A gas-liquid phase change material, method and application based on synthetic mineral oil

Abstract

This invention provides a gas-liquid phase change material based on synthetic mineral oil, a method for its application, and its composition by weight: 40-60 parts synthetic mineral oil, 5-15 parts modifier, 3-10 parts phase change regulator, 1-5 parts antioxidant, and 2-8 parts stabilizer. The method includes weighing the raw materials according to the specified weight proportions; adding the synthetic mineral oil to a reaction vessel and stirring to homogenize the oil phase; sequentially adding the modifier and phase change regulator to the reaction vessel to achieve thorough grafting and mixing of the components; cooling to 50-60°C, adding the antioxidant and stabilizer, and continuing stirring for 20-40 minutes; after stirring, filtering with a filtration precision of 0.1-0.5 μm to remove impurities, thereby obtaining the gas-liquid phase change material based on synthetic mineral oil. The invention also includes applications of this gas-liquid phase change material in energy storage systems, temperature control devices, or cold chain transportation. This phase change material exhibits excellent phase change performance, good chemical stability, long cycle life, and a simple and cost-effective preparation process.

Description

Technical Field

[0001] This invention belongs to the field of phase change materials technology, specifically relating to a gas-liquid phase change material, method, and application based on synthetic mineral oil. Background Technology

[0002] Phase change materials (PCMs) are materials that can absorb or release a large amount of latent heat through a phase change process within a specific temperature range. Due to their excellent energy storage and temperature control properties, they are widely used in various fields such as new energy storage, building energy conservation, electronic device heat dissipation, and cold chain transportation. Among them, gas-liquid PCMs have become one of the research hotspots in the field of PCMs because of their large latent heat of phase change and mild phase change process.

[0003] Currently, most existing gas-liquid phase change materials are based on natural mineral oils, vegetable oils, or synthetic polymers. Natural mineral oils are widely available and inexpensive, but they suffer from poor chemical stability, a narrow phase change temperature range, and are prone to oxidative degradation during recycling. Vegetable oils, while environmentally friendly, have high viscosity and low heat transfer efficiency during phase change. Synthetic polymers have excellent latent heat of phase change, but their complex preparation processes and high costs limit their large-scale application.

[0004] Synthetic mineral oil, a mineral oil substitute prepared through chemical synthesis, possesses advantages such as good chemical stability, moderate viscosity, and excellent antioxidant properties. Using it as a base material for gas-liquid phase change materials (GLCs) holds promise for overcoming many shortcomings of existing GLCs. However, the phase change temperature and latent heat of pure synthetic mineral oil are insufficient to meet the requirements of various applications, necessitating optimization and control through the addition of suitable modifiers and phase change regulators. Therefore, developing a GLC based on synthetic mineral oil, through rational component ratios and preparation processes, to obtain materials with excellent phase change performance, good stability, and controllable cost is of significant practical importance. Summary of the Invention

[0005] This invention provides a gas-liquid phase change material, method, and application based on synthetic mineral oil. The phase change material has excellent phase change performance, good chemical stability, long cycle life, and simple preparation process with controllable cost.

[0006] According to a first aspect of the present invention, one or more embodiments of this application provide a gas-liquid phase change material based on synthetic mineral oil, comprising the following raw materials in parts by weight: 40-60 parts synthetic mineral oil, 5-15 parts modifier, 3-10 parts phase change modifier, 1-5 parts antioxidant, and 2-8 parts stabilizer.

[0007] According to the above-described technical solution of the present invention, the following improvements can also be made: Preferably, the synthetic mineral oil is one or more of polyalphaolefin synthetic oil, alkylnaphthalene synthetic oil, and ester synthetic oil; the number average molecular weight of the polyalphaolefin synthetic oil is 200-800.

[0008] Preferably, the modifier is one or both of organosilane coupling agents and maleic anhydride graft polymers; the organosilane coupling agent is one of γ-aminopropyltriethoxysilane and γ-methacryloyloxypropyltrimethoxysilane.

[0009] Preferably, the phase change modifier is one or more of n-octadecane, n-eicosane, and polyethylene glycol, wherein the polyethylene glycol has a molecular weight of 400-1000.

