Phase change flame-retardant microcapsules for melt spinning and preparation method and application thereof

Abstract

The application relates to the technical field of textile fibers, in particular to phase change flame-retardant microcapsules for melt spinning and a preparation method and application thereof, which comprise a core material and a wall material, the core material comprises a phase change material, and the wall material comprises a copolymer of melamine, an aldehyde compound and an octaaminophenyl POSS derivative; the mass ratio of the melamine and the octaaminophenyl POSS derivative is 6.31:21-39; the octaaminophenyl POSS derivative is prepared from octaaminophenyl POSS and 2-carboxyalkyl phenyl phosphinic acid through an amidation reaction, wherein the alkyl is a linear alkyl with C1-C4. The phase change flame-retardant microcapsules have high heat resistance, high thermal stability and excellent flame-retardant performance, can be adapted to a melt spinning process, and are helpful to the industrialization development of intelligent temperature control flame-retardant textiles.

Description

Technical Field

[0001] This invention relates to the field of textile fiber technology, specifically to a phase change flame retardant microcapsule for melt spinning, its preparation method, and its application. Background Technology

[0002] Phase change materials (PCMs) are temperature-regulating materials that utilize latent heat to store and release heat. PCM microcapsules, through their core-shell encapsulation structure, overcome the shortcomings of traditional PCMs, such as large volume changes and easy leakage, and are widely used in cryogenic energy storage, smart temperature-controlled textiles, and other fields. Among them, PCM fibers prepared by adding PCMs through spinning can achieve smart temperature regulation, but different spinning processes have significantly different requirements for the performance of microcapsules.

[0003] Melt spinning is currently the most environmentally friendly and efficient spinning process, accounting for over 80% of the total synthetic fiber production. However, its processing temperature reaches 150-300℃, and the material must withstand the strong shearing action of a twin-screw extruder. Traditional melamine-formaldehyde (MF)-based phase change microcapsules have poor heat resistance and thermal stability, and are prone to rupture and leakage under high-temperature shearing, leading to a decrease in enthalpy and even loss of temperature regulation function. They are only suitable for low-temperature processing methods such as wet spinning.

[0004] To improve the overall performance of microcapsules, existing technologies have conducted extensive research on wall material modification. For example, Chinese invention patent (authorization announcement number CN117186846B) discloses a high thermal conductivity, high durability, low-temperature phase change microcapsule. It uses polyethylene glycol-modified melamine resin to improve the toughness of the wall material, adds hydrophobic nano-silicon carbide to enhance thermal conductivity, and uses surface silver plating to suppress core material volatilization. However, it is designed for low-temperature scenarios, and the crosslinking density and heat resistance temperature of the wall material still cannot meet the high-temperature requirements of melt spinning above 200°C. Furthermore, it does not introduce flame-retardant components, failing to solve the fire safety problem of textile materials.

[0005] Furthermore, both organic phase change materials and fiber-forming polymers are flammable substances. Current flame-retardant modifications often involve simply adding halogenated or phosphorus-based flame retardants. Halogenated flame retardants produce toxic gases upon combustion, while the addition of phosphorus-based flame retardants often leads to decreased thermal stability and reduced phase change enthalpy of the microcapsules, making it impossible to simultaneously achieve both high-temperature resistance and flame retardancy. In summary, current technologies have not yet developed high-temperature resistant, flame-retardant phase change microcapsules fully compatible with melt spinning processes, thus limiting the industrialization of intelligent temperature-controlled flame-retardant textiles. Summary of the Invention

[0006] To address the aforementioned issues, this invention provides a phase change flame-retardant microcapsule for melt spinning, which combines high heat resistance, high thermal stability, and excellent flame-retardant properties, and is compatible with melt spinning processes, thus contributing to the industrialization of intelligent temperature-controlled flame-retardant textiles.

[0007] The present invention provides a phase change flame retardant microcapsule for melt spinning, comprising a core material and a wall material, wherein the core material comprises a phase change material, and the wall material comprises a copolymer of melamine, an aldehyde compound and an octaaminophenyl POSS (cage-type polysemisiloxane) derivative; wherein the mass ratio of melamine to octaaminophenyl POSS derivative is 6.31:21-39. The octaaminophenyl POSS derivative is prepared by an amidation reaction of octaaminophenyl POSS with 2-carboxyalkylphenylphosphine, wherein the alkyl group is a C1-C4 straight-chain alkyl group.

