties with a diameter of approximately 575 μm. The total amount of the above organic solvents was 90 mL.
[0035] Example 5 A method for preparing a solid-solid phase change fiber with flame retardant and photothermal properties, comprising the following steps: (1) Mix 16g of polyethylene glycol 4000 with 50mL N,N Mix dimethylformamide and heat at 65°C until homogeneous. Dissolve 3.4 g of isophorone diisocyanate in 10 mL of solution. N,N Add dimethylformamide to the above mixture, stir rapidly for 10 minutes to mix evenly, add 2-3 drops of dibutyltin dilaurate catalyst, and crosslink at 65°C for 8 hours to obtain the prepolymer solution. (2) Dissolve 1.8g of tetrabromobisphenol A in 10mL N,N - Dimethylformamide was added to the prepolymer solution obtained in step (1), and the crosslinking reaction was continued at 70°C for 4 hours to obtain a crosslinking solution; (3) Dissolve 0.32g of 1,5-dihydroxynaphthalene in 10mL N,N - Dimethylformamide was added to the crosslinking solution obtained in step (2), and the solution was further crosslinked at 70°C for 2 hours to obtain a secondary crosslinking solution; (4) Dissolve 0.18 g of 1,4-butanediol in 10 mL N,N - Dimethylformamide was added to the secondary crosslinking solution obtained in step (3), and the chain extension reaction was carried out at 80°C for 1 h to obtain a spinning solution. The obtained spinning solution was wet spun at a feed rate of 20 mL / h, with a coagulation bath of 65°C water. After removal, it was washed with water at 50°C for 25 min and dried at 50°C for 20 h to obtain solid-solid phase change fibers with flame retardant and photothermal properties. The total amount of the above organic solvents was 90 mL.
[0036] Example 6 A method for preparing a solid-solid phase change fiber with flame retardant and photothermal properties, comprising the following steps: (1) Mix 24g of polyethylene glycol 8000 with 50mL N,N Mix dimethylformamide and heat at 65°C until homogeneous. Dissolve 3.7 g of isophorone diisocyanate in 10 mL of solution. N,N Add dimethylformamide to the above mixture, stir rapidly for 10 minutes to mix evenly, add 2-3 drops of dibutyltin dilaurate catalyst, and crosslink at 65°C for 8 hours to obtain the prepolymer solution. (2) Dissolve 1.7g of tetrabromobisphenol A in 10mL N,N - Dimethylformamide was added to the prepolymer solution obtained in step (1), and the crosslinking reaction was continued at 80°C for 4 hours to obtain a crosslinking solution; (3) Dissolve 0.24 g of 1,5-dihydroxynaphthalene in 10 mL N,N - Dimethylformamide was added to the crosslinking solution obtained in step (2), and the solution was further crosslinked at 80°C for 2 hours to obtain a secondary crosslinking solution; (4) Dissolve 0.13 g of 1,4-butanediol in 10 mL N,N - Dimethylformamide was added to the secondary crosslinking solution obtained in step (3), and the chain extension reaction was carried out at 80°C for 1 h to obtain a spinning solution. The obtained spinning solution was wet spun at a feed rate of 20 mL / h, with a coagulation bath of 65°C water. After removal, it was washed with water at 40°C for 35 min and dried at 40°C for 25 h to obtain solid-solid phase change fibers with flame retardant and photothermal properties. The total amount of the above organic solvents was 90 mL.