[0010] Preferably, the antioxidant is one or two of hindered phenolic antioxidants and phosphite antioxidants; the hindered phenolic antioxidant is one of 2,6-di-tert-butyl-p-cresol and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid].

[0011] Preferably, the stabilizer is a compound of metal passivating agent and anti-settling agent.

[0012] Preferably, the metal passivating agent is a benzotriazole derivative, and the anti-settling agent is fumed silica, with a weight ratio of 1:1 to 3:1.

[0013] According to a second aspect of the present invention, a method for preparing a gas-liquid phase change material based on synthetic mineral oil is provided, comprising the following steps: S1: Weigh out the synthetic mineral oil, modifier, phase change modifier, antioxidant, and stabilizer according to the specified weight parts, and set aside. S2: Add synthetic mineral oil to the reactor, heat to 60-80℃, stir at 200-400r / min for 10-20min to make the oil phase uniform; S3: Add the modifier and phase change regulator to the reactor in sequence, heat to 90-110℃, keep warm and stir for 30-60 minutes to achieve full grafting and mixing of components; S4: Cool to 50-60℃, add antioxidants and stabilizers, and continue stirring for 20-40 minutes; S5: After stirring, filter the mixture with a filtration accuracy of 0.1-0.5μm to remove impurities and obtain a gas-liquid phase change material based on synthetic mineral oil.

[0014] According to the above-described technical solution of the present invention, the following improvements can also be made; Preferably, nitrogen gas is introduced for protection during the heat preservation and stirring process in step S3, with a nitrogen flow rate of 0.5-1.5 L / min.

[0015] According to a third aspect of the present invention, an application of a gas-liquid phase change material based on synthetic mineral oil in energy storage systems, temperature control devices, or cold chain transportation is provided.

[0016] The beneficial effects of this invention are: This invention provides a gas-liquid phase change material, method, and application based on synthetic mineral oil, compared with the prior art: 1. This invention uses synthetic mineral oil as the base material and combines the synergistic effect of modifiers, phase change regulators and other components to prepare a gas-liquid phase change material with a suitable phase change temperature (-20℃~80℃), which can meet the needs of different application scenarios such as energy storage systems, temperature control devices, and cold chain transportation; at the same time, the latent heat of phase change is ≥180J / g, and the energy storage performance is excellent.

[0017] 2. By adding antioxidants and stabilizers, this invention significantly improves the chemical stability and cycle life of phase change materials. After 1000 phase change cycles, the latent heat decay rate of phase change is ≤5%, enabling long-term stable use.

[0018] 3. The preparation process of this invention is simple, requiring no complex equipment or harsh reaction conditions, and the raw material cost is controllable, making it easy to achieve large-scale production. It has extremely high practical value and promising prospects for promotion. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the preparation process according to an embodiment of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0021] It should be noted that, unless otherwise defined, the technical or scientific terms used in one or more embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms "first," "second," and similar terms used in one or more embodiments of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0022] like Figure 1As shown, one or more embodiments of this application provide a gas-liquid phase change material, method and application based on synthetic mineral oil. The material is composed of the following raw materials in parts by weight: 40-60 parts synthetic mineral oil, 5-15 parts modifier, 3-10 parts phase change modifier, 1-5 parts antioxidant and 2-8 parts stabilizer.

[0023] In this embodiment, the synthetic mineral oil is one or more of polyalphaolefin synthetic oil, alkylnaphthalene synthetic oil, and ester synthetic oil; the number average molecular weight of the polyalphaolefin synthetic oil is 200-800. This type of synthetic mineral oil is chosen as the base raw material because it has excellent chemical stability, low pour point, and high viscosity index, which can provide good basic properties for phase change materials; controlling the number average molecular weight within the range of 200-800 ensures that the synthetic mineral oil has suitable fluidity and phase change characteristics, avoiding excessively high viscosity due to excessively large molecular weight, which would affect the heat transfer efficiency during the phase change process, or insufficient latent heat of phase change due to excessively small molecular weight.

