Energy storage and temperature regulation chemical fiber and preparation method thereof

Abstract

The invention belongs to the technical field of textile raw materials, and particularly relates to an energy-storage temperature-adjusting chemical fiber and a preparation method thereof. The energy-storing and temperature-regulating chemical fiber adopts a skin-core composite structure, a core layer is made of a bio-based composite phase change material, and a skin layer is made of a fiber-forming polymer matrix material; the bio-based composite phase change material is mainly prepared by blending and granulating a composite functional phase change material energy storage and temperature regulation microcapsule, a polyethylene glycol polymer-based phase change material, poly (3-hydroxybutyrate-3-hydroxyvalerate) and polylactic acid. The preparation method comprises the following steps: preparing composite functional phase-change material energy-storage temperature-regulation microcapsule powder, a polyethylene glycol polymer-based phase-change material, a bio-based composite phase-change material and a fiber-forming polymer matrix material, and finally preparing the energy-storage temperature-regulation chemical fiber. According to the energy storage and temperature regulation chemical fiber and the preparation method thereof, integration of energy storage, temperature regulation, antibiosis, skin friendliness and degradability of the fiber is achieved, meanwhile, the preparation process is optimized, and it is ensured that the performance of the fiber is stable.

Description

Technical Field

[0001] This invention belongs to the field of textile raw material technology, specifically relating to energy storage and temperature regulation chemical fibers and their preparation methods. Background Technology

[0002] Energy storage and temperature regulation fiber is a smart fiber developed based on phase change materials. It can sense changes in external temperature and regulate temperature through the absorption or release of heat during the phase change process, thereby maintaining the stability of the microclimate between the human body and clothing and significantly improving wearing comfort. It has been widely used in textiles, clothing, outdoor equipment, medical protection and other fields, and has become a research hotspot and development direction in the field of smart textile materials.

[0003] Currently, the main methods for preparing energy storage and temperature-regulating fibers include coating, hollow fiber impregnation, microcapsule blending, copolymer spinning, electrospinning, and melt spinning. Among these, melt spinning is the preferred method for energy storage and temperature-regulating chemical fiber preparation due to its simple process, high production efficiency, suitability for large-scale industrial production, and compatibility with the processing technology of mainstream chemical fibers such as polyester and nylon. In engineering and commercial applications, it possesses unparalleled advantages. Existing research focuses primarily on the modification of phase change materials, the preparation of microcapsules, and the optimization of spinning processes to improve the temperature-regulating performance, mechanical properties, and durability of the fibers. For example, patent CN113913160A discloses different types of phase change temperature-regulating fibers and their preparation technologies, all of which involve introducing phase change materials into the fiber system to achieve energy storage and temperature regulation functions.

[0004] However, the preparation and application of existing energy storage and temperature-regulating fibers still have many drawbacks: fibers prepared by coating and hollow impregnation methods have a rough feel, are not washable, have poor durability, and easily lose their temperature-regulating function after repeated washing; although the microcapsule blending method is relatively simple, it requires the preparation of small-diameter microcapsules to meet spinning requirements, which easily leads to supercooling problems, and the microcapsules have poor temperature resistance and are easily destroyed at higher spinning temperatures. At the same time, increasing the amount of microcapsules added to ensure the temperature-regulating effect will significantly affect the physical and mechanical properties of the fiber; the copolymer spinning method has a long reaction time, harsh conditions, and low production efficiency; in addition to the inherent problems of the microcapsule blending method, the fibers prepared by the electrospinning method cannot be used alone and are only suitable for limited applications such as nonwoven fabrics and wadding. Even the widely used melt spinning method faces problems in practical applications such as poor compatibility between phase change materials and fiber-forming polymers, difficulty in balancing fiber temperature regulation performance and mechanical properties, high supercooling, and insufficient thermal conductivity and antistatic properties, which limit the industrial application and performance improvement of energy storage and temperature-regulating chemical fibers.

[0005] Among them, CN114737270A, "A Phase Change Temperature-Regulating Fiber and Its Preparation Method," discloses a phase change temperature-regulating fiber prepared by blending phase change microcapsules with fiber-forming polymers and using melt spinning. This attempt aims to balance the fiber's temperature-regulating and mechanical properties, but it fails to address the overcooling issue caused by the microcapsules and does not optimize the fiber's thermal conductivity and antistatic properties, leaving the fiber's overall performance needing improvement. Additionally, CN112961656A, "A Composite Phase Change Temperature-Regulating Material and Its Preparation Method, Multiple Phase Change Temperature-Regulating Fibers and Their Preparation Methods and Applications," discloses a composite phase change temperature-regulating material and corresponding temperature-regulating fiber. It employs a multiple phase change system to enhance the temperature-regulating effect, but the phase change system used has poor compatibility with the fiber-forming polymer, leading to melt instability during spinning. Furthermore, the fiber's biodegradability and surface moisture absorption properties are not improved, failing to meet the needs of high-end textile applications. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the above-mentioned defects of the prior art and provide an energy storage and temperature regulation chemical fiber and its preparation method, so as to realize the integration of energy storage and temperature regulation, antibacterial and skin-friendly properties, and biodegradability of the fiber, while optimizing the preparation process to ensure stable fiber performance.

[0007] The energy storage and temperature regulation chemical fiber of the present invention adopts a core-sheath composite structure, wherein the core layer is a bio-based composite phase change material and the sheath layer is a fiber-forming polymer matrix material; the bio-based composite phase change material is mainly made of composite functional phase change material energy storage and temperature regulation microcapsules, polyethylene glycol polymer-based phase change material, poly(3-hydroxybutyrate-3-hydroxyvalerate) and polylactic acid blended and granulated.

[0008] Furthermore, the mass ratio of bio-based composite phase change material to fiber-forming polymer matrix material in the fiber is 30~70:70~30. This ratio can be flexibly adjusted according to actual application requirements to ensure that the fiber has both excellent energy storage and temperature regulation performance and good mechanical properties.

[0009] Furthermore, the particle size D90 of the composite functional phase change material energy storage and temperature regulation microcapsules is ≤1.392μm. The refined design of the microcapsules can improve their dispersion uniformity in the core material, avoid agglomeration, and thus improve the temperature regulation stability and mechanical properties of the fiber.

[0010] Furthermore, the mass ratio of the composite functional phase change material energy storage and temperature regulation microcapsules, polyethylene glycol polymer-based phase change material, poly(3-hydroxybutyrate-3-hydroxyvalerate), and polylactic acid is 100:30~50:20~30:10~20. Poly(3-hydroxybutyrate-3-hydroxyvalerate) possesses excellent antibacterial properties, while polylactic acid exhibits excellent natural skin-friendly properties and biodegradability. Their synergistic effect endows the fiber with good functionality and environmental friendliness. The polyethylene glycol polymer-based phase change material can synergistically enhance the energy storage and temperature regulation performance of the fiber with the microcapsules, achieving precise temperature control.