[0037] Example 7 A method for preparing a solid-solid phase change fiber with flame-retardant properties, comprising the following steps: (1) Mix 20g of polyethylene glycol 6000 with 50mL N,N Mix dimethylacetamide and dimethylacetamide thoroughly at 60°C. Dissolve 4g of toluene diisocyanate in 10mL of water. N,N - Dimethylacetamide was added to the above mixture and stirred rapidly for 10 minutes to mix evenly. Then, 2-3 drops of stannous octoate catalyst were added, and the crosslinking reaction was carried out at 30°C for 9 hours to obtain the prepolymer solution. (2) Dissolve 1.5g of brominated epoxy resin in 10mL N,N - Dimethylacetamide was added to the prepolymer solution obtained in step (1), and the crosslinking reaction was continued at 60°C for 5 hours to obtain a crosslinking solution; (3) Dissolve 0.6 g of 1,4-butanediol in 10 mL N,N - Dimethylacetamide was added to the secondary crosslinking solution obtained in step (2), and the chain extension reaction was carried out at 75°C for 2 hours to obtain a spinning solution. The resulting spinning solution was wet-spun at a feed rate of 20 mL / h, with a coagulation bath of 55°C water. After removal, it was washed with water at 40°C for 35 minutes and dried at 40°C for 24 hours to obtain solid-solid phase change fibers with flame retardant properties. The total amount of the above organic solvents was 80 mL.
[0038] Example 8 A method for preparing a solid-solid phase change fiber with flame-retardant properties, comprising the following steps: (1) Mix 20g of polyethylene glycol 6000 with 50mL NMix methylpyrrolidone and homogenize at 70°C. Dissolve 4g of diphenylmethane diisocyanate in 10mL of water. N After adding methylpyrrolidone to the above mixture, stir rapidly for 10 minutes to mix evenly, then add 2-3 drops of di(dodecyl sulfide)dibutyltin catalyst, and crosslink at 70°C for 4 hours to obtain the prepolymer solution. (2) Dissolve 1.5g of decabromodiphenyl ethane in 10mL N After adding -methylpyrrolidone to the prepolymer solution obtained in step (1), the crosslinking reaction was continued at 90°C for 3 hours to obtain the crosslinking solution; (3) Dissolve 0.6 g of 1,4-butanediol in 10 mL N After adding methylpyrrolidone to the secondary crosslinking solution obtained in step (2), the chain extension reaction was carried out at 85°C for 1 h to obtain the spinning solution. The obtained spinning solution was wet spun at a feed rate of 20 mL / h, with the coagulation bath being water at 65°C. After removal, it was washed with water at 50°C for 25 min and dried at 50°C for 20 h to obtain solid-solid phase change fiber with flame retardant properties. The total amount of the above organic solvents was 80 mL.
[0039] Example 9 A method for preparing a solid-solid phase change fiber with flame retardant and photothermal properties, comprising the following steps: (1) Mix 20g of polyethylene glycol 6000 with 50mL N,N Mix dimethylacetamide and dimethylacetamide thoroughly at 60°C. Dissolve 4g of toluene diisocyanate in 10mL of water. N,N Add dimethylformamide to the above mixture, stir rapidly for 10 minutes to mix evenly, add 2-3 drops of stannous octoate catalyst, and crosslink at 30°C for 9 hours to obtain the prepolymer solution. (2) Dissolve 1.8g of brominated epoxy resin in 10mL N,N - Dimethylacetamide was added to the prepolymer solution obtained in step (1), and the crosslinking reaction was continued at 60°C for 5 hours to obtain a crosslinking solution; (3) Dissolve 0.25g of 1,6-dihydroxynaphthalene in 10mL N,N - Dimethylacetamide was added to the crosslinking solution obtained in step (2), and the solution was further crosslinked at 60°C for 3 hours to obtain a secondary crosslinking solution; (4) Add 0.15 g of 1,6-hexanediol to 10 mL N,N - Dimethylacetamide was added to the secondary crosslinking solution obtained in step (3), and the chain extension reaction was carried out at 75°C for 2 hours to obtain a spinning solution. The obtained spinning solution was wet spun at a feed rate of 20 mL / h, with a coagulation bath of 55°C water. After removal, it was washed with water at 40°C for 35 minutes and dried at 40°C for 25 hours to obtain solid-solid phase change fibers with flame retardant and photothermal properties. The total amount of the above organic solvents was 90 mL.
