A polyamide material, its preparation method and application

Abstract

The present invention discloses a polyamide material. The polyamide material comprises the following components by weight: 29-95 parts of polyamide resin, 7.5-30 parts of modified phase change material, 0-40 parts of glass fiber, 0.1-1 part of compatibilizer, and 0-2 parts of auxiliary agent; the modified phase change material is polyethylene glycol modified by silane coupling agent; the compatibilizer is silane coupling agent. The present invention uses silane coupling agent to modify polyethylene glycol, greatly improving the high-temperature stability of polyethylene glycol. The modified polyethylene glycol, combined with a specific compatibilizer and other components in the system, can not only greatly improve the phase change latent heat of the polyamide material, but also the extractable content in the polyamide material is relatively low.

Description

Technical Field

[0001] The present invention belongs to the technical field of polyamide, and more specifically, relates to a polyamide material and a preparation method and application thereof. Background Art

[0002] Polyamide is commonly known as nylon (Nylon), and its English name is Polyamide (PA). It is a general term for polymers containing amide groups in the repeating units of the main chain of macromolecules. Polyamide can be prepared by ring-opening polymerization of lactam, or by condensation polymerization of diamine and dibasic acid. Polyamide plastic is developed on the basis of polyamide fiber. It is the earliest thermoplastic plastic that can bear loads. It is also the variety with the largest output, the most varieties and the widest application among the five major general engineering plastics. Its main varieties include nylon 6, nylon 66, nylon 11, nylon 12, nylon 610, nylon 612, nylon 46, nylon 1010, etc. Among them, nylon 6 and nylon 66 have the highest output, accounting for more than 90% of nylon output. Nylon 11 and nylon 12 have outstanding low-temperature toughness; nylon 46 has excellent heat resistance and has developed rapidly.

[0003] The phase change forms of phase change energy storage materials can generally be divided into four categories: solid-solid phase change, solid-liquid phase change, liquid-gas and solid-gas phase change. Organic phase change materials mainly include paraffin, ester acid, polyethylene glycol and other organic substances. Polyethylene glycol (PEG, H-(O-CH2-CH2) n -OH) is a substance formed by the step-by-step addition polymerization of ethylene oxide and water or ethylene glycol. Depending on the degree of polymerization, it can form a series of polymers with an average molecular weight ranging from 200 to 20,000. It has the characteristics of high phase change enthalpy and low thermal hysteresis effect.

[0004] In the field of electronics and electrical engineering, heat generation has always been an important problem that plagues the use of products. Phase change materials have received widespread attention because they have a large heat storage capacity at lower temperatures. However, phase change materials such as polyethylene glycol themselves have poor heat resistance and are easily decomposed into small molecular substances of polyethylene glycol (also known as extractables, such as monomers or oligomers) during conventional modification processing, thereby losing their heat storage capacity, limiting their scope of use. "Experimental Study on Modification of Low-temperature Phase Change Material Polyethylene Glycol, He Lin, Guangdong University of Technology" discloses the doping of polyethylene glycol with different proportions of expanded graphite and boron nitride. The test results show that expanded graphite and boron nitride can play a certain role in thermal conductivity and shaping, but their effects are still limited. Therefore, how to improve the heat resistance of polyethylene glycol and ultimately improve the heat storage capacity of polyamide materials has become an important problem that needs to be solved urgently. Summary of the invention

[0005] In view of the above-mentioned existing technical problems, the primary purpose of the present invention is to provide a polyamide material, which effectively improves the heat resistance of polyethylene glycol by modifying the polyethylene glycol, thereby increasing the high-temperature phase change latent heat of the polyamide material, and the extractable content is low.

[0006] The second object of the present invention is to provide a method for preparing a polyamide material.

[0007] The third object of the present invention is to provide an application of a polyamide material in the field of electronic and electrical heat storage.

