High-temperature-resistant ethylene-tetrafluoroethylene copolymer composite material as well as preparation method and application thereof

Abstract

The invention discloses a high-temperature-resistant ethylene-tetrafluoroethylene copolymer composite material as well as a preparation method and application thereof. The composite material comprises the following raw materials: 8-10 parts of an ethylene-tetrafluoroethylene copolymer; 0.02 to 0.2 part of an antioxidant; 0.2-1 part of a heat stabilizer; and 0.1 to 0.8 part of a sensitizing agent. The preparation method comprises the following steps: weighing the components according to the mass ratio, internally mixing in an internal mixer for 20-45 minutes, extruding through a screw extruder at the extrusion temperature of 280-340 DEG C after uniformly mixing, and drying to obtain the composite material. During application, the composite material is added into an extruder; extruding at the temperature of 280-340 DEG C to coat the outer surface of the electric wire or the cable; an electric wire or a cable coated with the composite material is subjected to annealing treatment, the annealing temperature is 120-180 DEG C, and the annealing time is 12-24 h. The material has good thermal stability, and the preparation method is simple, low in cost and convenient for large-scale production and application.

Description

Technical Field

[0001] The present invention relates to the technical field of composite materials, and in particular to a composite material of a high temperature resistant ethylene-tetrafluoroethylene copolymer and a preparation method and application thereof. Background Art

[0002] Ethylene-tetrafluoroethylene copolymer (ETFE), as a high-performance material, has emerged in many high-tech fields with its excellent mechanical strength, relatively low density and excellent radiation resistance, especially in the automotive manufacturing, robotics and aerospace industries, as an insulation material for wires and cables, it has received extensive and in-depth attention. Its excellent physical properties and chemical stability make ETFE an ideal choice for insulation materials in these fields, helping to improve the reliability and safety of the overall equipment.

[0003] However, despite the many advantages of ETFE, a significant challenge in its processing cannot be ignored: the difference between the melting point and decomposition temperature of ETFE is relatively small. This feature is particularly prominent in the extrusion process of wire and cable insulation, because the high-temperature processing environment easily triggers the oxidative decomposition reaction of ETFE. This decomposition not only causes the color of the polymer material itself to change, but may also cause defects such as blistering and cracking on the surface of the insulation layer, which seriously weakens the electrical insulation performance and mechanical strength of the product, posing a serious threat to the quality and reliability of the final product.

[0004] In order to solve this problem, researchers have conducted a lot of explorations, and one of the effective strategies is to introduce a third monomer into ETFE. This method effectively reduces the melting point of ETFE by breaking the alternating sequence structure of the original binary copolymer, while enhancing its thermal stability, making the material less likely to decompose during processing, thereby improving processing performance and finished product quality. For example, a number of US patents (such as US4338237, US3308107, US6602107, US3444148 and US3847881) detail the technology of introducing a specific type of modified third monomer into ETFE. These improvements significantly improve the performance of ETFE materials under high-temperature tensile conditions.

[0005] Nevertheless, the current third monomer modification technology, although technologically advanced, has a significant drawback, namely, high cost. The high material cost and complex processing flow not only increase the production cost, but also limit the widespread application of this technology in large-scale industrial production, especially in cost-sensitive application scenarios. This limitation is particularly prominent.

[0006] Therefore, how to explore lower-cost and easier-to-process modification methods while maintaining the excellent performance of ETFE has become a key issue that needs to be urgently addressed in the current field of materials science and engineering technology. Summary of the invention

[0007] The purpose of the present invention is to provide a high temperature resistant ethylene-tetrafluoroethylene copolymer composite material and a preparation method and application thereof.

[0008] In order to achieve the above object, the technical solution adopted by the present invention is:

[0009] A high temperature resistant ethylene-tetrafluoroethylene copolymer composite material, the raw materials of which include the following components in parts by weight:

[0010]

[0011] In a further technical solution, the antioxidant is a mixture of one or more of alkylated diphenylamine, N-phenyl-2-naphthylamine, and dioctyl diphenylamine in any proportion.

