High-strength high-toughness low-smoke halogen-free flame-retardant rat-proof cable sheath material and preparation method thereof

Abstract

The invention provides a high-strength high-toughness low-smoke halogen-free flame-retardant rat-proof cable sheath material and a preparation method thereof, and the cable sheath material comprises the following raw materials: 80.0-100.0 parts of a polymer matrix, 80.0-100.0 parts of an inorganic flame retardant, a functional biomass rat-proof agent, 2.0-4.0 parts of a vulcanizing agent and 0.5-1.0 part of a vulcanization accelerator, wherein the functional biomass rat-proof agent is prepared from bio-based dihydric alcohol, bio-based diisocyanate and capsaicin through a one-pot method, and the cable sheath material is obtained by adding the raw materials into an extruder in proportion for melting, blending and extruding and then carrying out cooling curing, traction, grain-sized dicing and drying. The obtained cable sheath material has high strength, high toughness, high flame retardance and long-acting rat-proof performance, and meets the requirements of high mechanical property, flame retardance and long-acting rat-proof performance of materials in the field of cables.

Description

Technical Field

[0001] The invention belongs to the field of polymer material technology and science, and specifically relates to a high-strength, high-toughness, low-smoke, halogen-free, flame-retardant and rat-proof cable sheath material and a preparation method thereof. Background Art

[0002] The cable sheath is the outermost layer of the cable. As the most important barrier to protect the internal structure of the cable, it is not only related to the safety of cable laying and use, but also to the actual service life of the cable. With the growing demand for electricity in modern society, the safety, reliability and durability of cables as an important carrier of power transmission have become particularly important.

[0003] However, during use, cables are not only affected by environmental factors such as oxygen, heat, light, force, and chemical erosion, but also by termites, rats and other organisms, which not only cause power outages and signal failures, but may also cause safety accidents such as fires. In addition, cables often produce a large amount of smoke and harmful gases during the combustion process, which not only causes environmental pollution, but also causes great harm to human health. This requires that the cable sheath material must have the characteristics of high strength and toughness, low smoke and halogen-free flame retardant, and rodent-proof while meeting the basic preparation performance requirements. Traditional cable sheath materials are difficult to meet the diversified needs of the market.

[0004] To solve the above problems, researchers have introduced inorganic flame retardants to improve the halogen-free flame retardant properties of materials, but their flame retardant efficiency is low, and a high filling amount is often required to achieve the ideal flame retardant effect. At the same time, the high surface energy and strong hydrophilicity lead to poor compatibility with the non-polar polymer matrix commonly used in cable materials, resulting in a decrease in the mechanical properties of the composite material. In order to prevent biological erosion, researchers have used the addition of rodent-proof agents or physical methods to form armored structures to improve their rodent-proof properties, but these methods are prone to high costs, unstable service, and environmental unfriendliness. At present, natural plant extracts such as capsaicin are mostly used to achieve good rodent-proof effects by stimulating the smell, taste and nerves of mice. However, capsaicin has poor thermal stability and is prone to small molecule migration. It is easy to sublimate and migrate to the surface of the material during the processing and laying of wires and cables, which greatly reduces the service life and service stability of cable materials and cannot meet the application requirements of materials in complex environments.

[0005] Therefore, the development of a new type of cable sheath material that can achieve high strength, high toughness, low smoke, halogen-free, flame retardant and rodent-proof properties is of great significance to the development of the cable industry. Summary of the invention

[0006] Based on the above problems existing in the prior art, the purpose of the present invention is to provide a cable sheath material and a preparation method thereof, which can give the material the characteristics of high strength, high toughness, low smoke and halogen-free flame retardancy and rodent resistance through the synergistic effect of functional biomass rodent repellent and other materials.