[0008] In order to achieve the above object, the present invention is implemented by the following technical solutions:

[0009] A polyamide material comprises the following components by weight: 29-95 parts of polyamide resin, 7.5-30 parts of modified phase change material, 0-40 parts of glass fiber, 0.1-1 parts of compatibilizer, and 0-2 parts of auxiliary agent; the modified phase change material is polyethylene glycol modified by a silane coupling agent; and the compatibilizer is a silane coupling agent.

[0010] The present invention provides a polyamide material, wherein polyethylene glycol is optimized and modified by a silane coupling agent, and the polyethylene glycol modified by the silane coupling agent can greatly improve the high-temperature stability, while other coupling agents are difficult to achieve the above-mentioned modification effect. Furthermore, the inventors have found that, compared with other coupling agents, when a silane coupling agent is introduced into a polyamide resin system as a compatibilizer, the high-temperature stability and high-temperature phase change latent heat of the polyamide resin system can be further improved. The present invention uses a modified phase change material in a polyamide system in combination with a specific compatibilizer and other components in the system, which can not only greatly improve the phase change latent heat of the polyamide material, but also the content of extractables in the polyamide material is low.

[0011] Specifically, in the present application, the mass percentage of the polyamide resin in the polyamide material is not less than 28%.

[0012] Preferably, the modified phase change material is prepared by mixing polyethylene glycol and a silane coupling agent, heating and stirring, to obtain the modified phase change material.

[0013] In some more specific embodiments, the modified phase change material is prepared by mixing polyethylene glycol and a silane coupling agent in a molten state, and heating and stirring the mixture under a nitrogen atmosphere to obtain the modified phase change material.

[0014] Preferably, the heating temperature is 70-120° C.; and the stirring time is 30-60 min.

[0015] Preferably, the mass ratio of the silane coupling agent to polyethylene glycol is 0.5 to 5:1. Further preferably, the mass ratio of the silane coupling agent to polyethylene glycol is 2 to 4:1. Most preferably, the mass ratio of the silane coupling agent to polyethylene glycol is 3:1. Within this preferred range, the polyamide material has more excellent high-temperature phase change latent heat and lower extractable content.

[0016] Preferably, in the modified phase change material, the silane coupling agent is selected from one or both of (3-aminopropyl)triethoxysilane and (3-glycidoxypropyl)trimethoxysilane.

[0017] Preferably, the compatibilizer is selected from one or both of (3-aminopropyl)triethoxysilane and (3-glycidoxypropyl)trimethoxysilane.

[0018] Preferably, the polyamide resin is selected from one or more of PA6, PA11, PA12, PA46, PA56, PA66, PA610, PA612, PA6T, PA9T, PA10T, PA1010, PA1012.

[0019] Preferably, by weight, the polyamide material comprises the following components: 35 to 60 parts of polyamide resin, 20 to 28 parts of modified phase change material, 20 to 35 parts of glass fiber, 0.15 to 0.2 part of compatibilizer, and 0.5 to 1.5 parts of auxiliary agent.

[0020] Preferably, the number-average molecular weight of the polyethylene glycol is 1000 to 20000. Specifically, the test method for the number-average molecular weight of the polyethylene glycol is: high-temperature GPC method.

[0021] Preferably, the auxiliary agent includes one or both of a lubricant and an antioxidant.

[0022] Preferably, the antioxidant is selected from one or more of hindered phenol antioxidants, hindered amine antioxidants, and phosphite antioxidants.

[0023] Preferably, the lubricant is selected from one or more of fatty acids, fatty acid salts, fatty acid amides, hyperbranched polyesters, fatty acid esters, or acrylic copolymers. Further preferably, the lubricant includes, but is not limited to, one or more of stearic acid, stearate salts, modified ethylene bis-fatty acid amides, hyperbranched polyesters, aliphatic fatty acid esters, or ethylene-acrylic acid copolymers.

[0024] Furthermore, the present invention claims protection for a preparation method of a polyamide material, comprising the following steps:

[0025] (1) Mix polyethylene glycol and a silane coupling agent, heat and stir to obtain the modified phase change material;

[0026] (2) Mix the polyamide resin, modified phase change material, compatibilizer, glass fiber, and auxiliary agent, and perform melt extrusion and pelletizing to obtain the polyamide material.