[0011] The method for preparing the energy storage and temperature regulation chemical fiber of the present invention includes the following steps: (1) Preparation of composite functional phase change material energy storage and temperature regulation microcapsule powder The phase change material (PCM) was melted at 40–50 °C. The molten PCM was then mixed uniformly with methyl methacrylate, allyl methacrylate, conductive nucleating agent monomers, and thermally conductive nucleating agent in a specific ratio. This mixture was added to an emulsification reactor containing emulsifier, initiator, and distilled water. The mixture was emulsified and dispersed under oxygen-free conditions at 40–50 °C and a stirring speed of 1800–2500 r / min until a stable emulsion with a particle size D90 ≤ 0.956 μm was formed. The temperature was then raised to 70–80 °C and the stirring speed was 500–800 r / min for polymerization. The reaction was continued for 60–90 min until no irritating odor was detected, ensuring complete polymerization. After the reaction, the temperature was lowered to 15–25 °C and the pH adjusted to 7–8.5 to prepare composite functional PCM energy storage and temperature regulation microcapsules with a particle size D90 ≤ 1.392 μm. These microcapsule powders were then obtained using conventional spray drying methods for later use.

[0012] The phase change material is one of n-octadecane, n-nonadecane, and n-eicosane, which has a suitable phase change temperature to meet the needs of human comfort temperature range regulation. The conductive nucleating agent monomer is aniline, which polymerizes into polyaniline during microcapsule preparation. Polyaniline is located in the core and wall of the capsule, giving the microcapsule good conductivity and serving as a nucleating agent in the crystallization process of the phase change material, reducing the supercooling of the microcapsule and improving the temperature regulation response speed. The thermally conductive nucleating agent is hydroxylated boron nitride nanosheets, which are purchased as modified products to improve their compatibility in the oil phase material, thereby improving the thermal conductivity of the microcapsule and accelerating heat transfer and storage. The emulsifier is one of styrene-maleic anhydride copolymer sodium salt, Span-80, and sodium dodecyl sulfate (SDS), which can ensure the stability of the emulsion and avoid microcapsule aggregation. The initiator is ammonium persulfate, benzoyl peroxide, or azobisisobutyronitrile, which can effectively initiate the polymerization reaction.

[0013] The mass ratio of each raw material is as follows: phase change material: methyl methacrylate: allyl methacrylate: conductive nucleating agent monomer: thermally conductive nucleating agent: emulsifier: initiator: distilled water = 100: 50~70: 10~30: 10~20: 2~5: 15~30: 0.5~2.5: 500~800. This ratio can ensure the structural integrity and performance stability of the microcapsules.

[0014] (2) Preparation of polyethylene glycol polymer-based phase change materials Dry butyrolactam or caprolactam is slowly added to toluene-2,4-diisocyanate (purity ≥98%) and reacted at 75-85℃ for 25-40 min to obtain isocyanate-modified butyrolactam or caprolactam; dried polyethylene glycol (PEG) is added to the above-prepared isocyanate-modified butyrolactam and reacted at 75-85℃ for 50-80 min to obtain PEG-modified acylated butyrolactam or caprolactam block copolymer; the butyrolactam or caprolactam is heated at 120-135℃ until completely melted. Then, NaOH is added, and the mixture is vacuum dehydrated at 140~150℃ for 20~30 min, and then cooled to 100~110℃ for later use. The PEG-modified acylated butyrolactam or caprolactam block copolymer is added to the mixed solution of butyrolactam or caprolactam and sodium hydroxide, and stirred thoroughly to obtain polybutyrolactam or polycaprolactam modified polyethylene glycol reactant. Then, the temperature is raised to 170~185℃ and reacted for 10~20 min to prepare polybutyrolactam or polycaprolactam modified polyethylene glycol copolymer, i.e. polyethylene glycol polymer-based phase change material.

[0015] In the polybutyrolactam or polycaprolactam modified polyethylene glycol copolymer, the mass percentages of butyrolactam or caprolactam, toluene-2,4-diisocyanate, and polyethylene glycol are 42-30%, 8-5%, and 50-65%, respectively; the polyethylene glycol is one of a weight-average molecular weight of 1500, 2000, 4000, 6000, or 8000, which can be flexibly selected according to the required temperature range.

[0016] (3) Preparation of bio-based composite phase change materials The composite functional phase change material energy storage and temperature regulation microcapsule powder prepared in step (1), the polyethylene glycol polymer-based phase change material prepared in step (2), poly(3-hydroxybutyrate-3-hydroxyvalerate), and polylactic acid were mixed in a mass ratio of 100:30~50:20~30:10~20 and dried together to ensure that the moisture content was below 500ppm, so as to avoid the moisture affecting the subsequent granulation and spinning performance. Then, the mixture was added to a single-screw extruder for granulation. The extrusion temperature was 175~185℃, the vacuum degree was -0.05~-0.1MPa, the screw speed was 60~100r / min, and the blending time was 20~30min to obtain the bio-based composite phase change material.

[0017] In this step, poly(3-hydroxybutyrate-3-hydroxyvalerate) has good antibacterial properties and can effectively inhibit bacterial growth; polylactic acid has good natural skin-friendly properties. It is derived from renewable plant resources, does not rely on petroleum, and its waste can be completely decomposed into carbon dioxide and water by microorganisms under composting conditions, leaving no microplastic residue. Its carbon footprint is only 10%-15% of that of traditional chemical fibers, achieving a closed-loop carbon cycle and combining environmental protection and skin-friendliness. The two, together with microcapsules and polyethylene glycol polymer-based phase change materials, can endow the core material with multiple functions such as energy storage and temperature regulation, antibacterial properties, skin-friendliness, and biodegradability.

[0018] (4) Preparation of fiber-forming polymer matrix materials The fiber-forming polymer and the thermally conductive material are dried to a moisture content of less than 500 ppm, then mixed in a mass ratio of 100:2~5 and added to a single-screw extruder for granulation to obtain the fiber-forming polymer matrix material.

[0019] The fiber-forming polymer is a polymer that can be melt-spun, preferably one of polylactic acid, polyester, and polyamide. The appropriate fiber-forming polymer can be selected according to the application scenario of the fiber. The thermally conductive material is hydroxylated boron nitride nanosheets. Purchasing organically modified products can improve the compatibility with the fiber-forming polymer matrix, reduce interface defects, and at the same time construct a complete thermally conductive network, reduce interface thermal resistance, improve the thermal conductivity of the skin material, and thus improve the overall temperature regulation efficiency and mechanical properties of the fiber.

[0020] The temperature of the single-screw extruder is the melting temperature of the fiber-forming polymer. The melting temperature varies depending on the fiber-forming polymer used. The screw speed is 100~120 r / min, and the vacuum degree is -0.05~-0.1 MPa to ensure that the granulation process proceeds smoothly and to obtain matrix particles with uniform particle size and stable performance.

[0021] (5) Preparation of energy storage and temperature regulation chemical fibers After drying, the bio-based composite phase change material prepared in step (3) and the fiber-forming polymer matrix material prepared in step (4) are dried to a moisture content of less than 500 ppm. Then, they are used as core material and skin material respectively and melt extruded by screw. The melt is filtered and degassed to remove impurities and bubbles to ensure the uniformity of the melt. The melt then enters a metering pump and is kept warm by an independent melt pipe and a secondary box to maintain a stable melt temperature. The melt is then sprayed out in a core-skin composite component to form a filament bundle. The filament bundle is cooled by air at 20~35℃ and by ring blowing to obtain nascent fibers with a core-skin structure. The nascent fibers are then processed by fiber treatment processes such as stretching, shaping, plasma etching, crimping or twisting to produce energy storage and temperature regulation chemical fiber filaments, or the nascent fibers are further processed by stretching, shaping, plasma etching, cutting and other processes to produce energy storage and temperature regulation short fibers.