[0008] Existing phase change microcapsules mostly target only a single performance improvement (such as improving thermal stability only through wall material modification, or simply adding flame retardants physically). They cannot simultaneously meet the high-temperature shear resistance requirements of melt spinning process and excellent flame retardant performance, nor can they take into account high phase change enthalpy and processing adaptability, making it difficult to apply them to the melt-spun fiber field, which accounts for more than 80% of synthetic fibers. This invention uses a copolymer of melamine, aldehyde compounds, and octaaminophenyl POSS derivatives as the wall material, and controls the mass ratio of melamine to octaaminophenyl POSS derivatives (prepared by an amidation reaction of octaaminophenyl POSS and C1-C4 linear alkyl-substituted 2-carboxyalkylphenylphosphinoic acid) to 6.31:21-39. This allows the microcapsules to have an initial decomposition temperature ≥200℃, and maintain an intact core-shell structure even under the high temperature and strong shear of melt spinning at 200-220℃, completely avoiding core material leakage and loss of temperature regulation function. It also significantly improves flame retardant performance through the synergistic effect of phosphorus and silicon. Bio-based nylon fabrics with these microcapsules have a limiting oxygen index of up to 30.6% and a UL94 rating of V0, achieving excellent intelligent temperature regulation effect.

[0009] The rationale for this invention is likely as follows: the rigid cage-like siloxane structure of the octaaminophenyl POSS derivative significantly improves the crosslinking density and mechanical strength of the wall material, effectively resisting high-temperature thermal degradation and twin-screw shear force damage during melt spinning; pre-grafting phosphorus-containing flame-retardant groups onto the POSS molecule via an amidation reaction avoids flame retardant migration and precipitation and microcapsule aggregation and adhesion caused by physical blending, while ensuring the uniform distribution of flame-retardant groups in the wall material; phosphorus catalyzes the formation of a carbon layer in the condensed phase during combustion, while silicon forms a dense silica protective layer on the carbon layer surface to block heat and oxygen transfer, thus jointly constructing a highly efficient phosphorus-silicon synergistic flame-retardant system; and strict control of the reaction between melamine and octaaminophenyl POSS... The optimal range of derivative mass ratio is 6.31:21-39, which ensures the heat resistance and flame retardancy of the wall material, while avoiding the decrease in core material coverage and loss of phase change enthalpy caused by excessive wall material proportion. Ultimately, it achieves synergistic optimization of thermal stability, flame retardancy and energy storage temperature regulation performance, and is fully compatible with melt spinning process requirements.

[0010] In one embodiment, the mass ratio of melamine to octaaminophenyl POSS derivative is 6.31:21.8-38.7.

[0011] In one embodiment, the phase change material includes C 16 -C 18 Straight-chain alkanes and rare earth neodecanoate; wherein, the mass of rare earth neodecanoate is C. 16 -C 18 The rare earth element in neodecanoic acid is selected from at least one of lanthanum, cerium, or yttrium, and consists of 1%-10% of the mass of straight-chain alkanes.

[0012] In one embodiment, the phase change material comprises n-octadecane and lanthanum neodecanoate, wherein the mass of lanthanum neodecanoate is 2.6-3% of the mass of n-octadecane.

[0013] In one embodiment, the aldehyde compound includes at least one of formaldehyde, acetaldehyde, glyoxal, malondialdehyde, and glutaraldehyde.

[0014] In one embodiment, the molar ratio of aldehyde groups to amino groups in the wall material is 1.1-1.2:1.

[0015] In one embodiment, the molar ratio of 2-carboxyalkylphenylphosphine to octaaminophenyl POSS is 2-4:1.

[0016] In one embodiment, the 2-carboxyalkylphenylphosphine includes at least one of 2-carboxymethylphenylphosphine, 2-carboxyethylphenylphosphine (CEPPA), 2-carboxypropylphenylphosphine, or 2-carboxybutylphenylphosphine.