[0027] Preferably, in the step (1), the polyethylene glycol is molten polyethylene glycol.

[0028] Preferably, in the step (1), heat and stir under a nitrogen atmosphere.

[0029] Preferably, in the step (1), the heating temperature is 70 - 120 °C.

[0030] Preferably, in the step (1), the stirring time is 30 - 60 min.

[0031] Preferably, in the step (2), use a twin-screw extruder for melt extrusion, and the length-diameter ratio of the twin-screw extruder is 32 - 48:1.

[0032] Preferably, in the step (2), the screw speed of the twin-screw extruder is 250 - 500 rpm.

[0033] Preferably, in the step (2), the melt extrusion temperature is 200 - 240 °C.

[0034] Furthermore, the present invention claims the application of a polyamide material in the field of electro-electronic heat storage. Specifically, the polyamide material can be used as a battery bracket, heat storage block, etc., especially in occasions with high heat storage requirements.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] The present invention provides a polyamide material. Using a silane coupling agent to modify polyethylene glycol can greatly improve the high-temperature stability and high-temperature phase change latent heat of polyethylene glycol. The modified polyethylene glycol, combined with a specific compatibilizer and other components in the system, can not only greatly improve the phase change latent heat of the polyamide material, but also the extractable content in the polyamide material is relatively low. Specific Embodiments

[0037] The following further illustrates the present invention in combination with the specification and specific embodiments, but the embodiments do not limit the present invention in any form. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in the technical field.

[0038] The raw materials of the examples and comparative examples are as follows:

[0039] Polyamide 1, PA6, grade HY2500A, manufacturer: Haiyang Chemical Fiber.

[0040] Polyamide 2, PA610, grade A120, manufacturer: Shanghai Yinggu

[0041] Polyethylene glycol 1, number average molecular weight 2000, grade PEG-2000, manufacturer: Jiangsu Dena

[0042] Polyethylene glycol 2, number average molecular weight 8000, grade PEG-8000, manufacturer: Jiangsu Dena

[0043] Polyethylene glycol 3, number average molecular weight 15000, grade PEG-15000, manufacturer: Jiangsu Dena

[0044] Coupling agent 1, silane coupling agent, (3-aminopropyl)triethoxysilane, grade A107147, manufacturer: Shanghai Aladdin

[0045] Coupling agent 2, silane coupling agent, (3-glycidoxypropyl)trimethoxysilane, grade G107576, manufacturer: Aladdin

[0046] Coupling agent 3, isopropyl tri(stearoyl) titanate, grade KR-TTS, manufacturer: Huaian Heyuan Chemical Industry

[0047] Coupling agent 4, 4-[4-(1-hydroxyethyl)-2-methoxy-5-nitrophenoxy]butyric acid, grade H133255, manufacturer: Shanghai Aladdin

[0048] Compatibilizers 1-4 refer to coupling agents 1-4 above

[0049] Glass fiber, ECS10-03-568H, commercially available

[0050] Antioxidant, N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine, commercially available

[0051] Lubricant, ethylene acrylic acid copolymer, commercially available

[0052] Unless otherwise specified, the components (such as antioxidants and lubricants) selected in each parallel example and comparative example are the same commercially available products

[0053] Example 1

[0054] The weight parts of the raw materials used in Example 1 are shown in Table 1

[0055] A preparation method of a polyamide material, the specific steps include:

[0056] (1) Mix molten polyethylene glycol and coupling agent, the mass ratio of polyethylene glycol to coupling agent is 1:3, heat and stir at 70-120 °C for 30-60 min under a nitrogen atmosphere to obtain a modified phase change material

[0057] (2) Mix the polyamide resin, modified phase change material, compatibilizer, glass fiber and additives according to the raw material ratio in Table 1, add them to a twin-screw extruder (with a length-diameter ratio of 40:1 and a screw rotation speed of 350 rpm) for kneading and melting, and extrude and pelletize after homogenization (the extrusion temperature is 200-220 °C) to obtain a polyamide material.