[0012] In a further technical solution, the heat stabilizer is a mixture of one or more of cerium oxide, zirconium oxide, tin oxide and silicon dioxide in any proportion.

[0013] In a further technical solution, the sensitizer is a mixture of one or more of the following structural formulas in any proportion:

[0014]

[0015] According to a further technical solution, the ethylene-tetrafluoroethylene copolymer has a melt index of 10 to 35 g / 10 min and a melting point of 240 to 275°C.

[0016] Furthermore, the present invention also discloses a method for preparing a high temperature resistant ethylene-tetrafluoroethylene copolymer composite material, comprising:

[0017] The components are weighed according to the mass ratio, and kneaded in an internal mixer for 20 to 45 minutes. After the kneading is uniform, the components are extruded through a screw extruder at an extrusion temperature of 280 to 340° C. After drying, the high temperature resistant ethylene-tetrafluoroethylene copolymer composite material is obtained.

[0018] Furthermore, the present invention also discloses an application of a high temperature resistant ethylene-tetrafluoroethylene copolymer composite material, comprising:

[0019] (1) adding the prepared high temperature resistant ethylene-tetrafluoroethylene copolymer composite material into an extruder;

[0020] (2) Extrusion at a temperature of 280 to 340°C and coating on the outer surface of the wire or cable;

[0021] (3) Annealing the wire or cable coated with the composite material of the high temperature resistant ethylene-tetrafluoroethylene copolymer, the annealing temperature is 120 to 180° C., and the annealing time is 12 to 24 hours.

[0022] The terms “include,” “including,” “have,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0023] The terms used herein generally have the ordinary meanings of each term used in the art, in the context of the present invention, and in the specific context, unless otherwise noted. Certain terms used to describe the present invention will be discussed below or elsewhere in this specification to provide additional guidance to those skilled in the art regarding the description of the present invention.

[0024] The working principle and advantages of the present invention are as follows:

[0025] 1. The present invention provides a high temperature resistant ethylene-tetrafluoroethylene copolymer composite material, which uses an antioxidant to capture and neutralize free radicals in the system to prevent the composite material from causing molecular chain breakage during oxidation reaction. The decomposition reaction of the composite material in a high temperature environment is delayed by using a thermal stabilizer to absorb heat energy and chemical action. By using a sensitizer to increase the activation energy of the thermal decomposition reaction of the composite material, the thermal decomposition rate of the composite material can be slowed down to a certain extent. In addition, under the synergistic effect of the antioxidant, the thermal stabilizer and the sensitizer, the thermal stability of the composite material of the ethylene-tetrafluoroethylene copolymer can be significantly improved. Based on the above principles, the composite material of the present invention has good thermal stability, and the initial decomposition temperature is as high as 350 to 420°C, which can meet the extrusion processing requirements under high temperature conditions, avoid the degradation of the composite material of the ethylene-tetrafluoroethylene copolymer during the processing, and can be used for cable insulation.

[0026] 2. The preparation method of the high temperature resistant ethylene-tetrafluoroethylene copolymer composite material of the present invention is simple, low in cost, and convenient for large-scale production and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Attached Figure 1 Thermogravimetric curves of Examples 1 to 3 of the present invention and Comparative Example 1;

[0028] Attached Figure 2 This is the appearance diagram of sample 1 after heat aging treatment in Example 1 of the present invention;

[0029] Attached Figure 3 This is the appearance diagram of sample 2 after heat aging treatment in Example 2 of the present invention;

[0030] Attached Figure 4 This is the appearance diagram of sample 3 after heat aging treatment in Example 3 of the present invention;

[0031] Attached Figure 5 This is the appearance diagram of sample 4 after heat aging treatment in comparative example 1 of the present invention. DETAILED DESCRIPTION

[0032] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0033] The present invention will be clearly described below with drawings and detailed descriptions. After understanding the embodiments of the present invention, any person skilled in the art can make changes and modifications based on the techniques taught by the present invention without departing from the spirit and scope of the present invention.