[0017] In one embodiment, the method for preparing the octaaminophenyl POSS derivative includes the following steps: Mix octaaminophenyl POSS with a solvent and stir at 200-300 r / min for 20-30 min. Add 2-carboxyalkylphenylphosphine and raise the system temperature to 80-85℃. React at this temperature for 6-8 h. After the reaction is complete, cool to room temperature (25±2℃), filter the precipitate, wash and dry it to obtain the octaaminophenyl POSS derivative.

[0018] In one embodiment, the solvent comprises ethanol and water in a volume ratio of 75-80:20-25.

[0019] Another aspect of the present invention provides a method for preparing phase change flame retardant microcapsules for melt spinning, comprising the following steps: Aldehyde compounds, melamine, and distilled water are mixed, and an alkaline solution is added to adjust the pH to 8-9. The temperature is raised to 70-80℃, and the mixture is stirred at 350-400 r / min for 40-45 min. Then, an octaaminophenyl POSS derivative is added, and the mixture is ultrasonically dispersed for 10-15 min to obtain a wall material prepolymer solution. A stable suspension emulsion is prepared by mixing phase change material, dispersant, emulsifier and distilled water and then shearing emulsifying it. The wall material prepolymer solution is added to a suspension emulsion at 40-45℃, stirred and mixed, and then an acid solution is added to adjust the pH to 5.5-6. The temperature is raised to 70-75℃ and kept for 1.5-2 hours. Then the temperature is raised to 80-85℃ and kept for 1-1.5 hours to obtain a reaction solution. The reaction solution is post-treated to obtain phase change flame retardant microcapsules for melt spinning.

[0020] In one embodiment, the mass ratio of melamine to distilled water is 60-70:100.

[0021] In one embodiment, the alkaline solution comprises an aqueous solution of triethanolamine with a mass concentration of 10-15%.

[0022] In one embodiment, the mass ratio of the phase change material, dispersant, and emulsifier is 1:0.03-0.05:0.02.

[0023] In one embodiment, the dispersant comprises polystyrene-maleic anhydride sodium salt, and the emulsifier is Boaka polypropylene glycol 2000.

[0024] In one embodiment, the shear emulsification rate is 6000-8000 r / min and the time is 15-25 min.

[0025] In one embodiment, the stirring speed is 6000-8000 r / min and the time is 15-20 min.

[0026] In one embodiment, the acid solution is at least one of glacial acetic acid aqueous solution or citric acid aqueous solution with a mass concentration of 8-10%.

[0027] In one embodiment, the post-treatment includes the following steps: cooling the reaction solution to room temperature, adjusting the pH to 7-7.5 with 15-20 g / L sodium hydroxide solution, solidifying for 10-12 h, filtering, washing with distilled water and ethanol in sequence, and drying at 50-60°C for 10-12 h.

[0028] This invention optimizes the prepolymer preparation process and emulsification polymerization parameters to prepare microcapsules that are regularly spherical, with smooth, defect-free surfaces and uniform particle size distribution (D). 100 <5μm), the microcapsules have excellent dispersibility and will not cause pore blockage during spinning, thus meeting the requirements of subsequent weaving processes.

[0029] This invention uses in-situ polymerization to prepare the product, which has simple process steps, mild reaction conditions (maximum reaction temperature 85℃), no need for complex equipment, and stable and reliable product quality, making it suitable for large-scale industrial production.

[0030] A third aspect of the present invention provides an application of phase change flame retardant microcapsules for melt spinning, applied to the preparation of fibers or fabrics.

[0031] The present invention provides a composite phase change fiber, comprising, by mass percentage, 2-15% phase change flame retardant microcapsules and the balance polymer matrix.

[0032] In one embodiment, the polymer matrix comprises bio-based nylon, the bio-based nylon having a melting point of 180-220°C.

[0033] In one embodiment, the bio-based nylon comprises nylon 6.

[0034] The phase change flame retardant microcapsules prepared by this invention can be widely used in sports and outdoor clothing, home textile products, special protective clothing, automotive interiors and other fields, providing relevant ideas for the industrialization of intelligent temperature-controlled flame retardant textiles.

[0035] Beneficial effects 1. This invention provides a phase change flame retardant microcapsule for melt spinning, which has high heat resistance, high thermal stability and excellent flame retardant properties, and can be adapted to melt spinning process, which is conducive to the industrialization of intelligent temperature-controlled flame retardant textiles.