[0058] Examples 2-11

[0059] The weight parts of the raw materials used in the following examples are shown in Table 1.

[0060] The specific preparation steps of the following examples are the same as those of Example 1.

[0061] The difference between Example 4 and Example 1 is that in step (1), the mass ratio of polyethylene glycol to coupling agent is 1:2.

[0062] The difference between Example 5 and Example 1 is that in step (1), the mass ratio of polyethylene glycol to coupling agent is 1:4.

[0063] Comparative Examples 1-7

[0064] The weight parts of the raw materials used in the following comparative examples are shown in Table 2.

[0065] The specific preparation steps of each comparative example are the same as those of Example 1.

[0066] The difference between Comparative Example 4 and Example 1 is that step (1) is not included; in step (2), the polyamide resin, polyethylene glycol, compatibilizer, glass fiber and additives are mixed.

[0067] Table 1

[0068]

[0069]

[0070] Component Example 9 Example 10 Example 11 Polyamide 1 29.3 59.3 94.8 Modified phase change material 1 (Coupling agent 1 + Polyethylene glycol 1) 30 20 7.5 Glass fiber 40 20 0 Compatibilizer 1 0.1 0.2 1 Antioxidant 1 0.2 0.05 Lubricant 1 0.3 0.05

[0071] Table 2 shows the formulation components of each comparative example:

[0072] Table 2

[0073] Component Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Comparative example 5 Comparative example 6 Comparative example 7 Polyamide 1 69.3 69.3 69.3 69.3 69.3 69.3 69.3 Modified phase change material 1 (Coupling agent 1 + Polyethylene glycol 1) 0 0 0 0 10 10 10 Modified phase change material 7 (Coupling agent 3 + Polyethylene glycol 1) 0 10 0 0 0 0 0 Modified phase change material 8 (Coupling agent 4 + Polyethylene glycol 1) 0 0 10 0 0 0 0 Polyethylene glycol 1 10 0 0 2.5 0 0 0 Glass fiber 20 20 20 20 20 0 0 Compatibilizer 1 0.2 0.2 0.2 7.7 0 0 0 Compatibilizer 3 0 0 0 0 0 0.2 0 Compatibilizer 4 0 0 0 0 0 0 0.2 Antioxidant 0.2 0.2 0.2 0.2 0.2 0.2 0.2 Lubricant 0.3 0.3 0.3 0.3 0.3 0.3 0.3

[0074] The raw materials used in the above examples and comparative examples and the prepared polyamide materials are tested according to the following test methods:

[0075] (1) Phase change latent heat: Use a differential scanning calorimeter with a heating rate of 10 °C / min, and calculate the melting enthalpy in the range of 40-70 °C, which is the phase change latent heat.

[0076] (2) Extractable content: Weigh a certain amount of sample, extract it in acetone solution at 40°C for 24 hours, then filter and dry it. Calculate the extractable content according to the following formula: Extractable content = (Initial mass - Mass after drying) / Initial mass × 100%.

[0077] Table 3 shows the performance test results of each example and comparative example respectively.

[0078] Table 3

[0079] Example / Comparative example Latent heat of phase change (J / g) Extractable content (%) Example 1 10.1 1.1 Example 2 9.7 1.2 Example 3 10.3 0.9 Example 4 10.1 1.2 Example 5 9.9 1.5 Example 6 9.8 1.4 Example 7 9.7 1.6 Example 8 10.3 1.2 Example 9 22.9 3.7 Example 10 18.4 2.9 Example 11 9.3 0.8 Comparative example 1 1.0 8.2 Comparative example 2 1.9 9.8 Comparative example 3 2.8 7.7 Comparative example 4 0.5 9.0 Comparative example 5 6.4 9.1 Comparative example 6 6.8 4.0 Comparative example 7 7.5 4.2

[0080] The data of the above examples show that the latent heat of phase change of the polyamide material prepared by the present invention has been significantly improved, and the extractable content has been significantly reduced. The latent heat of phase change of the polyamide material obtained by the above examples is ≥9.3 J / g, and the extractable content is ≤3.7%. Further preferably, the latent heat of phase change of the polyamide material is ≥18.4 J / g.