[0022] Preferably, the specific processing conditions for plasma etching are as follows: the output power of the plasma treatment is 160W~260W, the treatment time is 60~90s, the reaction gas is air, and the reaction pressure is 60~90Pa; after plasma treatment, the surface structure of the fiber is etched, the surface area increases, thereby improving its moisture absorption and enhancing the wearability of the fiber.

[0023] The energy storage and temperature regulation chemical fiber of this invention has a core-sheath structure, with a prepared bio-based composite phase change material as the core layer and a melt-spinning polymer matrix material as the sheath layer, prepared by a composite melt spinning method. The bio-based composite phase change material is biodegradable and is prepared by melt granulation of poly(3-hydroxybutyrate-3-hydroxyvalerate) and polylactic acid as a mixed matrix, and by adding the prepared composite functional phase change material energy storage and temperature regulation microcapsules and the synthesized polyethylene glycol polymer-based phase change material as the composite phase change material. This chemical fiber exhibits excellent heat storage and temperature regulation properties, with a melting temperature range of 25.8–50.6℃, a crystallization temperature range of 10.8–44.3℃, a melting enthalpy of 23.61–71.56 J / g, a crystallization enthalpy of 22.15–70.67 J / g, a tensile strength of 2.91–3.65 cN / dtex, and a tensile elongation of 23.9–39.6%. The fiber's thermal conductivity at 10℃ is 0.82–0.95 W / m·K. The prepared chemical fiber also shows improved antistatic properties, with a volume resistivity of 8.9 × 10⁻⁶. 8 ~6.2×10 9 Ω·cm.

[0024] Compared with the prior art, the beneficial effects of the present invention are: (1) This invention uses a combination of phase change material energy storage and temperature regulation microcapsules and polyethylene glycol polymer-based energy storage and temperature regulation materials, which expands the applicability and scope of application of energy storage and temperature regulation materials. First, the capsule wall of the energy storage and temperature regulation microcapsules protects the phase change material; by preparing a bio-based composite phase change material, poly(3-hydroxybutyrate-3-hydroxyvalerate) and polylactic acid are used to coat the energy storage and temperature regulation microcapsules and polyethylene glycol polymer-based energy storage and temperature regulation materials, further reducing the damage to the energy storage and temperature regulation materials; then, combined with the outer layer protection of the fiber-forming polymer matrix material, the stability of the fiber and the energy storage and temperature regulation performance are greatly improved.

[0025] (2) In the process of preparing phase change material energy storage and temperature regulation microcapsules, the present invention not only reduces the supercooling of the energy storage and temperature regulation microcapsules by adding conductive nucleating agent monomers and thermally conductive nucleating agents, but also utilizes the conductive effect of the conductive nucleating agent monomers after polymerization and the thermally conductive effect of the thermally conductive nucleating agents to not only endow the energy storage and temperature regulation microcapsules with electrical and thermal conductivity, but also endow the core layer and even the fibers with good electrical and thermal conductivity of the bio-based composite phase change material as the core layer; moreover, the conductive nucleating agents and thermally conductive nucleating agents used are all organic materials, which improves the compatibility of the matrix material.

[0026] (3) This invention utilizes poly(3-hydroxybutyrate-3-hydroxyvalerate) and polylactic acid to mix and granulate with phase change material energy storage and temperature regulation microcapsules and polyethylene glycol polymer-based energy storage and temperature regulation materials. Then, it uses a melt composite spinning method to prepare energy storage and temperature regulation chemical fibers with a fiber-forming polymer matrix material as the skin and the prepared bio-based composite phase change material as the core layer. The combination of the bio-based composite phase change material poly(3-hydroxybutyrate-3-hydroxyvalerate) and polylactic acid with the fiber-forming polymer matrix material of the skin layer enhances the adhesion between the skin layer and the core layer material, making the fiber structure stable. At the same time, the poly(3-hydroxybutyrate-3-hydroxyvalerate) and polylactic acid in the bio-based composite phase change material have good functionality, such as antibacterial and skin-friendly properties, giving the chemical fiber better functionality. In addition, the prepared chemical fiber can also be partially biodegradable, making it low-carbon and environmentally friendly.

[0027] (4) The present invention adds thermally conductive materials to improve the thermal conductivity of chemical fibers, enabling the chemical fibers to transfer heat quickly and allowing the fibers to better perform their energy storage and temperature regulation performance; by controlling the vacuum degree during granulation, the bubbles are reduced, and the difficulty of subsequent degassing is reduced. Detailed Implementation

[0028] The present invention will be further described below with reference to specific embodiments.

[0029] All raw materials and additives used below are commercially available products.

[0030] The testing standards for the fibers in the following examples and comparative examples are as follows: The melting temperature range, crystallization temperature range, melting enthalpy, and crystallization enthalpy were tested according to FZ / T50061-2023 "Test Method for Heat Storage and Release Performance of Chemical Fiber Phase Change Materials - Differential Scanning Calorimetry (DSC)"; Breaking strength and breaking elongation tests: for short fibers, the test method is GB / T 14337-2022 "Test Method for Tensile Properties of Chemical Fibers (Short Fibers)"; for filaments, the test method is GB / T14344-2022 "Test Method for Tensile Properties of Chemical Fibers (Filaments)". The thermal conductivity of the fiber was tested according to GB / T10297-2015 "Determination of thermal conductivity of non-metallic solid materials - hot wire method"; The volume resistivity test is conducted according to FZ / T50035-2016 "Test Method for Resistance of Synthetic Fiber Filaments". Short fibers are tested according to this standard before they are cut. The biodegradability test was conducted according to GB / T19277.1-2011 "Determination of the final aerobic biodegradability of materials under controlled composting conditions—Method for determining the release of carbon dioxide—Part 1: General Method"; Moisture absorption is expressed as moisture regain, and its testing is based on GB / T 6503-2017 "Test Method for Moisture Regain of Chemical Fibers".

[0031] Hydroxylated boron nitride nanosheets: purity: 99wt%; sheet diameter: 0.1-0.4µm; commercially available from Jiangsu Xianfeng Nanomaterials Technology Co., Ltd. Toluene-2,4-diisocyanate: purity ≥98wt%, commercially available, from Shandong Jinyueyuan New Materials Co., Ltd.; Poly(3-hydroxybutyrate-3-hydroxyvalerate): granular, from Nanjing Hesu Times Antibacterial Materials Technology Co., Ltd. Example 1

[0032] This invention prepares energy-storing, temperature-regulating polyamide 6 short fibers with a specification of 2.22 dtex × 51 mm: (1) Preparation of composite functional phase change material energy storage and temperature regulation microcapsule powder The phase change material was melted at 50°C. The molten phase change material was then mixed with methyl methacrylate, allyl methacrylate, conductive nucleating agent monomer, and thermally conductive nucleating agent in a specific ratio. This mixture was added to an emulsification reactor containing emulsifier, initiator, and distilled water. The mixture was emulsified and dispersed at 40°C and 1800 rpm under oxygen-free conditions until a stable emulsion with a particle size D90 = 0.758 μm was formed. The temperature was then raised to 70°C and the stirring speed was 500 rpm for polymerization. The reaction was continued for 90 min until no irritating odor was detected. After the reaction, the temperature was lowered to 15°C and the pH was adjusted to 7 to prepare composite functional phase change material energy storage and temperature regulation microcapsules (particle size D90 = 1.156 μm). The energy storage and temperature regulation microcapsule powder was obtained using a conventional spray drying method for later use.