[0007] In order to achieve the purpose, the present invention adopts the following technical scheme:

[0008] A high-strength, high-toughness, low-smoke, halogen-free, flame-retardant, and rat-proof cable sheath material, characterized in that the raw materials include, by mass:

[0009]

[0010]

[0011] The functional biomass rodent repellent is a polyurethane prepolymer containing a capsaicin end-capping structure, and its general structural formula is:

[0012]

[0013] Among them, R1 is a structural unit in bio-based diisocyanate, and R2 is a structural unit in bio-based diol.

[0014] In some embodiments of the present invention, the method for preparing the functional biomass rodent repellent comprises the following steps:

[0015] (1) Adding bio-based diol into a reactor, and stirring under vacuum at 100 to 105° C. for 0.5 to 1.0 h to remove water contained in the bio-based diol.

[0016] (2) Cool the bio-based diol removed from the water in step (1) to 75-80°C, add the bio-based diisocyanate and the catalyst, heat to 85-95°C, and react with mechanical stirring for 3-4 hours; then add capsaicin and the solvent, and continue to react at 85-95°C for 3-5 hours. After the reaction is completed, degassing is performed at room temperature in a vacuum to obtain a functional biomass rodent repellent. The molar ratio of the bio-based diol, the bio-based diisocyanate and the capsaicin is 1:2-3:2-4.

[0017] In some embodiments of the present invention, the polymer matrix is ​​a blend of one or more of polyethylene, polypropylene, ethylene-vinyl acetate copolymer and polyvinyl chloride, wherein the polymer matrix has a tensile strength of 5 to 30 MPa and an elongation at break of 150 to 800%.

[0018] In some embodiments of the present invention, the inorganic flame retardant is a compound of one or more of magnesium hydroxide, aluminum hydroxide and ammonium polyphosphate.

[0019] In some embodiments of the present invention, the vulcanizing agent is a compound of one or more of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, benzoyl peroxide, di-tert-butyl peroxide and dicumyl peroxide.

[0020] In some embodiments of the present invention, the vulcanization accelerator is a compound of one or more of metal oxide, triallyl cyanurate and trimethylolpropane triacrylate.

[0021] The present invention also proposes a method for preparing the high-strength, high-toughness, low-smoke, halogen-free, flame-retardant and rat-proof cable sheath material, comprising the following steps:

[0022] The polymer matrix is ​​vacuum dried at 40-60°C for 12-24h; the dried polymer matrix, inorganic flame retardant and functional biomass rodent repellent are added into a high-speed mixer in proportion, mixed at a speed of 500-1200rpm for 15-20min to obtain a mixture, and then extruded and granulated at 100-120°C by a twin-screw extruder to obtain a modified material; the modified material, vulcanizer and vulcanization accelerator are melted, blended and extruded at 160-180°C by a twin-screw extruder, and then cooled, solidified, pulled, pelletized and dried to obtain a high-strength, high-toughness, low-smoke, halogen-free flame-retardant and rodent-proof cable sheath material.

[0023] The present invention has the following beneficial effects:

[0024] The present invention adopts a polyurethane prepolymer containing a capsaicin end-capping structure as a functional biomass rodent repellent, and the capsaicin used for the end-capping imparts rodent-proof properties to the composite material, and the macromolecular rodent repellent can reduce the irritation and migration rate of capsaicin, thereby improving the service stability and service life of the cable sheath material. The functional biomass rodent repellent of the present invention can also form non-covalent interactions such as hydrogen bonds with the surface functional groups of the flame retardant, improve its dispersion state in the polymer matrix, construct a solid filler network, and improve the mechanical properties and flame retardant efficiency of the material. The cable sheath material of the present invention has the characteristics of high strength, high toughness, low smoke halogen-free flame retardancy and rodent resistance, and the material preparation process is simple and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a Fourier infrared spectrum of the functional biomass rodent repellent prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0026] The present invention will be described in more detail below through specific examples, but the protection scope of the present invention is not limited to these examples.

[0027] The raw material composition of the cable sheath material in the following embodiments and comparative examples is shown in Table 1:

[0028] Table 1 Raw materials and dosage of cable sheath materials in various embodiments and comparative examples (proportion by mass)

[0029]

[0030] The inorganic flame retardant in the table is magnesium hydroxide, the vulcanizing agent is diisopropylbenzene peroxide, and the vulcanization accelerator is zinc oxide.