[0034] Embodiment 1:

[0035] A high temperature resistant ethylene-tetrafluoroethylene copolymer composite material is composed of 89wt% ETFE, 1wt% alkylated diphenylamine, 5wt% cerium oxide and 5wt% sensitizer I, wherein the structural formula of sensitizer I is:

[0036] Preparation method of the above-mentioned high temperature resistant ethylene-tetrafluoroethylene copolymer composite material:

[0037] The components were weighed according to their mass ratio, and kneaded in an internal mixer for 30 minutes. After being kneaded evenly, they were extruded through a screw extruder at an extrusion temperature of 300° C. After drying, the high-temperature resistant ethylene-tetrafluoroethylene copolymer composite material was obtained.

[0038] The thermal stability test of the high temperature resistant ethylene-tetrafluoroethylene copolymer composite material of Example 1 was carried out. The test results are shown in Tables 1 and Figure 1 shown.

[0039] Embodiment 2:

[0040] A high temperature resistant ethylene-tetrafluoroethylene copolymer composite material is composed of 90wt% ETFE, 1wt% N-phenyl-2-naphthylamine, 4wt% zirconium oxide and 5wt% sensitizer II, wherein the structural formula of sensitizer II is:

[0041]

[0042] Preparation method of the above-mentioned high temperature resistant ethylene-tetrafluoroethylene copolymer composite material:

[0043] The components were weighed according to their mass ratio, and kneaded in an internal mixer for 35 minutes. After being kneaded evenly, they were extruded through a screw extruder at an extrusion temperature of 300° C. After drying, the high-temperature resistant ethylene-tetrafluoroethylene copolymer composite material was obtained.

[0044] The thermal stability test of the high temperature resistant ethylene-tetrafluoroethylene copolymer composite material of Example 2 was carried out. The test results are shown in Tables 1 and Figure 1 shown.

[0045] Embodiment 3:

[0046] A high temperature resistant ethylene-tetrafluoroethylene copolymer composite material is composed of 92wt% ETFE, 1wt% dioctyldiphenylamine, 3wt% silicon dioxide and 4wt% sensitizer III, wherein the structural formula of sensitizer III is:

[0047]

[0048] Preparation method of the above-mentioned high temperature resistant ethylene-tetrafluoroethylene copolymer composite material:

[0049] The components were weighed according to their mass ratio, and kneaded in an internal mixer for 40 minutes. After being kneaded evenly, they were extruded through a screw extruder at an extrusion temperature of 300° C. After drying, the high-temperature resistant ethylene-tetrafluoroethylene copolymer composite material was obtained.

[0050] The thermal stability test of the high temperature resistant ethylene-tetrafluoroethylene copolymer composite material of Example 3 was carried out. The test results are shown in Tables 1 and Figure 1 shown.

[0051] Comparative Example 1:

[0052] The unmodified ETFE is extruded through a screw extruder at a temperature of 270° C. and dried to obtain the ETFE material.

[0053] The ETFE material of Comparative Example 1 was subjected to a thermal stability test. The test results are shown in Tables 1 and Figure 1 shown.

[0054] Table 1

[0055]

[0056] Combined with the components and preparation methods of Examples 1 to 3 and Comparative Example 1, and through Tables 1 and Figure 1 It can be seen that the composite material of high temperature resistant ethylene-tetrafluoroethylene copolymer has high thermal stability and can meet the requirements of extrusion processing under high temperature conditions. This is mainly attributed to the synergistic effect between the antioxidant, thermal stabilizer and sensitizer used in Examples 1 to 3, which significantly improves the thermal stability of Examples 1 to 3. Comparative Example 1 is not modified and does not involve the use of antioxidants, thermal stabilizers and sensitizers, so the thermal stability is significantly lower than that of each example.

[0057] Thermal aging tests were performed on Examples 1 to 3 and Comparative Example 1 respectively:

[0058] The high temperature resistant ethylene-tetrafluoroethylene copolymer composite material of Example 1 was extruded through a screw extruder at an extrusion temperature of 330°C, annealed at 160°C for 12h, and samples of corresponding sizes were cut according to test requirements. Then, the samples were heat aged at 240°C in a high temperature aging box for 120h to obtain Sample 1.