[0033] The phase change material is n-eicosane, the emulsifier is sodium salt of styrene-maleic anhydride copolymer, the initiator is ammonium persulfate, the conductive nucleating agent monomer is aniline, and the thermally conductive nucleating agent is hydroxylated boron nitride nanosheets; the mass ratio of each raw material is: phase change material: methyl methacrylate: allyl methacrylate: conductive nucleating agent monomer: thermally conductive nucleating agent: emulsifier: initiator: distilled water = 100:70:30:10:2:30:2.5:500.

[0034] (2) Preparation of polyethylene glycol polymer-based phase change materials Dried butyrolactam was slowly added to toluene-2,4-diisocyanate (purity ≥98%) and reacted at 75°C for 40 min to obtain isocyanate-modified butyrolactam. Dried polyethylene glycol (weight average molecular weight 2000) was added to the isocyanate-modified butyrolactam prepared above and reacted at 75°C for 80 min to obtain PEG-modified acylated butyrolactam block copolymer. Butyrolactam was heated to 120°C until completely melted, then NaOH was added, and the mixture was vacuum dehydrated at 140°C for 30 min and cooled to 100°C for later use. The PEG-modified acylated butyrolactam block copolymer was added to a mixed solution of butyrolactam and sodium hydroxide and stirred thoroughly to obtain polybutyrolactam-modified polyethylene glycol reactant. The mixture was then heated to 170°C and reacted for 20 min to prepare polybutyrolactam-modified polyethylene glycol copolymer (i.e., polyethylene glycol polymer-based phase change material).

[0035] In the polybutyrolactam-modified polyethylene glycol copolymer, the mass percentages of butyrolactam:toluene-2,4-diisocyanate:polyethylene glycol are 42:8:50.

[0036] (3) Preparation of bio-based composite phase change materials The composite functional phase change material energy storage and temperature regulation microcapsule powder prepared in step (1), the polyethylene glycol polymer-based phase change material prepared in step (2), poly(3-hydroxybutyric acid-3-hydroxyvalerate), and polylactic acid were mixed evenly in a mass ratio of 100:30:30:20 and dried together until the moisture content was 410ppm (≤500ppm). Then the mixture was added to a single screw extruder for granulation, with the temperature controlled at 175℃, the vacuum degree at -0.1MPa, the screw speed at 60r / min, and the mixing time at 30min, to obtain the bio-based composite phase change material.

[0037] (4) Preparation of fiber-forming polymer matrix materials The fiber-forming polymer and the thermally conductive material are dried to a moisture content of 115 ppm (≤500 ppm), then mixed evenly at a mass ratio of 100:2, and added to a single-screw extruder for granulation to obtain the fiber-forming polymer matrix material.

[0038] The fiber-forming polymer is polyamide 6, and the thermally conductive material is hydroxylated boron nitride nanosheets; the temperature of the single-screw extruder is 260℃ (melting temperature of polyamide 6), the screw speed is 100r / min, and the vacuum degree is -0.1MPa.

[0039] (5) Preparation of energy storage and temperature regulation polyamide 6 short fibers The bio-based composite phase change material from step (3) and the fiber-forming polymer matrix material from step (4) are dried to a moisture content of 110 ppm (≤500 ppm) and used as the core material and skin material, respectively, by screw melt extrusion. The melt is filtered and degassed before entering the metering pump, and is kept warm through an independent melt tube and a secondary box. It is then sprayed out in the core-skin composite component to form a filament bundle. The filament bundle is cooled by air at 20°C and ring blowing to obtain nascent fibers with a core-skin structure. The nascent fibers are then processed by stretching, shaping, plasma etching, and cutting to produce energy storage temperature-regulating polyamide 6 short fibers with a specification of 2.22 dtex × 51 mm.

[0040] The mass ratio of the bio-based composite phase change material to the fiber-forming polymer matrix material in the fiber is 30:70; the specific processing conditions for the plasma etching are: output power 150W, action time 50s, reaction gas is air, and reaction pressure 50Pa.

[0041] The properties of the prepared energy-storage temperature-regulating polyamide 6 short fibers with a specification of 2.22 dtex × 51 mm were tested and are as follows: melt temperature range of 26.5~50.6℃, crystallization temperature range of 16.3~44.3℃, enthalpy of melting of 23.61 J / g, enthalpy of crystallization of 22.15 J / g, tensile strength of 3.65 cN / dtex, elongation at break of 23.9%, thermal conductivity at 10℃ of 0.82 W / m·K, and volume resistivity of 6.2 × 10⁻⁶. 9 It has a strength of Ω·cm (good antistatic properties), stable structure, and can be partially degraded after disposal. Its biodegradability is 7.96%, and its hygroscopicity (moisture regain) is 5.2% higher than that of conventional polyamide 6 short fiber (the moisture regain of conventional polyamide 6 short fiber is 4.5%). Example 2

[0042] This invention prepares energy-storing and temperature-regulating polyester (PBT) staple fibers with a specification of 1.67 dtex × 38 mm: (1) Preparation of composite functional phase change material energy storage and temperature regulation microcapsule powder The phase change material was melted at 48℃. The molten phase change material was then mixed uniformly with methyl methacrylate, allyl methacrylate, conductive nucleating agent monomer, and thermally conductive nucleating agent in a specific ratio. This mixture was added to an emulsification reactor containing emulsifier, initiator, and distilled water. The mixture was emulsified and dispersed under oxygen-free conditions at 42.5℃ and a stirring speed of 1950 r / min until a stable emulsion with a particle size D90 = 0.826 μm was formed. The temperature was then raised to 73.5℃ and the stirring speed was 590 r / min for polymerization. The reaction was continued for 82 min until no irritating odor was detected. After the reaction, the temperature was lowered to 18℃ and the pH was adjusted to 7.2 to prepare composite functional phase change material energy storage and temperature regulation microcapsules (particle size D90 = 1.198 μm). The energy storage and temperature regulation microcapsule powder was obtained using a conventional spray drying method for later use.

[0043] The phase change material is n-eicosane, the emulsifier is Span-80, the initiator is ammonium persulfate, the conductive nucleating agent monomer is aniline, and the thermally conductive nucleating agent is hydroxylated boron nitride nanosheets; the mass ratio of each raw material is: phase change material: methyl methacrylate: allyl methacrylate: conductive nucleating agent monomer: thermally conductive nucleating agent: emulsifier: initiator: distilled water = 100:65:25:12.5:2.5:26:2.0:580.