[0036] 2. This invention uses a copolymer of melamine, aldehyde compounds, and octaaminophenyl POSS derivatives as the wall material, controlling the mass ratio of melamine to octaaminophenyl POSS derivatives (prepared by an amidation reaction of octaaminophenyl POSS and C1-C4 linear alkyl-substituted 2-carboxyalkylphenylphosphinoic acid) to 6.31:21-39. Under the high temperature and strong shear of melt spinning at 200-220℃, the core-shell structure remains intact, completely avoiding core material leakage and loss of temperature regulation function. Furthermore, the synergistic effect of phosphorus and silicon significantly improves flame retardant performance. Bio-based nylon fabrics with these microcapsules achieve a limiting oxygen index of up to 30.6% and a UL94 rating of V0, achieving excellent intelligent temperature regulation.

[0037] 3. By optimizing the prepolymer preparation process and emulsification polymerization parameters, the present invention prepares microcapsules that are regularly spherical, with smooth and defect-free surfaces, uniform particle size distribution (1-5μm), and excellent dispersibility, which will not cause pore blockage during spinning and can meet the requirements of subsequent weaving processes.

[0038] 4. This invention uses in-situ polymerization to prepare the product. The process steps are simple, the reaction conditions are mild (maximum reaction temperature 85℃), no complicated equipment is required, and the product quality is stable and reliable, making it suitable for large-scale industrial production.

[0039] 5. The phase change flame retardant microcapsules prepared by this invention can be widely used in sports and outdoor clothing, home textile products, special protective clothing, automotive interiors and other fields, providing relevant ideas for the industrialization of intelligent temperature-controlled flame retardant textiles. Attached Figure Description

[0040] Figure 1 This is a physical image of the phase change flame retardant microcapsule provided in Example 3.

[0041] Figure 2 The image shows the optical microstructure of the phase change flame retardant microcapsule provided in Example 3.

[0042] Figure 3 Optical micrograph of the phase change flame retardant microcapsule provided for Comparative Example 2.

[0043] Figure 4 Optical micrograph of the phase change flame retardant microcapsule provided for Comparative Example 3.

[0044] Figure 5 The particle size distribution diagram of the phase change flame retardant microcapsules provided in Example 3. Detailed Implementation

[0045] The information of each raw material in this invention is as follows: Melamine: Henan Junhua Development Co., Ltd.; Formaldehyde: Tianjin Tianli Chemical Reagent Co., Ltd.; Octaaminophenyl POSS: Xi'an Qiyue Biotechnology Co., Ltd.; Octaaminopropyl POSS: Xi'an Qiyue Biotechnology Co., Ltd.; CEPPA (2-Carboxyethylphenylphosphonic acid): Wuhan Kabuda Chemical Co., Ltd.; n-Octadecane: Suzhou Senfida Chemical Co., Ltd.; Lanthanum neodecanoate: Guangdong Jianrui New Materials Co., Ltd.; Polystyrene-Sodium Maleic Anhydride: Aladdin Reagent Co., Ltd.; Polypropylene glycol 2000: Shanghai Hongzhuang Chemical Technology Co., Ltd.; Bio-based nylon masterbatch: Anhui Baimai New Material Technology Co., Ltd., spinning grade.

[0046] Example 1 Embodiment 1 of the present invention provides a phase change flame retardant microcapsule for melt spinning, comprising a core material and a wall material, wherein the core material comprises a phase change material, and the wall material comprises a copolymer of melamine, an aldehyde compound and an octaaminophenyl POSS derivative; the mass ratio of melamine to octaaminophenyl POSS derivative is 6.31:25.8. The octaaminophenyl POSS derivative is prepared by an amidation reaction of octaaminophenyl POSS with 2-carboxyalkylphenylphosphine.

[0047] The phase change material comprises n-octadecane and lanthanum neodecanoate in a mass ratio of 26.28:0.674.

[0048] The aldehyde compound is formaldehyde. The mass ratio of melamine to formaldehyde is 6.31:8.32.

[0049] The molar ratio of 2-carboxyalkylphenylphosphine to octaaminophenyl POSS is 2:1.

[0050] The 2-carboxyalkylphenylphosphine is 2-carboxyethylphenylphosphine (CEPPA).