[0059] The high temperature resistant ethylene-tetrafluoroethylene copolymer composite material of Example 2 was extruded through a screw extruder at an extrusion temperature of 330°C, annealed at 160°C for 12h, and samples of corresponding sizes were cut according to the test requirements. Then, the samples were heat aged at 240°C in a high temperature aging box for 120h to obtain Sample 2.

[0060] The high temperature resistant ethylene-tetrafluoroethylene copolymer composite material of Example 3 was extruded through a screw extruder at an extrusion temperature of 330°C and annealed at 160°C for 12 hours. Samples of corresponding sizes were cut according to test requirements and then subjected to heat aging treatment at 240°C in a high temperature aging box for 120 hours to obtain Sample 3.

[0061] The ETFE material of comparative example 1 was extruded through a screw extruder at an extrusion temperature of 275°C, annealed at 160°C for 12h, and cut into samples of corresponding sizes according to test requirements. Then, the samples were heat aged at 240°C in a high-temperature aging box for 120h to obtain sample 4.

[0062] like Figures 2 to 5 As shown, by observing the materials of sample 4 and samples 1 to 3 after annealing, it can be seen that sample 4 shows discoloration and blistering, and sample 1 only shows discoloration, while samples 2 to 3 corresponding to embodiments 2 to 3 of the present invention do not show discoloration or blistering, indicating that the high temperature resistant ethylene-tetrafluoroethylene copolymer composite material of the present invention has good thermal stability.

[0063] Table 2

[0064] sample Sample 4 Sample 1 Sample 2 Sample 3 color Discoloration, yellowing Discoloration, yellowing No significant changes No significant changes Appearance Foaming No foaming No foaming No foaming

[0065] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A high temperature resistant ethylene-tetrafluoroethylene copolymer composite material, characterized in that: The raw materials include the following components in parts by weight: 8-10 parts of ethylene-tetrafluoroethylene copolymer; Antioxidant 0.02~0.2 parts; Heat stabilizer 0.2~1 part; Sensitizer 0.1~0.8 parts.

2. The high temperature resistant ethylene-tetrafluoroethylene copolymer composite material according to claim 1, characterized in that: The antioxidant is a mixture of one or more of alkylated diphenylamine, N-phenyl-2-naphthylamine and dioctyl diphenylamine.

3. The high temperature resistant ethylene-tetrafluoroethylene copolymer composite material according to claim 1, characterized in that: The thermal stabilizer is a mixture of one or more of cerium oxide, zirconium oxide, tin oxide and silicon dioxide.

4. The high temperature resistant ethylene-tetrafluoroethylene copolymer composite material according to claim 1, characterized in that: The sensitizer is a mixture of one or more of the following structural formulas: 、 、 。 5. The high temperature resistant ethylene-tetrafluoroethylene copolymer composite material according to claim 1, characterized in that: The ethylene-tetrafluoroethylene copolymer has a melt index of 10-35 g / 10 min and a melting point of 240-275° C.

6. A method for preparing a high temperature resistant ethylene-tetrafluoroethylene copolymer composite material, characterized in that: A composite material for preparing the high temperature resistant ethylene-tetrafluoroethylene copolymer according to any one of claims 1 to 5, the preparation method comprising: Weigh each component according to the mass ratio, mix them in an internal mixer for 20-45 minutes, extrude them through a screw extruder after mixing evenly, and extrude them at a temperature of 280-340° C. After drying, the high-temperature resistant ethylene-tetrafluoroethylene copolymer composite material is obtained.

7. An application of a high temperature resistant ethylene-tetrafluoroethylene copolymer composite material, characterized in that: include: (1) adding the high temperature resistant ethylene-tetrafluoroethylene copolymer composite material prepared according to claim 6 into an extruder; (2) Extruded at a temperature of 280-340°C and coated on the outer surface of the wire or cable; (3) Annealing the wire or cable coated with the high temperature resistant ethylene-tetrafluoroethylene copolymer composite material at a temperature of 120 to 180° C. for a time of 12 to 24 hours.

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