[0044] (2) Preparation of polyethylene glycol polymer-based phase change materials Dried butyrolactam was slowly added to toluene-2,4-diisocyanate (purity ≥98%) and reacted at 77.6℃ for 36 min to obtain isocyanate-modified butyrolactam. Dried polyethylene glycol (weight average molecular weight 8000) was added to the isocyanate-modified butyrolactam prepared above and reacted at 76.8℃ for 72 min to obtain PEG-modified acylated butyrolactam block copolymer. Butyrolactam was heated to 125℃ until completely melted, then NaOH was added, and the mixture was vacuum dehydrated at 143℃ for 27 min and cooled to 102℃ for later use. The PEG-modified acylated butyrolactam block copolymer was added to a mixed solution of butyrolactam and sodium hydroxide and stirred thoroughly to obtain polybutyrolactam-modified polyethylene glycol reactant. The mixture was then heated to 173℃ and reacted for 18 min to prepare polybutyrolactam-modified polyethylene glycol copolymer (i.e., polyethylene glycol polymer-based phase change material).

[0045] In the polybutyrolactam-modified polyethylene glycol copolymer, the mass percentages of butyrolactam:toluene-2,4-diisocyanate:polyethylene glycol are 38:7.5:53.

[0046] (3) Preparation of bio-based composite phase change materials The composite functional phase change material energy storage and temperature regulation microcapsule powder prepared in step (1), the polyethylene glycol polymer-based phase change material prepared in step (2), poly(3-hydroxybutyric acid-3-hydroxyvalerate), and polylactic acid were mixed evenly in a mass ratio of 100:35:27:16 and dried together until the moisture content was 350ppm (≤500ppm). Then the mixture was added to a single screw extruder for granulation, with the temperature controlled at 177.5℃, the vacuum degree at -0.09MPa, the screw speed at 70r / min, and the mixing time at 28min, to obtain the bio-based composite phase change material.

[0047] (4) Preparation of fiber-forming polymer matrix materials The fiber-forming polymer and the thermally conductive material are dried to a moisture content of 106 ppm (≤500 ppm), then mixed evenly at a mass ratio of 100:2.7, and added to a single-screw extruder for granulation to obtain the fiber-forming polymer matrix material.

[0048] The fiber-forming polymer is polyester (PBT), and the thermally conductive material is hydroxylated boron nitride nanosheets; the temperature of the single-screw extruder is 272℃ (PBT melting temperature), the screw speed is 105 r / min, and the vacuum degree is -0.09 MPa.

[0049] (5) Preparation of energy storage temperature-regulating polyester (PBT) short fibers The bio-based composite phase change material from step (3) and the fiber-forming polymer matrix material from step (4) are dried to a moisture content of 95 ppm (≤500 ppm) and used as the core material and skin material, respectively, by screw melt extrusion. The melt is filtered and degassed before entering the metering pump, and is kept warm through an independent melt tube and a secondary box. It is then sprayed out in the core-skin composite component to form a filament bundle. The filament bundle is cooled by air at 23°C and ring blowing to obtain nascent fibers with a core-skin structure. The nascent fibers are then subjected to stretching, shaping, plasma etching, and cutting processes to produce energy storage temperature-regulating polyester (PBT) short fibers with a specification of 1.67 dtex × 38 mm.

[0050] The mass ratio of the bio-based composite phase change material to the fiber matrix material in the fiber is 40:60; the specific processing conditions for the plasma etching are: output power 175W, action time 65s, reaction gas is air, and reaction pressure 65Pa.

[0051] The properties of the prepared energy storage temperature-regulating polyester (PBT) staple fiber with a specification of 1.67 dtex × 38 mm were tested as follows: melt temperature range of 26.2~50.1℃, crystallization temperature range of 15.7~43.9℃, enthalpy of melting of 34.26 J / g, enthalpy of crystallization of 33.85 J / g, tensile strength of 3.40 cN / dtex, elongation at break of 26.5%, thermal conductivity at 10℃ of 0.84 W / m·K, and volume resistivity of 3.1 × 10⁻⁶. 9 It has a Ω·cm (good antistatic properties), stable structure, and can be partially degraded after disposal. Its biodegradability is 9.13%, and its hygroscopicity (moisture regain) is 5.7% higher than that of conventional polyester (PBT) staple fiber (the moisture regain of conventional polyester (PBT) staple fiber is 0.4%). Example 3

[0052] This invention prepares energy-storing and temperature-regulating polyester (PET) filaments with a specification of 113 dtex / 48f: (1) Preparation of composite functional phase change material energy storage and temperature regulation microcapsule powder The phase change material was melted at 45°C. The molten phase change material was then mixed uniformly with methyl methacrylate, allyl methacrylate, conductive nucleating agent monomer, and thermally conductive nucleating agent in a specific ratio. This mixture was added to an emulsification reactor containing emulsifier, initiator, and distilled water. The mixture was emulsified and dispersed under oxygen-free conditions at 44.9°C and a stirring speed of 2150 r / min until a stable emulsion with a particle size D90 = 0.885 μm was formed. The temperature was then raised to 76°C and the stirring speed was 690 r / min for polymerization. The reaction was continued for 76 min until no irritating odor was detected. After the reaction, the temperature was lowered to 22°C and the pH was adjusted to 7.6 to prepare composite functional phase change material energy storage and temperature regulation microcapsules (particle size D90 = 1.221 μm). The energy storage and temperature regulation microcapsule powder was obtained using a conventional spray drying method for later use.

[0053] The phase change material is n-nonadecane, the emulsifier is Span-80, the initiator is benzoyl peroxide, the conductive nucleating agent monomer is aniline, and the thermally conductive nucleating agent is hydroxylated boron nitride nanosheets; the mass ratio of each raw material is: phase change material: methyl methacrylate: allyl methacrylate: conductive nucleating agent monomer: thermally conductive nucleating agent: emulsifier: initiator: distilled water = 100:60:20:15:3.5:23:1.5:650.

[0054] (2) Preparation of polyethylene glycol polymer-based phase change materials Dried caprolactam was slowly added to toluene-2,4-diisocyanate (purity ≥98%) and reacted at 80℃ for 32 min to obtain isocyanate-modified caprolactam. Dried polyethylene glycol (weight average molecular weight 4000) was added to the above-prepared isocyanate-modified caprolactam and reacted at 80℃ for 65 min to obtain PEG-modified acylated caprolactam block copolymer. After caprolactam was heated to 128℃ until completely melted, NaOH was added, and vacuum dehydration was carried out at 145℃ for 25 min, followed by cooling to 105℃ for later use. The PEG-modified acylated caprolactam block copolymer was added to a mixed solution of caprolactam and sodium hydroxide and stirred thoroughly to obtain polycaprolactam-modified polyethylene glycol reactant. Then, the temperature was raised to 176℃ and reacted for 15 min to prepare polycaprolactam-modified polyethylene glycol copolymer (i.e., polyethylene glycol polymer-based phase change material).

[0055] In the polycaprolactam-modified polyethylene glycol copolymer, the mass percentages of caprolactam: toluene-2,4-diisocyanate: polyethylene glycol are 35:7:58.

[0056] (3) Preparation of bio-based composite phase change materials The composite functional phase change material energy storage and temperature regulation microcapsule powder prepared in step (1), the polyethylene glycol polymer-based phase change material prepared in step (2), poly(3-hydroxybutyric acid-3-hydroxyvalerate), and polylactic acid were mixed evenly in a mass ratio of 100:40:25:15 and dried together until the moisture content was 220ppm (≤500ppm). Then, the mixture was added to a single screw extruder for granulation, with the temperature controlled at 180℃, the vacuum degree at -0.08MPa, the screw speed at 80r / min, and the mixing time at 25min, to obtain the bio-based composite phase change material.