[0024] It is understood that the modifier is one or both of organosilane coupling agents and maleic anhydride graft polymers; the organosilane coupling agent is one of γ-aminopropyltriethoxysilane and γ-methacryloyloxypropyltrimethoxysilane. The modifier's function is to improve the compatibility of synthetic mineral oil with other components, promote the interaction between components, and improve the interfacial stability of the phase change material; the organosilane coupling agent contains active groups such as amino and methacryloyloxy groups, which can undergo grafting reactions with synthetic mineral oil and phase change modifiers, enhancing the binding force between components; the maleic anhydride graft polymer has good polarity, which can further improve the compatibility of each component and prevent the phase change material from stratifying during long-term use.

[0025] It is understood that the phase change modifier is one or more of n-octadecane, n-eicosane, and polyethylene glycol, wherein the molecular weight of polyethylene glycol is 400-1000. The core function of the phase change modifier is to regulate the phase change temperature and latent heat of phase change of the phase change material to meet the needs of different application scenarios. The phase change temperature of n-octadecane is about 28°C, that of n-eicosane is about 36°C, and the phase change temperature of polyethylene glycol (molecular weight 400-1000) is in the range of 40-60°C. By compounding different types and proportions, the phase change temperature of the phase change material can be controlled between -20°C and 80°C. At the same time, these phase change modifiers themselves have high latent heat of phase change and can synergistically work with synthetic mineral oil to improve the latent heat of phase change of the entire phase change material system.

[0026] It is understood that the antioxidant is one or both of hindered phenolic antioxidants and phosphite antioxidants; the hindered phenolic antioxidant is one of 2,6-di-tert-butyl-p-cresol and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]. Antioxidants can inhibit the oxidative degradation of phase change materials during high-temperature phase change and long-term use, extending the service life of the phase change materials; hindered phenolic antioxidants terminate the oxidation chain reaction by providing hydrogen atoms, while phosphite antioxidants can decompose hydrogen peroxides. When used in combination, they can produce a synergistic antioxidant effect, further enhancing antioxidant performance.

[0027] It is understood that the stabilizer is a compound of a metal passivator and an anti-settling agent. The metal passivator is a benzotriazole derivative, and the anti-settling agent is fumed silica, with a weight ratio of 1:1 to 3:1. The metal passivator can form stable complexes with trace metal ions (such as iron and copper ions) that may be present in the phase change material, preventing the metal ions from catalyzing the oxidative degradation of the phase change material; the anti-settling agent, fumed silica, has a large specific surface area and good dispersibility, and can form a three-dimensional network structure in the phase change material system, preventing the components from settling and stratifying during storage and use, thus ensuring the stability of the phase change material's performance.

[0028] The preparation method of the above material includes the following steps: S1: Weigh out the synthetic mineral oil, modifier, phase change modifier, antioxidant, and stabilizer according to the specified weight proportions, and set aside. Accurate raw material ratio is the basis for ensuring the performance of phase change materials, so high-precision weighing equipment must be used for weighing.

[0029] S2: Add the synthetic mineral oil to the reactor, heat it to 60-80℃, stir at a speed of 200-400 r / min for 10-20 min to make the oil phase uniform; this temperature range can keep the synthetic mineral oil in good fluidity, which is convenient for the addition and mixing of subsequent components. The control of stirring speed and time can ensure that the synthetic mineral oil is fully dispersed and avoid local uneven concentration.

[0030] S3: Add the modifier and phase change regulator sequentially to the reactor, heat to 90-110℃, and stir for 30-60 minutes to achieve full grafting and mixing of components; heating to 90-110℃ can activate the active groups in the modifier, promoting its grafting reaction with synthetic mineral oil and phase change regulator. Sufficient stirring time ensures the reaction proceeds fully and enhances the binding force between components; preferably, nitrogen gas is introduced for protection during this process, with a nitrogen flow rate of 0.5-1.5 L / min. Nitrogen protection can prevent oxygen in the air from participating in the reaction, prevent the oxidation of raw materials, and further improve the performance stability of the phase change material.