[0051] The preparation method of the octaaminophenyl POSS derivative includes the following steps: Octaaminophenyl POSS was mixed with a solvent and stirred at 200 rpm for 30 min. 2-Carboxyalkylphenylphosphine was added, and the system temperature was raised to 84 °C. The reaction was maintained at this temperature for 7 h. After the reaction was complete, the mixture was cooled to room temperature (25 ± 2 °C), the precipitate was filtered, washed with ethanol, and dried under vacuum at 50 °C to obtain the octaaminophenyl POSS derivative. The solvent consisted of ethanol and water in a volume ratio of 75:25.

[0052] Example 1 of the present invention provides a method for preparing phase change flame retardant microcapsules for melt spinning, comprising the following steps: Aldehyde compounds, melamine, and distilled water were mixed, and an alkaline solution was added to adjust the pH to 8. The temperature was raised to 70°C, and the mixture was stirred at 350 r / min for 45 min. Then, an octaaminophenyl POSS derivative was added, and the mixture was ultrasonically dispersed for 10 min to obtain a wall material prepolymer solution. A stable suspension emulsion is prepared by mixing phase change material, dispersant, emulsifier and distilled water and then shearing emulsifying it. The wall material prepolymer solution was added to a suspension emulsion at 45°C, stirred and mixed, and then an acid solution was added to adjust the pH to 5.5. The temperature was raised to 75°C and kept for 1.5 hours. Then the temperature was raised to 80°C and kept for reaction 1 to obtain the reaction solution. The reaction solution was post-treated to obtain phase change flame retardant microcapsules for melt spinning.

[0053] The mass ratio of melamine to distilled water is 6.31 g: 95.0 mL.

[0054] The alkaline solution comprises a 10% aqueous solution of triethanolamine.

[0055] The mass ratio of the phase change material, dispersant, and emulsifier is 26.954:1.078:0.539.

[0056] The dispersant includes polystyrene-maleic anhydride sodium salt, and the emulsifier is Boaka polypropylene glycol 2000.

[0057] The shear emulsification rate was 8000 r / min, and the time was 20 min.

[0058] The stirring speed is 6000 r / min and the time is 20 min.

[0059] The acid solution is a 10% aqueous solution of glacial acetic acid.

[0060] The post-treatment includes the following steps: the reaction solution is cooled to room temperature, the pH is adjusted to 7 with 20 g / L sodium hydroxide solution, solidified for 12 h, filtered, washed successively with distilled water and ethanol, and dried at 50 °C for 12 h.

[0061] Example 2 Example 2 of the present invention provides a phase change flame retardant microcapsule for melt spinning and its preparation method. The specific implementation method is the same as that of Example 1, except that the mass ratio of melamine to octaaminophenyl POSS derivative is 6.31:32.3; the mass ratio of melamine to formaldehyde is 6.31:7.21; the molar ratio of 2-carboxyalkylphenylphosphine to octaaminophenyl POSS is 4:1; the solvent includes ethanol and water in a volume ratio of 80:20; the phase change material includes n-octadecane and lanthanum neodecanoate in a mass ratio of 29.78:0.764; and the mass ratio of phase change material, dispersant, and emulsifier is 30.544:1.527:0.611.

[0062] Example 3 Example 3 of this invention provides a phase change flame retardant microcapsule for melt spinning and its preparation method. The specific implementation is the same as in Example 1, except that the mass ratio of melamine to octaaminophenyl POSS derivative is 6.31:33.1; the mass ratio of melamine to formaldehyde is 6.31:8.11; the molar ratio of 2-carboxyalkylphenylphosphine to octaaminophenyl POSS is 3:1; the solvent includes ethanol and water in a volume ratio of 80:20; the phase change material includes n-octadecane and lanthanum neodecanoate in a mass ratio of 28.23:0.724; and the mass ratio of the phase change material, dispersant, and emulsifier is 28.954:1.158:0.579. The prepared phase change flame retardant microcapsule for melt spinning is described in [reference needed]. Figure 1 .