[0040] Example 10 A method for preparing a solid-solid phase change fiber with flame retardant and photothermal properties, comprising the following steps: (1) Mix 20g of polyethylene glycol 6000 with 50mL N Mix methylpyrrolidone and homogenize at 70°C. Dissolve 4g of diphenylmethane diisocyanate in 10mL of water. N After adding methylpyrrolidone to the above mixture, stir rapidly for 10 minutes to mix evenly, add 2-3 drops of di(dodecylthio)dibutyltin catalyst, and crosslink at 70°C for 4 hours to obtain the prepolymer solution. (2) Dissolve 1.8g of decabromodiphenyl ethane in 10mL N After adding -methylpyrrolidone to the prepolymer solution obtained in step (1), the crosslinking reaction was continued at 90°C for 3 hours to obtain the crosslinking solution; (3) Dissolve 0.25g of 1,7-dihydroxynaphthalene in 10mL N After adding -methylpyrrolidone to the crosslinking solution obtained in step (2), further crosslinking is carried out at 90°C for 2 hours to obtain a secondary crosslinking solution; (4) Dissolve 0.15 g of 1,6-hexanediol in 10 mL N After adding methylpyrrolidone to the secondary crosslinking solution obtained in step (3), the chain extension reaction was carried out at 85°C for 1 h to obtain the spinning solution. The obtained spinning solution was wet spun at a feed rate of 20 mL / h, with the coagulation bath being water at 65°C. After removal, it was washed with water at 50°C for 25 min and dried at 50°C for 20 h to obtain solid-solid phase change fibers with flame retardant and photothermal properties. The total amount of the above organic solvents was 90 mL.
[0041] Example 11 A method for preparing a solid-solid phase change fiber with photothermal properties, comprising the following steps: (1) Mix 20g of polyethylene glycol 6000 with 50mL of N,N-dimethylformamide and mix evenly at 65℃. Dissolve 4g of isophorone diisocyanate in 10mL of N,N-dimethylformamide and add it to the above mixture. Stir quickly for 10min to mix evenly. Add 2~3 drops of dibutyltin dilaurate catalyst and crosslink at 65℃ for 8h to obtain a prepolymer solution. (2) Dissolve 0.53g of 1,5-dihydroxynaphthalene in 10mL of N,N-dimethylformamide and add it to the prepolymer solution obtained in step (1). Continue the crosslinking reaction at 80 °C for 3h to obtain the crosslinking solution. (3) Dissolve 0.4 g of 1,4-butanediol in 10 mL of N,N-dimethylformamide and add it to the secondary crosslinking solution obtained in step (2). Perform chain extension reaction at 80 °C for 2 h to obtain spinning solution. Perform wet spinning of the obtained spinning solution at a feed rate of 20 mL / h. Use water at 65 °C for the coagulation bath. Remove the solution, wash with water at 45 °C for 30 min, and dry at 45 °C for 24 h to obtain solid-solid phase change fiber with photothermal properties. The total amount of the above organic solvents is 80 mL.
[0042] Experimental Example 1 The flame-retardant solid-solid phase change material prepared in Example 1 and the flame-retardant and photothermal solid-solid phase change material prepared in Example 4 were placed on a hot plate at 80°C for leak prevention testing. The results are as follows: Figure 3 As shown.
[0043] The results showed that, compared with PEG, the flame-retardant solid-solid phase change material prepared in Example 1 and the flame-retardant and photothermal solid-solid phase change material prepared in Example 4 maintained shape stability after being heated to 80°C for 1 hour and had excellent anti-leakage performance. In contrast, polyethylene glycol (PEG) exhibited typical solid-liquid phase change material characteristics and became liquid in a short time.