[0031] Example 1

[0032] The functional biomass rodent repellent used in this embodiment is a polyurethane prepolymer containing a capsaicin end-capping structure, and its preparation includes the following steps:

[0033] 0.01 mol of PCDL2000 was placed in a reactor and stirred under vacuum at 100°C for 30 min, then cooled to 80°C, 0.02 mol of IPDI and 0.15 g of catalyst organic bismuth were added, the temperature was raised to 90°C, and the reaction was mechanically stirred for 3 h. 0.02 mol of capsaicin and 10 mL of acetone were added to the reactor, and the reaction was continued at 90°C for 4 h. After the reaction was completed, the capsaicin-terminated polyurethane prepolymer was obtained after vacuum degassing at room temperature. Its structural formula is shown below:

[0034]

[0035] Figure 1 This is a Fourier transform infrared spectrum of the functional biomass rodent repellent prepared in this example. From the characteristic peaks of specific groups in the spectrum, it can be seen that the functional biomass rodent repellent prepared in this example is successfully synthesized.

[0036] The raw materials and formula of the cable sheath material of this embodiment are shown in Table 1, and the preparation method thereof is carried out according to the following steps:

[0037] First, polyethylene (PE, tensile strength of 25MPa, elongation at break of 700%) was vacuum dried at 60°C for 12h. Then PE, inorganic flame retardant and functional biomass rodent repellent were added to a high-speed mixer in proportion, mixed at a speed of 1000rpm for 20min to obtain a mixture, and then extruded and granulated at 100°C by a twin-screw extruder to obtain a modified material. The modified material, vulcanizer and vulcanization accelerator were melted, blended and extruded at 170°C by a twin-screw extruder, and then cooled, solidified, pulled, pelletized and dried to obtain a high-strength, high-toughness, low-smoke, halogen-free flame-retardant cable sheath material.

[0038] Example 2

[0039] The raw materials and formula of the cable sheath material of this embodiment are shown in Table 1. The preparation process is the same as that of Example 1, except that polypropylene (PP, tensile strength of 20 MPa, elongation at break of 600%) is used as the polymer matrix.

[0040] Example 3

[0041] The raw materials and formula of the cable sheath material of this embodiment are shown in Table 1. The preparation process is the same as that of Example 1, except that ethylene-vinyl acetate copolymer (EVA, tensile strength of 22 MPa, elongation at break of 800%) is used as the polymer matrix.

[0042] Comparative Example 1

[0043] The raw materials and formula of the cable sheath material of this comparative example are shown in Table 1. The preparation method is the same as that of Example 1, except that the amount of the functional biomass rodent repellent added is 0.

[0044] Comparative Example 2

[0045] The raw materials and formula of the cable sheath material of this comparative example are shown in Table 1. The preparation method is the same as that of Example 2, except that the amount of the functional biomass rodent repellent added is 0.

[0046] Comparative Example 3

[0047] The raw materials and formula of the cable sheath material of this comparative example are shown in Table 1. The preparation method is the same as that of Example 3, except that the amount of the functional biomass rodent repellent added is 0.

[0048] Comparative Example 4

[0049] The raw materials and formula of the cable sheath material of this comparative example are shown in Table 1. The preparation method is the same as that of Example 3, except that the amount of functional biomass rodent repellent added is 0, and 8 parts of capsaicin are directly added as the rodent repellent.

[0050] Comparative Example 5

[0051] The raw materials and formula of the cable sheath material of this comparative example are shown in Table 1. The preparation method is the same as that of Example 3, except that the amount of functional biomass rodent repellent added is 0, and 8 parts of non-capsaicin-terminated polyurethane prepolymer (the preparation method is the same as the preparation method of the capsaicin-terminated polyurethane prepolymer in Example 1, except that the amount of capsaicin added is 0) are directly added as rodent repellent.