[0063] Example 4 Example 4 of the present invention provides a phase change flame retardant microcapsule for melt spinning and its preparation method. The specific implementation method is the same as that of Example 1, except that the mass ratio of melamine to octaaminophenyl POSS derivative is 6.31:38.7; the mass ratio of melamine to formaldehyde is 6.31:9.91; the phase change material includes n-octadecane and lanthanum neodecanoate in a mass ratio of 35.70:0.915; and the mass ratio of phase change material, dispersant, and emulsifier is 36.615:1.831:0.732.

[0064] Example 5 Example 5 of the present invention provides a phase change flame retardant microcapsule for melt spinning and its preparation method. The specific implementation method is the same as that of Example 3, except that the mass ratio of melamine to octaaminophenyl POSS derivative is 6.31:21.8; the mass ratio of melamine to formaldehyde is 6.31:7.12; the molar ratio of 2-carboxyalkylphenylphosphine to octaaminophenyl POSS is 3:1; the solvent includes ethanol and water in a volume ratio of 80:20; the phase change material includes n-octadecane and lanthanum neodecanoate in a mass ratio of 22.90:0.587; and the mass ratio of phase change material, dispersant, and emulsifier is 23.487:0.94:0.47.

[0065] Comparative Example 1 Comparative Example 1 of the present invention provides a phase change flame retardant microcapsule, the preparation method of which includes the following steps: 6.31 g of melamine, 13.37 g of formaldehyde aqueous solution (mass concentration of 37.02%) and 80.6 ml of distilled water were added to a three-necked flask. The pH was adjusted to 8 with 10 wt% triethanolamine aqueous solution. The temperature was raised to 70 °C and the mixture was stirred at 350 r / min for 45 min. After the reaction was completed, the wall material prepolymer solution was obtained.

[0066] Add 22.90g of n-octadecane, 0.587g of lanthanum neodecanoate, and 100ml of distilled water to a beaker, then add 0.73g of polystyrene-maleic anhydride sodium salt and 0.29g of polypropylene glycol 2000. Place the beaker in a 45℃ water bath and emulsify for 20 minutes at 8000r / min using a high-speed shear emulsifier to obtain a suspension emulsion.

[0067] The suspension emulsion was added to a three-necked flask placed in a 45°C water bath. The wall material prepolymer solution was then slowly added to the suspension emulsion. The mixture was stirred at 4000 rpm for 15 min, and the stirring speed was adjusted to 450 rpm. An acid solution (10 wt% glacial acetic acid aqueous solution) was added to the mixed emulsion to adjust the pH to 5.5. The temperature was then raised to 75°C and held for 1.5 h, followed by a further increase to 80°C and a holding time of 1 h. After cooling to room temperature, the pH was adjusted to neutral with a 20 wt% sodium hydroxide solution. After solidification for 12 h, the precipitate was filtered, washed, and dried at 50°C for 12 h to obtain phase change flame retardant microcapsules.

[0068] Comparative Example 2 Comparative Example 2 of the present invention provides a phase change flame retardant microcapsule and its preparation method. The specific implementation method is the same as that of Example 3, except that in the preparation method of the phase change flame retardant microcapsule: aldehyde compound, melamine and distilled water are mixed evenly, an octaaminophenyl POSS derivative is added, an alkaline solution is added to adjust the pH to 8, the temperature is raised to 70°C, and the reaction is stirred at 350 r / min for 45 min until the solution is semi-transparent. The solution is then ultrasonically dispersed for 10 min to obtain a wall material prepolymer solution.

[0069] Comparative Example 3 Comparative Example 3 of the present invention provides a phase change flame retardant microcapsule and its preparation method, the specific implementation of which is the same as Example 3, except that the wall material includes melamine, formaldehyde aqueous solution (mass concentration of 37.02%), CEPPA aqueous solution (solution pH=7), and octaaminophenyl POSS. The mass ratio of melamine, formaldehyde aqueous solution, and octaaminophenyl POSS is 6.31:21.9:21.9; the molar ratio of CEPPA to octaaminophenyl POSS in the CEPPA aqueous solution is 3:1. In the preparation method of the phase change flame retardant microcapsule, the wall material prepolymer solution is prepared through the following steps: Formaldehyde aqueous solution, melamine, and distilled water were mixed, and an alkaline solution was added to adjust the pH to 8. The temperature was raised to 70°C, and the mixture was stirred at 350 r / min for 45 min. CEPPA aqueous solution (solution pH=7) and octaaminophenyl POSS were added, and the mixture was ultrasonically dispersed for 10 min to obtain the wall material prepolymer solution.