[0031] S4: Cool to 50-60℃, add antioxidants and stabilizers, and continue stirring for 20-40 minutes; adding antioxidants and stabilizers after cooling can prevent the antioxidants from decomposing and becoming ineffective due to high temperature. This temperature range can still ensure that the components have good fluidity and are easy to mix thoroughly.

[0032] S5: After stirring, filter (filtration accuracy is 0.1-0.5μm) to remove impurities and obtain gas-liquid phase change material based on synthetic mineral oil synthesis; the filtration step can remove trace impurities that may exist in the raw materials and a small amount of by-products generated during the reaction, ensuring the purity of the phase change material and thus improving its performance stability.

[0033] To more clearly explain the technical solutions of the above embodiments, the following implementation methods are provided as examples: Example 1 A gas-liquid phase change material based on synthetic mineral oil is composed of the following raw materials in parts by weight: 40 parts of polyalphaolefin synthetic oil (number average molecular weight 400), 5 parts of γ-aminopropyltriethoxysilane, 3 parts of n-octadecane, 1 part of 2,6-di-tert-butyl-p-cresol, and 2 parts of a compound of benzotriazole derivative and fumed silica (weight ratio 1:1).

[0034] Preparation method: S1: Weigh each raw material according to the above-mentioned weight proportions and set aside; S2: Add the polyα-olefin synthetic oil to the reactor, heat it to 60℃, stir at 200r / min, and stir for 20min to make the oil phase uniform; S3: Add γ-aminopropyltriethoxysilane and n-octadecane sequentially to the reactor, heat to 90°C, purge with nitrogen (nitrogen flow rate 0.5 L / min), and maintain the temperature while stirring for 60 min; S4: Cool to 50℃, add the complex of 2,6-di-tert-butyl-p-cresol and benzotriazole derivative with fumed silica, and continue stirring for 40 min; S5: After stirring, filter through a 0.1μm filter to remove impurities and obtain a gas-liquid phase change material.

[0035] Example 2 A gas-liquid phase change material based on synthetic mineral oil is composed of the following raw materials in parts by weight: 50 parts of a mixture of alkyl naphthalene synthetic oil and ester synthetic oil (weight ratio 1:1), 10 parts of maleic anhydride graft polymer, 6 parts of a mixture of n-eicosane and polyethylene glycol (molecular weight 600) as a modifier (weight ratio 2:1), 3 parts of a compound antioxidant of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and phosphite ester (weight ratio 1:1), and 5 parts of a compound of benzotriazole derivative and fumed silica (weight ratio 2:1).

[0036] Preparation method: S1: Weigh each raw material according to the above-mentioned weight proportions and set aside; S2: Add the mixed synthetic mineral oil to the reactor, heat to 70°C, stir at 300 r / min for 15 min to make the oil phase uniform; S3: Add maleic anhydride grafted polymer and mixed phase change modifier to the reactor in sequence, heat to 100°C, purge with nitrogen (nitrogen flow rate 1.0 L / min), and keep warm while stirring for 45 min; S4: Cool to 55℃, add compound antioxidant and compound stabilizer, and continue stirring for 30 minutes; S5: After stirring, filter through a 0.3μm filter to remove impurities and obtain a gas-liquid phase change material.

[0037] Example 3 A gas-liquid phase change material based on synthetic mineral oil is composed of the following raw materials in parts by weight: 60 parts of polyalphaolefin synthetic oil (number average molecular weight 800), 15 parts of γ-methacryloyloxypropyltrimethoxysilane, 10 parts of polyethylene glycol (molecular weight 1000), 5 parts of phosphite, and 8 parts of a compound of benzotriazole derivative and fumed silica (weight ratio 3:1).

[0038] Preparation method: S1: Weigh each raw material according to the above-mentioned weight proportions and set aside; S2: Add the polyα-olefin synthetic oil to the reactor, heat it to 80℃, stir at 400r / min, and stir for 10min to make the oil phase uniform; S3: Add γ-methacryloxypropyltrimethoxysilane and polyethylene glycol sequentially to the reactor, heat to 110°C, purge with nitrogen (nitrogen flow rate 1.5 L / min), and keep warm while stirring for 30 min; S4: Cool to 60℃, add phosphite and compound stabilizer, and continue stirring for 20 minutes; S5: After stirring, filter through a 0.5μm filter to remove impurities and obtain a gas-liquid phase change material.