[0057] (4) Preparation of fiber-forming polymer matrix materials The fiber-forming polymer and the thermally conductive material are dried to a moisture content of 98 ppm (≤500 ppm), then mixed evenly at a mass ratio of 100:3.5, and added to a single-screw extruder for granulation to obtain the fiber-forming polymer matrix material.

[0058] The fiber-forming polymer is polyester (PET), and the thermally conductive material is hydroxylated boron nitride nanosheets; the temperature of the single-screw extruder is 275℃ (polyester melt temperature), the screw speed is 110 r / min, and the vacuum degree is -0.08 MPa.

[0059] (5) Preparation of energy storage temperature-regulating polyester (PET) filament The bio-based composite phase change material from step (3) and the fiber-forming polymer matrix material from step (4) are dried to a moisture content of 110 ppm (≤500 ppm) and used as the core material and sheath material, respectively, by screw melt extrusion. The melt is filtered and degassed before entering the metering pump, and is kept warm through an independent melt tube and a secondary box. It is then sprayed out in the core-sheath composite component to form a filament bundle. The filament bundle is cooled by air at 28°C and ring blowing to obtain nascent fibers with a core-sheath structure. The nascent fibers are then subjected to stretching, shaping, plasma etching, and twisting processes to produce energy storage temperature-regulating polyester (PET) filaments with a specification of 113 dtex / 48f.

[0060] The mass ratio of the bio-based composite phase change material to the fiber matrix material in the fiber is 50:50; the specific processing conditions for the plasma etching are: output power 200W, action time 80s, reaction gas is air, and reaction pressure 75Pa.

[0061] The prepared energy storage temperature-regulating polyester (PET) filaments were tested and found to have the following properties: melting temperature range of 26.1~44.3℃, crystallization temperature range of 16.2~41.2℃, melting enthalpy of 41.16J / g, crystallization enthalpy of 40.01J / g, breaking strength of 3.31cN / dtex, elongation at break of 29.5%, thermal conductivity at 10℃ of 0.87W / m·K, and volume resistivity of 1.9×10⁻⁶. 8 It has excellent antistatic properties (Ω·cm), stable structure, and can be partially degraded after disposal. Its biodegradability is 10.65%, and its hygroscopicity (moisture regain) is 6.5% higher than that of conventional polyester (PET) filament (the moisture regain of conventional polyester (PET) filament is 0.4%). Example 4

[0062] This invention prepares energy-storage temperature-regulating polylactic acid filaments with a specification of 132 dtex / 78 f: (1) Preparation of composite functional phase change material energy storage and temperature regulation microcapsule powder The phase change material was melted at 40°C. The molten phase change material was then mixed uniformly with methyl methacrylate, allyl methacrylate, conductive nucleating agent monomer, and thermally conductive nucleating agent in a specific ratio. This mixture was added to an emulsification reactor containing emulsifier, initiator, and distilled water. The mixture was emulsified and dispersed at 50°C and 2500 rpm under oxygen-free conditions until a stable emulsion with a particle size D90 = 0.956 μm was formed. The temperature was then raised to 80°C and the stirring speed was 800 rpm for polymerization. The reaction was continued for 60 min until no irritating odor was detected. After the reaction, the temperature was lowered to 25°C and the pH was adjusted to 8.5 to prepare composite functional phase change material energy storage and temperature regulation microcapsules (particle size D90 = 1.392 μm, within the specified range). The energy storage and temperature regulation microcapsule powder was obtained using a conventional spray drying method for later use.

[0063] The phase change material is n-octadecane, the emulsifier is sodium dodecyl sulfate (SDS), the initiator is azobisisobutyronitrile, the conductive nucleating agent monomer is aniline, and the thermally conductive nucleating agent is hydroxylated boron nitride nanosheets; the mass ratio of each raw material is: phase change material: methyl methacrylate: allyl methacrylate: conductive nucleating agent monomer: thermally conductive nucleating agent: emulsifier: initiator: distilled water = 100:50:10:20:5:15:0.5:800.

[0064] (2) Preparation of polyethylene glycol polymer-based phase change materials Dried caprolactam was slowly added to toluene-2,4-diisocyanate (purity ≥98%) and reacted at 85°C for 25 min to obtain isocyanate-modified caprolactam. Dried polyethylene glycol (weight average molecular weight 6000) was added to the prepared isocyanate-modified caprolactam and reacted at 85°C for 50 min to obtain PEG-modified acylated caprolactam block copolymer. After caprolactam was heated to 135°C until completely melted, NaOH was added, and the mixture was vacuum dehydrated at 150°C for 20 min and cooled to 110°C for later use. The PEG-modified acylated caprolactam block copolymer was added to a mixed solution of caprolactam and sodium hydroxide and stirred thoroughly to obtain polycaprolactam-modified polyethylene glycol reactant. The mixture was then heated to 185°C and reacted for 10 min to prepare polycaprolactam-modified polyethylene glycol copolymer (i.e., polyethylene glycol polymer-based phase change material).

[0065] In the polycaprolactam-modified polyethylene glycol copolymer, the mass percentages of caprolactam: toluene-2,4-diisocyanate: polyethylene glycol are 30:5:65.

[0066] (3) Preparation of bio-based composite phase change materials The composite functional phase change material energy storage and temperature regulation microcapsule powder prepared in step (1), the polyethylene glycol polymer-based phase change material prepared in step (2), poly(3-hydroxybutyric acid-3-hydroxyvalerate), and polylactic acid were mixed evenly in a mass ratio of 100:50:20:10 and dried together until the moisture content was 155ppm (≤500ppm). Then the mixture was added to a single screw extruder for granulation, with the temperature controlled at 185℃, the vacuum degree at -0.05MPa, the screw speed at 100r / min, and the mixing time at 20min, to obtain the bio-based composite phase change material.

[0067] (4) Preparation of fiber-forming polymer matrix materials The fiber-forming polymer and the thermally conductive material are dried to a moisture content of 95 ppm (≤500 ppm), then mixed evenly at a mass ratio of 100:5, and added to a single-screw extruder for granulation to obtain the fiber-forming polymer matrix material.

[0068] The fiber-forming polymer is polylactic acid, and the thermally conductive material is hydroxylated boron nitride nanosheets; the temperature of the single-screw extruder is 226℃ (the melting temperature of polylactic acid), the screw speed is 120 r / min, and the vacuum degree is -0.05 MPa.

[0069] (5) Preparation of energy storage and temperature regulation polylactic acid filaments The bio-based composite phase change material from step (3) and the fiber-forming polymer matrix material from step (4) are dried to a moisture content of 101ppm (≤500ppm) and used as the core material and skin material, respectively, by screw melt extrusion. The melt is filtered and degassed before entering the metering pump, and is kept warm through an independent melt tube and a secondary box. It is then sprayed out in the core-skin composite component to form a filament bundle. The filament bundle is cooled by air at 35°C and ring blowing to obtain nascent fibers with a core-skin structure. The nascent fibers are then subjected to stretching, shaping, plasma etching, and crimping processes to produce energy storage and temperature-regulating polylactic acid filaments with a specification of 132dtex / 78f.

[0070] The mass ratio of the bio-based composite phase change material to the fiber matrix material in the fiber is 70:30; the specific processing conditions for the plasma etching are: output power 250W, action time 100s, reaction gas is air, and reaction pressure 90Pa.