[0081] It can be seen from Example 1, Example 3, Comparative Example 2 and Comparative Example 3 that when the coupling agent in the modified phase change material is a silane coupling agent, the prepared polyamide material has better latent heat of phase change and lower extractable content. When using a coupling agent other than the silane coupling agent to modify polyethylene glycol, the latent heat of phase change of the prepared polyamide material is significantly reduced, and the extractable content is high, making it difficult to be applied.

[0082] It can be seen from Example 1, Example 8, Comparative Example 6 and Comparative Example 7 that when using different types of silane coupling agents as compatibilizers for polyamide materials, the technical effects of the present invention can be achieved. When using a coupling agent other than the silane coupling agent as a compatibilizer for the polyamide system, the latent heat of phase change of the prepared polyamide material is reduced, and the extractable content increases.

[0083] It can be seen from Example 1 and Comparative Example 1 that when using unmodified polyethylene glycol as the phase change material, since polyethylene glycol is extremely easy to decompose in conventional processing, the latent heat of phase change of the prepared polyamide material is low, and the extractable content is high.

[0084] It can be seen from Example 1 and Comparative Example 4 that directly mixing unmodified polyethylene glycol with a silane coupling agent as a compatibilizer during plastic processing cannot achieve the technical effects of the present invention. It shows that polyethylene glycol needs to be modified with a silane coupling agent first to effectively improve its high-temperature stability.

[0085] The foregoing examples are merely illustrative and are used to explain some of the features of the method of the present invention. The appended claims are intended to claim as broad a scope as can be conceived, and the embodiments presented herein are supported by the applicant's actual test results. Therefore, the applicant's intention is that the appended claims not be limited by the selection of examples that illustrate the features of the present invention. Some of the numerical ranges used in the claims also include sub-ranges within them, and variations within these ranges should also be interpreted as being covered by the appended claims whenever possible.

Claims

1. A polyamide material, characterized in that, By weight parts, it comprises the following components: 29 - 95 parts of polyamide resin, 7.5 - 30 parts of modified phase change material, 0 - 40 parts of glass fiber, 0.1 - 1 part of compatibilizer, and 0 - 2 parts of auxiliary agent; The modified phase change material is polyethylene glycol modified by silane coupling agent; The compatibilizer is silane coupling agent; The preparation method of the modified phase change material is: mixing polyethylene glycol and silane coupling agent, heating and stirring to obtain the modified phase change material; The mass ratio of the silane coupling agent to polyethylene glycol is 0.5 - 5:1; The number average molecular weight of the polyethylene glycol is 1000 - 20000.

2. The polyamide material according to claim 1, characterized in that, The heating temperature is 70 - 120 °C; the stirring time is 30 - 60 min.

3. The polyamide material according to claim 1, characterized in that, In the modified phase change material, the silane coupling agent is selected from one or two of (3 - aminopropyl)triethoxysilane and (3 - glycidoxypropyl)trimethoxysilane.

4. The polyamide material according to claim 1, characterized in that, The compatibilizer is selected from one or two of (3 - aminopropyl)triethoxysilane and (3 - glycidoxypropyl)trimethoxysilane.

5. The polyamide material according to claim 1, wherein The polyamide resin is selected from one or more of PA6, PA11, PA12, PA46, PA56, PA66, PA610, PA612, PA6T, PA9T, PA10T, PA1010, PA1012.

6. The preparation method of the polyamide material according to any one of claims 1 to 5, characterized in that, It comprises the following steps: (1) Mix polyethylene glycol and silane coupling agent, heat and stir to obtain the modified phase change material; (2) Mix polyamide resin, modified phase change material, compatibilizer, glass fiber, and auxiliary agent, melt - extrude and pelletize to obtain the polyamide material.

7. Application of the polyamide material according to any one of claims 1 - 5 in the field of electronic and electrical heat storage.

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