[0044] Experimental Example 2 Using xenon lamps to simulate sunlight (100mW / cm²) 2 The light absorption and heat dissipation properties of the flame-retardant solid-solid phase change fiber prepared in Example 1 and the flame-retardant and photothermal solid-solid phase change fiber prepared in Example 4 were tested under illumination. The results are as follows: Figure 4 As shown.
[0045] The results show that, under the same light intensity and time, the flame-retardant solid-solid phase change fiber obtained in Example 1 has a temperature that rises to about 41°C under light, while the flame-retardant and photothermal solid-solid phase change fiber obtained in Example 4 has a temperature that rises to about 72°C. The flame-retardant and photothermal solid-solid phase change fiber has good light absorption and heat generation capabilities.
[0046] Experimental Example 3 The flame-retardant solid-solid phase change fibers prepared in Example 1 and the flame-retardant and photothermal solid-solid phase change fibers prepared in Example 4 were knotted and woven. The results are as follows: Figure 5 As shown.
[0047] The results showed that the flame-retardant solid-solid phase change fiber prepared in Example 1 and the flame-retardant and photothermal solid-solid phase change fiber prepared in Example 4 had good flexibility and weavability.
[0048] Test Example 4 The phase transition characteristics of the flame-retardant solid-solid phase change fiber prepared in Example 1 and the flame-retardant and photothermal solid-solid phase change fiber prepared in Example 4 were determined using differential scanning calorimetry (DSC), and the corresponding DSC curves were plotted. Simultaneously, the mechanical properties of the flame-retardant solid-solid phase change fiber prepared in Example 1 and the flame-retardant and photothermal solid-solid phase change fiber prepared in Example 4 were determined using a universal testing machine, and stress-strain curves were plotted. The results are as follows: Figure 6 and Figure 7 As shown.
[0049] The results showed that the flame-retardant solid-solid phase change fiber prepared in Example 1 had a melting enthalpy of 80 J / g, a crystallization enthalpy of 77 J / g, a melting temperature of 48.6℃, a crystallization temperature of 26.5℃, a tensile strength of 2.50 MPa, and an elongation at break of 458%; the flame-retardant and photothermal solid-solid phase change fiber prepared in Example 4 had a melting enthalpy of 70 J / g, a crystallization enthalpy of 71 J / g, a melting temperature of 48.1℃, a crystallization temperature of 24.1℃, a tensile strength of 4.44 MPa, and an elongation at break of 1125%.
[0050] Experimental Example 5 Vertical burning tests were conducted on ordinary cotton fiber (purchased from http: / / item.taobao.com / item.htm?id=709043730519), the flame-retardant solid-solid phase change fiber prepared in Example 1, and the flame-retardant and photothermal solid-solid phase change fiber prepared in Example 4. The results are as follows: Figure 8 and Figure 9 As shown.
[0051] The results showed that when ordinary cotton thread was ignited by an alcohol lamp, the flame continued to burn along the length of the cotton thread. In contrast, the flame-retardant solid-solid phase change fiber prepared in Example 1 and the flame-retardant and photothermal solid-solid phase change fiber prepared in Example 4 exhibited excellent self-extinguishing properties. After being directly exposed to a flame, the fiber would briefly ignite, but once the flame source was removed, the fiber would quickly self-extinguish, indicating that the flame retardancy was significantly improved.
[0052] As can be seen from the above embodiments, the present invention provides a method for preparing solid-solid phase change fibers with flame retardant and / or photothermal properties and their application. The solid-solid phase change fibers are linear and have the characteristics of no leakage, high heat storage density, good thermal cycling performance, and excellent elongation at break. Moreover, the diameter can be adjusted, making them very suitable for multifunctional fabrics.