[0071] The prepared energy storage temperature-regulating polylactic acid filaments were tested and found to have the following properties: melting temperature range of 25.8~37.8℃, crystallization temperature range of 10.8~33.7℃, melting enthalpy of 61.56 J / g, crystallization enthalpy of 60.67 J / g, tensile strength of 2.91 cN / dtex, elongation at break of 39.6%, thermal conductivity at 10℃ of 0.95 W / m·K, and volume resistivity of 8.9 × 10⁻⁶. 8 It has a strength of Ω·cm (good antistatic properties), stable structure, and can be partially degraded after disposal. Its biodegradability is 40.55%, and its hygroscopicity (moisture regain) is 7.3% higher than that of conventional polylactic acid filament (the moisture regain of conventional polylactic acid filament is 0.4%).

[0072] Comparative Example 1 Compared with Example 4, this comparative example does not add conductive nucleating agent monomer (aniline) in the preparation steps of composite functional phase change material energy storage and temperature regulation microcapsules. The remaining preparation steps, raw material types and amounts, and process parameters are exactly the same as in Example 3, and energy storage and temperature regulation polylactic acid filaments with specifications of 132dtex / 78f are prepared.

[0073] The obtained fiber properties were tested and are as follows: melting temperature range of 25.5~37.3℃, crystallization temperature range of 13.2~34.9℃, melting enthalpy of 61.39J / g, crystallization enthalpy of 60.35J / g, breaking strength of 2.93cN / dtex, elongation at break of 38.3%, thermal conductivity at 10℃ of 0.94W / m·K, and volume resistivity of 7.3×10⁻⁶. 13The Ω·cm (significantly increased compared to Example 3, with decreased antistatic properties) indicates a stable fiber structure. The fiber is partially degradable after disposal, with a biodegradation rate of 40.32%. The hygroscopicity (moisture regain) is 7.0% higher than that of conventional polylactic acid filament (the moisture regain of conventional polylactic acid filament is 0.4%).

[0074] As can be seen from Comparative Example 1, the absence of conductive nucleating agent monomers mainly leads to a significant deterioration in the antistatic properties of the fibers, while other properties remain basically stable, proving that conductive nucleating agent monomers (aniline) can effectively improve the antistatic properties of fibers.

[0075] Comparative Example 2 Compared with Example 4, this comparative example does not add thermally conductive nucleating agents (hydroxylated boron nitride nanosheets) in the preparation steps of the composite functional phase change material energy storage and temperature regulation microcapsules and the preparation steps of the fiber-forming polymer matrix material. The remaining preparation steps, raw material types and amounts, and process parameters are exactly the same as in Example 4, and energy storage and temperature regulation polylactic acid filaments with specifications of 132dtex / 78f are prepared.

[0076] The obtained fiber properties were tested and found to be as follows: melting temperature range of 25.2~37.1℃, crystallization temperature range of 14.9~33.1℃, melting enthalpy of 61.41 J / g, crystallization enthalpy of 60.39 J / g, breaking strength of 2.95 cN / dtex, elongation at break of 39.3%, thermal conductivity at 10℃ of 0.51 W / m·K (significantly lower than Example 3, only 53.7% of it), and volume resistivity of 8.8 × 10⁻⁶. 8 The fiber has a stable structure and can be partially degraded after disposal. Its biodegradability is 41.30%, and its moisture regain is 7.1% higher than that of conventional polylactic acid filament (the moisture regain of conventional polylactic acid filament is 0.4%).

[0077] As can be seen from Comparative Example 2, the absence of a thermally conductive nucleating agent mainly leads to a significant decrease in the fiber's thermal conductivity (reduced heat transfer efficiency and worsened temperature regulation performance), while other properties remain basically stable, proving that the thermally conductive nucleating agent (hydroxylated boron nitride nanosheets) can effectively improve the fiber's thermal conductivity.

[0078] Comparative Example 3 Compared with Example 4, this comparative example does not perform plasma etching in the preparation steps of the energy storage and temperature regulation chemical fiber filament. The remaining preparation steps, raw material types and amounts, and process parameters are exactly the same as those in Example 4, and the energy storage and temperature regulation polylactic acid filament with specifications of 132dtex / 78f is prepared.

[0079] The obtained fiber properties were tested and are as follows: melting temperature range of 25.6~37.5℃, crystallization temperature range of 15.6~33.2℃, melting enthalpy of 61.49J / g, crystallization enthalpy of 60.51J / g, breaking strength of 2.96cN / dtex, elongation at break of 38.7%, thermal conductivity at 10℃ of 0.93W / m·K, and volume resistivity of 8.9×10⁻⁶. 8 The fiber structure is stable and can be partially degraded after disposal. The biodegradation rate is 40.35%. The hygroscopicity is basically unchanged compared with conventional polylactic acid filaments (significantly lower than 7.3% in Example 4).

[0080] As can be seen from Comparative Example 3, without plasma etching, the fiber's hygroscopicity is significantly reduced, while other properties remain basically stable. This proves that plasma etching can effectively etch the fiber surface and increase the surface area, thereby improving the fiber's hygroscopicity.

[0081] Comparative Example 4 Compared with Example 4, the bio-based composite phase change material and the fiber-forming polymer matrix material were simply blended (without using a core-sheath composite structure), while the remaining steps and parameters were the same, to prepare energy-storage temperature-regulating polylactic acid filaments.

[0082] That is, the specific step (5) is modified as follows: The bio-based composite phase change material from step (3) and the fiber-forming polymer matrix material from step (4) are dried to a moisture content of 101 ppm (≤500 ppm). Then, the two are physically stirred and mixed evenly. The mixed material is then melt-extruded by a screw. The melt mixture is filtered and degassed before entering a metering pump and then sprayed out through a spinning assembly to form a filament bundle. The filament bundle is cooled by air at 35°C and a ring blower to obtain a nascent fiber with a core-sheath structure. The nascent fiber is then subjected to stretching, shaping, plasma etching, and crimping processes to produce a 132 dtex / 78 f energy storage temperature-regulating polylactic acid filament. Other operations and parameters remain unchanged.

[0083] The prepared energy storage temperature-regulating polylactic acid filaments were tested and found to have the following properties: melting temperature range of 24.9~37.1℃, crystallization temperature range of 10.6~33.2℃, melting enthalpy of 53.32J / g, crystallization enthalpy of 51.91J / g, tensile strength of 2.71cN / dtex, elongation at break of 28.9%, thermal conductivity at 10℃ of 0.89W / m·K, and volume resistivity of 8.7×10⁻⁶. 8 It has a moisture content of Ω·cm, is partially degradable after disposal, has a biodegradation rate of 40.29%, and its hygroscopicity is 7.2% higher than that of conventional polylactic acid filament (the moisture regain rate of conventional polylactic acid filament is 0.4%).

[0084] As can be seen from Comparative Example 4, when the bio-based composite phase change material is blended with the fiber-forming polymer matrix material in a simple manner (without using a core-sheath composite structure), the melting enthalpy, crystallization enthalpy, breaking strength, and breaking elongation of the fiber filament are significantly reduced, while the other properties remain basically stable. This shows that the core-sheath composite structure can prevent the destruction of the effective components in the bio-based composite phase change material during the spinning process, and can also improve the mechanical properties of the fiber filament, avoiding the influence of the blending structure on the mechanical properties of the fiber filament.