[0070] Comparative Example 4 Comparative Example 4 of the present invention provides a phase change flame retardant microcapsule and its preparation method. The specific implementation method is the same as that of Example 3, except that octaaminophenyl POSS is replaced with octaaminopropyl POSS to prepare octaaminopropyl POSS derivative, and octaaminopropyl POSS derivative is used to replace octaaminophenyl POSS derivative.

[0071] Performance testing 1. The phase change flame retardant microcapsules prepared in Examples 1-5 and Comparative Examples 1-4 were subjected to DSC and TG tests. The DSC test measured the thermal properties of the microcapsule powder under nitrogen protection during heating and cooling processes. The heating / cooling temperature range was 10–80 °C, and the heating / cooling rate was 5 °C / min. The TG test was conducted on the microcapsule powder under nitrogen protection, with a test temperature range of 20–550 °C and a heating rate of 10 °C / min. The test results are shown in Table 1.

[0072] Table 1

[0073] As shown in Table 1, the microcapsule powders prepared in Examples 1-5 and Comparative Examples 1-4 all have a phase transition enthalpy greater than 130 J / g, exhibiting good energy storage performance. Furthermore, the microcapsule powders in Examples 1-4 have high initial decomposition temperatures of the wall material, all exceeding 200℃, demonstrating good thermal stability. In contrast, the microcapsules prepared in Example 5 used a lower amount of the octaaminophenyl POSS derivative, limiting its effect on increasing the initial decomposition temperature of the capsule wall material, but still exceeding that of the unmodified MF microcapsules in Comparative Example 1. The microcapsule powders prepared in Comparative Example 2 contain... The wall material surface showed obvious cracks, and the initial decomposition temperature of the microcapsule wall material was lower than that of the microcapsules prepared in Comparative Example 1. The reason is speculated to be that the wall material prepolymer was not completely coated or the wall was too thin and broke under mechanical force, which led to a decrease in the thermal stability of the microcapsule powder and made it unsuitable for melt spinning. The microcapsules prepared in Comparative Example 3 showed severe adhesion, and the agglomerates were difficult to open, resulting in excessively large powder particle size, which easily caused pore blockage and made it unsuitable for melt spinning. The thermal stability improvement effect of using octaaminopropyl POSS derivative in Comparative Example 4 was slightly poor.

[0074] 2. Bio-based nylon F1058 was mixed with the phase change flame-retardant microcapsules of Examples 1-4 at a mass ratio of 92:8. The mixture was then added to a spinning machine. The extrusion temperatures were set as follows: Zone 1: 195°C, Zone 2: 200°C, Zone 3: 215°C, Zone 4: 210°C. The spinning pump temperature was 205°C for melt spinning to obtain composite phase change fibers. The fibers were then woven into fabric for flame retardant performance testing. The testing standards were: Limiting Oxygen Index (LOI), according to GB / T5454-1997; UL-94 Vertical Burning Test, according to GB / T5455-1997. The test results are shown in Table 2.

[0075] Table 2

[0076] As shown in Table 2, the oxygen index of the fabrics with added microcapsules from Examples 1-4 is above 28.5%, and all of them can reach the UL-94 vertical burning test level V1 or above. In particular, Example 2 has an oxygen index of 30.6% and a UL94 level of V0, which proves that the product system of the present invention can ensure the flame retardant performance of the fabric through the synergistic flame retardant effect of phosphorus and silicon.

[0077] 3. The phase change flame retardant microcapsules provided in Example 3, Comparative Example 2, and Comparative Example 3 were observed using optical microscopy. The results are shown in [reference needed]. Figure 2-4The microcapsules prepared in Example 3 were regularly spherical with a distinct core-shell structure and good dispersibility. The microcapsules prepared in Comparative Example 2 were also regularly spherical with good dispersibility, but the capsule wall surface was damaged. The microcapsules prepared in Comparative Example 3 showed flocculent adhesion between them, with the adhesion being more pronounced as the particle size decreased. Therefore, Example 3 of this application, through exploring the wall material preparation process and optimizing the selection of POSS, effectively solved the problems of insufficient thermal stability caused by poor encapsulation of the prepolymer on the core material surface and severe adhesion between microcapsules affecting the spinning application of the capsules. The prepared microcapsules exhibited excellent thermal stability and dispersibility (see...). Figure 2 This improves compatibility with melt spinning technology.