[0053] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A method for preparing and applying a solid-solid phase change fiber with flame-retardant and / or photothermal properties, characterized in that, Includes the following steps: (1) Mix polyethylene glycol with an organic solvent, add isocyanate solution, and carry out cross-linking reaction under the catalysis of a catalyst to obtain a prepolymer solution; (2) Add flame retardant and / or photothermal agent to the prepolymer solution obtained in step (1) and continue the crosslinking reaction to obtain a crosslinking solution; (3) Add the chain extender to the crosslinking solution obtained in step (2), perform chain extension reaction, wet spin, add to coagulation bath, dry, and obtain solid-solid phase change fiber with flame retardant and / or photothermal properties.
2. The preparation method according to claim 1, characterized in that, The polyethylene glycol in step (1) has a molecular weight of 2000~10000 Da; the mass-to-volume ratio of polyethylene glycol to organic solvent is 1~6 g:10 mL; the organic solvent is... N,N -Dimethylformamide, N,N -Dimethylacetamide, N One or more of methylpyrrolidone and dimethyl sulfoxide.
3. The preparation method according to claim 1, characterized in that, In step (1), isocyanate is dissolved in an organic solvent to form an isocyanate solution, wherein the isocyanate accounts for (15~25)% of the mass of polyethylene glycol; the isocyanate is one or more of isophorone diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, and hexamethylene diisocyanate, and the organic solvent is... N,N -Dimethylformamide, N,N -Dimethylacetamide, N One or more of methylpyrrolidone and dimethyl sulfoxide, wherein the mass-to-volume ratio of isocyanate to organic solvent is 3-4 g: 10 mL.
4. The preparation method according to claim 1, characterized in that, In step (1), the mass ratio of the catalyst to polyethylene glycol is 2-18 µg: 1-6 g; the catalyst is dibutyltin dilaurate, stannous octoate, di(dodecylthio)dibutyltin, triethylamine, N,N One or more of dimethylbenzylamine; the crosslinking reaction is carried out at a temperature of 30~70℃ and for a time of 4~9h.
5. The preparation method according to claim 1, characterized in that, In step (2), the flame retardant accounts for (7~15)% of the mass of polyethylene glycol; the flame retardant is one or more of tetrabromobisphenol A, brominated epoxy resin, decabromodiphenyl ethane, and brominated polystyrene; the photothermal agent accounts for (1~3)% of the mass of polyethylene glycol; the photothermal agent is one or more of 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 1-naphthol, and 2-naphthol, the crosslinking reaction temperature is 60~90℃, and the crosslinking reaction time is 2~8 h.
6. The preparation method according to claim 5, characterized in that, When adding flame retardants and photothermal agents, add the flame retardant first, and allow it to crosslink at 60-90℃ for 3-5 hours. Then add the photothermal agent and allow it to crosslink at 60-90℃ for 2-3 hours. The flame retardant and / or photothermal agent need to be dissolved in an organic solvent before being added. The organic solvent should be... N,N -Dimethylformamide, N,N -Dimethylacetamide, N One or more of methylpyrrolidone and dimethyl sulfoxide, the mass-volume ratio of flame retardant to organic solvent is 1~3 g:10mL, and the mass-volume ratio of photothermal agent to organic solvent is 0.2~0.6 g:10mL.
7. The preparation method according to claim 1, characterized in that, In step (3), the chain extender accounts for (0.5~3.5)% of the mass of polyethylene glycol; the chain extender is one or more of 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol; the chain extension reaction temperature is 75~85℃, and the chain extension reaction time is 1~2h; the coagulation bath temperature of the wet spinning is 55~65℃; the coagulation bath is water; the drying temperature is 40~50℃, and the drying time is 20~25h.
8. Solid-solid phase change fibers with flame-retardant and / or photothermal properties prepared by the preparation method according to any one of claims 1 to 7.
9. The use of the solid-solid phase change fiber with flame-retardant and / or photothermal properties as described in claim 8 in the preparation of products with flame-retardant and / or photothermal properties.
10. The application of the solid-solid phase change fiber with flame retardant properties or with both flame retardant and photothermal properties as described in claim 8 in the preparation of fire-fighting equipment.