[0085] Comparative Example 5 Compared with Example 4, the bio-based composite phase change material in step (5) was replaced with a non-bio-based phase change material (PET), while the other steps and parameters were the same, to prepare energy storage and temperature-regulating polylactic acid filaments.

[0086] The prepared energy storage temperature-regulating polylactic acid filaments were tested and found to have the following properties: melting temperature range of 25.3~37.6℃, crystallization temperature range of 10.2~33.6℃, ​​melting enthalpy of 60.89 J / g, crystallization enthalpy of 60.31 J / g, tensile strength of 2.89 cN / dtex, elongation at break of 38.9%, thermal conductivity at 10℃ of 0.95 W / m·K, and volume resistivity of 8.9 × 10⁻⁶. 8 It has a moisture content of Ω·cm, is partially degradable after disposal, has a biodegradation rate of 28.12%, and its hygroscopicity is 1.2% lower than that of conventional polylactic acid filament (the moisture regain rate of conventional polylactic acid filament is 0.4%).

[0087] As can be seen from Comparative Example 5, replacing the bio-based composite phase change material in step (5) with a non-bio-based phase change material that does not contain poly(3-hydroxybutyrate-3-hydroxyvalerate) and polylactic acid, and replacing it with the fiber-forming polymer matrix material PET, mainly leads to a significant decrease in the biodegradability and hygroscopicity of the fiber filaments, while the other properties remain basically stable. It can be seen that the application of bio-based materials can improve the biodegradability of the fiber filaments and improve their hygroscopicity.

Claims

1. An energy storage and temperature-regulating chemical fiber, characterized in that: The core layer adopts a core-skin composite structure, with the core layer being a bio-based composite phase change material and the skin layer being a fiber-forming polymer matrix material. The bio-based composite phase change material is mainly composed of composite functional phase change material energy storage and temperature regulation microcapsules, polyethylene glycol polymer-based phase change material, poly(3-hydroxybutyrate-3-hydroxyvalerate) and polylactic acid blended and granulated.

2. The energy storage and temperature regulation chemical fiber according to claim 1, characterized in that: The mass ratio of bio-based composite phase change material to fiber-forming polymer matrix material in the fiber is 30~70:70~30.

3. The energy storage and temperature regulation chemical fiber according to claim 1, characterized in that: The microcapsule particle size D90 ≤ 1.392 μm.

4. The energy storage and temperature regulation chemical fiber according to claim 1, characterized in that: The mass ratio of composite functional phase change material energy storage and temperature regulation microcapsules, polyethylene glycol polymer-based phase change material, poly(3-hydroxybutyrate-3-hydroxyvalerate), and polylactic acid is 100:30~50:20~30:10~20.

5. A method for preparing an energy-storing and temperature-regulating chemical fiber as described in any one of claims 1 to 4, characterized in that, Includes the following steps: (1) Preparation of composite functional phase change material energy storage and temperature regulation microcapsule powder: The molten phase change material is mixed evenly with methyl methacrylate, allyl methacrylate, conductive nucleating agent monomer and thermally conductive nucleating agent, and emulsifier, initiator and water are added. The mixture is emulsified and dispersed under the conditions of oxygen isolation, temperature of 40~50℃ and stirring speed of 1800~2500r / min until a stable emulsion with particle size D90≤0.956μm is formed; Then, the temperature is raised to 70-80℃ and the stirring speed is 500-800 r / min to carry out the polymerization reaction. After the reaction is completed, the temperature is lowered and the pH is adjusted to 7-8.5 to obtain composite functional phase change material energy storage and temperature regulation microcapsule powder. (2) Preparation of polyethylene glycol polymer-based phase change material: First, polybutyrolactam or polycaprolactam is added to toluene-2,4-diisocyanate and reacted at 75~85℃. Polyethylene glycol is added and the reaction continues to obtain PEG-modified acylated butyrolactam or caprolactam block copolymer. Then, butyrolactam or caprolactam is heated at 120~135℃ and sodium hydroxide is added. The mixture is then dehydrated under vacuum at 140~150℃ and cooled to obtain a mixed solution of butyrolactam or caprolactam and sodium hydroxide. Finally, the PEG-modified acylated butyrolactam or caprolactam block copolymer is added to the mixed solution of butyrolactam or caprolactam and sodium hydroxide and heated to 170~185℃ to obtain polyethylene glycol polymer-based phase change material. (3) Preparation of bio-based composite phase change material: The microcapsule powder of step (1), the polyethylene glycol polymer-based phase change material of step (2), poly(3-hydroxybutyrate-3-hydroxyvalerate), and polylactic acid are blended, dried, and granulated to obtain the bio-based composite phase change material; (4) Preparation of fiber-forming polymer matrix material: The fiber-forming polymer is mixed with the thermally conductive material, dried and then granulated to obtain the fiber-forming polymer matrix material; (5) Preparation of energy storage and temperature regulation chemical fiber: The bio-based composite phase change material of step (3) and the fiber-forming polymer matrix material of step (4) are used as core material and skin material respectively. They are melt-extruded by screw extrusion, filtered and degassed, and then fused and sprayed into a core-skin composite component to form a filament bundle. After cooling, nascent fibers with a core-skin structure are obtained. The nascent fibers are then processed by stretching, shaping, plasma etching, crimping or twisting to make energy storage and temperature regulation chemical fiber, or the nascent fibers are further processed by stretching, shaping, plasma etching and cutting to make energy storage and temperature regulation short fibers.

6. The method for preparing energy-storing and temperature-regulating chemical fibers according to claim 5, characterized in that: The phase change material in step (1) is one of n-octadecane, n-nonadecane, and n-eicosane; the conductive nucleating agent monomer is aniline; the thermally conductive nucleating agent is hydroxylated boron nitride nanosheets; the emulsifier is one of sodium salt of styrene-maleic anhydride copolymer, Span-80, and sodium dodecyl sulfate; and the initiator is ammonium persulfate, benzoyl peroxide, or azobisisobutyronitrile.

7. The method for preparing energy-storing and temperature-regulating chemical fibers according to claim 6, characterized in that: The mass ratio of phase change material, methyl methacrylate, allyl methacrylate, conductive nucleating agent monomer, thermally conductive nucleating agent, emulsifier, initiator and water in step (1) is 100:50~70:10~30:10~20:2~5:15~30:0.5~2.5:500~800.

8. The method for preparing energy-storing and temperature-regulating chemical fibers according to claim 5, characterized in that: In step (2), the mass percentages of butyrolactam or caprolactam, toluene-2,4-diisocyanate, and polyethylene glycol are 42-30%, 8-5%, and 50-65%, respectively.

9. The method for preparing energy-storing and temperature-regulating chemical fibers according to claim 5, characterized in that: Step (4) The fiber-forming polymer is one of polylactic acid, polyester, and polyamide; the thermally conductive material is hydroxylated boron nitride nanosheets; the mass ratio of the fiber-forming polymer to the thermally conductive material is 100:2~5.

10. The method for preparing energy-storing and temperature-regulating chemical fibers according to claim 5, characterized in that: Step (5) The plasma treatment uses an output power of 160W~260W, an action time of 60~90s, an air reaction gas, and a reaction pressure of 60~90Pa.