[0039] Performance testing: The phase transition temperature, latent heat of phase transition, and cycle stability of the gas-liquid phase change materials prepared in Examples 1-3 were tested. The test results are shown in Table 1. Table 1 Performance test results of gas-liquid phase change materials in Examples 1-3 The test results show that the gas-liquid phase change material prepared by this invention has a suitable phase change temperature, excellent latent heat of phase change and good cycle stability, which meets the usage requirements of different application scenarios.

[0040] The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the present invention. Without departing from the core principles of the present invention, appropriate adjustments can be made to process parameters, raw material ratios, etc., and such adjustments should be considered to be within the protection scope of the present invention.

[0041] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0042] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A gas-liquid phase change material based on synthetic mineral oil, characterized in that, It is composed of the following raw materials in parts by weight: 40-60 parts synthetic mineral oil, 5-15 parts modifier, 3-10 parts phase change modifier, 1-5 parts antioxidant, and 2-8 parts stabilizer.

2. The gas-liquid phase change material based on synthetic mineral oil according to claim 1, characterized in that, The synthetic mineral oil is one or more of polyalphaolefin synthetic oil, alkylnaphthalene synthetic oil, and ester synthetic oil; the number average molecular weight of the polyalphaolefin synthetic oil is 200-800.

3. The gas-liquid phase change material based on synthetic mineral oil according to claim 1, characterized in that, The modifier is one or both of organosilane coupling agents and maleic anhydride graft polymers; the organosilane coupling agent is one of γ-aminopropyltriethoxysilane and γ-methacryloyloxypropyltrimethoxysilane.

4. The gas-liquid phase change material based on synthetic mineral oil according to claim 1, characterized in that, The phase change modifier is one or more of n-octadecane, n-eicosane, and polyethylene glycol, wherein the polyethylene glycol has a molecular weight of 400-1000.

5. The gas-liquid phase change material based on synthetic mineral oil according to claim 1, characterized in that, The antioxidant is one or two of hindered phenolic antioxidants and phosphite antioxidants; the hindered phenolic antioxidant is one of 2,6-di-tert-butyl-p-cresol and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid].

6. The gas-liquid phase change material based on synthetic mineral oil according to claim 1, characterized in that, The stabilizer is a compound of metal passivating agent and anti-settling agent.

7. The gas-liquid phase change material based on synthetic mineral oil according to claim 6, characterized in that, The metal passivating agent is a benzotriazole derivative, and the anti-settling agent is fumed silica, with a weight ratio of 1:1 to 3:

1.

8. The method for preparing gas-liquid phase change materials based on synthetic mineral oil according to any one of claims 1-7, characterized in that, Includes the following steps: S1: Weigh out the synthetic mineral oil, modifier, phase change modifier, antioxidant, and stabilizer according to the specified weight parts, and set aside. S2: Add synthetic mineral oil to the reactor, heat to 60-80℃, stir at 200-400r / min for 10-20min to make the oil phase uniform; S3: Add the modifier and phase change regulator to the reactor in sequence, heat to 90-110℃, keep warm and stir for 30-60 minutes to achieve full grafting and mixing of components; S4: Cool to 50-60℃, add antioxidants and stabilizers, and continue stirring for 20-40 minutes; S5: After stirring, filter the mixture with a filtration accuracy of 0.1-0.5μm to remove impurities and obtain a gas-liquid phase change material based on synthetic mineral oil.

9. The method for preparing gas-liquid phase change materials based on synthetic mineral oil according to claim 8, characterized in that, During the heat preservation and stirring process in step S3, nitrogen gas is introduced for protection, with a nitrogen flow rate of 0.5-1.5 L / min.

10. The application of the gas-liquid phase change material based on synthetic mineral oil according to any one of claims 1-7 in energy storage systems, temperature control devices, or cold chain transportation.

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