Claims

1. A phase change flame retardant microcapsule for melt spinning, characterized in that, The product includes a core material and a wall material. The core material includes a phase change material, and the wall material includes a copolymer of melamine, an aldehyde compound, and an octaaminophenyl POSS derivative. The mass ratio of the melamine to the octaaminophenyl POSS derivative is 6.31:21-39. The octaaminophenyl POSS derivative is prepared by an amidation reaction of octaaminophenyl POSS with 2-carboxyalkylphenylphosphine, wherein the alkyl group is a C1-C4 straight-chain alkyl group; the phase change material includes C 16 -C 18 Straight-chain alkanes and rare earth neodecanoate; wherein, the mass of rare earth neodecanoate is C. 16 -C 18 The linear alkane comprises 1%-10% by mass, and the rare earth element in the neodecanoic acid is selected from at least one of lanthanum, cerium, or yttrium; the molar ratio of the 2-carboxyalkylphenylphosphine to octaaminophenyl POSS is 2-4:

1.

2. The phase change flame retardant microcapsule according to claim 1, characterized in that, The phase change material comprises n-octadecane and lanthanum neodecanoate, wherein the mass of lanthanum neodecanoate is 2.6-3% of the mass of n-octadecane.

3. The phase change flame retardant microcapsule according to claim 1, characterized in that, The aldehyde compounds include at least one of formaldehyde, acetaldehyde, glyoxal, malondialdehyde, and glutaraldehyde.

4. The phase change flame retardant microcapsule according to claim 1, characterized in that, The molar ratio of aldehyde groups to amino groups in the wall material is 1.1-1.2:

1.

5. The phase change flame retardant microcapsule according to claim 1, characterized in that, The 2-carboxyalkylphenylphosphine includes at least one of 2-carboxymethylphenylphosphine, 2-carboxyethylphenylphosphine, 2-carboxypropylphenylphosphine, or 2-carboxybutylphenylphosphine.

6. The phase change flame retardant microcapsule according to claim 1, characterized in that, The preparation method of the octaaminophenyl POSS derivative includes the following steps: Mix octaaminophenyl POSS with a solvent and stir at 200-300 r / min for 20-30 min. Add 2-carboxyalkylphenylphosphine and raise the system temperature to 80-85℃. React at this temperature for 6-8 h. After the reaction is complete, cool to room temperature, filter the precipitate, wash, and dry to obtain the octaaminophenyl POSS derivative.

7. The phase change flame retardant microcapsule according to claim 6, characterized in that, The solvent comprises ethanol and water in a volume ratio of 75-80:20-25.

8. A method for preparing phase change flame retardant microcapsules according to any one of claims 1-7, characterized in that, Includes the following steps: Aldehyde compounds, melamine, and distilled water are mixed, and an alkaline solution is added to adjust the pH to 8-9. The temperature is raised to 70-80℃, and the mixture is stirred at 350-400 r / min for 40-45 min. Then, an octaaminophenyl POSS derivative is added, and the mixture is ultrasonically dispersed for 10-15 min to obtain a wall material prepolymer solution. A stable suspension emulsion is prepared by mixing phase change material, dispersant, emulsifier and distilled water and then shearing emulsifying it. The wall material prepolymer solution is added to a suspension emulsion at 40-45℃, stirred and mixed, and then an acid solution is added to adjust the pH to 5.5-6. The temperature is raised to 70-75℃ and kept for 1.5-2 hours. Then the temperature is raised to 80-85℃ and kept for 1-1.5 hours to obtain a reaction solution. The reaction solution is post-treated to obtain phase change flame retardant microcapsules for melt spinning.

9. The method for preparing phase change flame retardant microcapsules according to claim 8, characterized in that, The mass ratio of the phase change material, dispersant, and emulsifier is 1:0.03-0.05:0.

02.

10. An application of the phase change flame retardant microcapsule according to any one of claims 1-7, characterized in that, It is used in the preparation of fibers or fabrics.

Images