[0052] The cable sheath materials prepared in the above comparative examples and embodiments were hot-pressed to prepare test specimens, wherein the test standard is:

[0053] Tensile strength, tested according to ISO 527-3:1995 standard, rate is 250mm / min;

[0054] Elongation at break, tested according to ISO 527-3:1995 standard, rate is 250mm / min;

[0055] Limiting oxygen index, tested according to ISO 4589-2:2096 standard;

[0056] Rodent-proof performance, tested according to GB / T 34016-2017 standard.

[0057] The main performance indicators of the cable sheath materials prepared in Examples 1-3 and Comparative Examples 1-5 are shown in Tables 2 and 3:

[0058] Table 2 Performance test results of various embodiments and comparative examples

[0059]

[0060] Table 3 Test results of rodent-proof performance of various embodiments and comparative examples

[0061]

[0062] It can be seen from Table 2 and Table 3 that the comprehensive performance of Example 3 is the best.

[0063] Compared with Example 3, although the capsaicin-terminated functional biomass rodent repellent synthesized by one-pot method using PCDL2000, IPDI and capsaicin can also achieve the simultaneous improvement of its mechanical properties, flame retardant properties and rodent repellent properties, its compatibility with PE and PP matrices is lower than that of EVA.

[0064] Compared with Example 1, Example 2 compared with Example 2, and Example 3 compared with Example 3, no functional biomass rodent repellent was introduced, and the highly filled inorganic particles were easily agglomerated in the matrix and difficult to be evenly distributed, resulting in poor mechanical properties, low flame retardant efficiency, and no rodent repellent performance. The introduction of the functional biomass rodent repellent can form non-covalent interactions such as hydrogen bonds with the surface functional groups of the inorganic flame retardant, improve its dispersion state in the polymer matrix, construct a solid filler network, and improve the mechanical properties and flame retardant efficiency of the material. At the same time, the introduction of capsaicin can improve the rodent repellent performance of the cable sheath material.

[0065] Comparative Example 4, Comparative Example 5, and Example 3 Compared with Comparative Example 3, although the addition of capsaicin alone can improve the rodent-proof performance of the cable sheath material, the tensile strength and flame retardant properties are reduced; although the addition of a polyurethane prepolymer not terminated with capsaicin alone can improve the mechanical and flame retardant properties of the cable sheath material, it cannot impart rodent-proof performance to the cable sheath material; and the introduction of functional biomass rodent repellent can synergistically improve the mechanical properties, flame retardant properties and rodent-proof performance of the cable sheath material.

[0066] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept, such as the technical solution formed by replacing the above features with the technical features with similar functions disclosed in this application (but not limited to). In addition to the technical features described in the specification, the remaining technical features are known technologies to those skilled in the art. In order to highlight the innovative features of the present invention, the remaining technical features will not be described in detail here.

Claims

1. A high-strength, high-toughness, low-smoke, halogen-free, flame-retardant, rat-proof cable sheath material, characterized in that: The raw materials include by mass: Wherein, the functional biomass rodent repellent is a polyurethane prepolymer containing a capsaicin end-capping structure.

2. The high-strength, high-toughness, low-smoke, halogen-free, flame-retardant and rat-proof cable sheath material according to claim 1, characterized in that: The general structural formula of the functional biomass rodent repellent is: Among them, R1 is a structural unit in bio-based diisocyanate, and R2 is a structural unit in bio-based diol.

3. The high-strength, high-toughness, low-smoke, halogen-free, flame-retardant and rat-proof cable sheath material according to claim 1, characterized in that: The polymer matrix is ​​a blend of one or more of polyethylene, polypropylene, ethylene-vinyl acetate copolymer and polyvinyl chloride, wherein the tensile strength of the polymer matrix is ​​5-30 MPa and the elongation at break is 150-800%.

4. The high-strength, high-toughness, low-smoke, halogen-free, flame-retardant and rat-proof cable sheath material according to claim 1, characterized in that: The inorganic flame retardant is a compound of one or more of magnesium hydroxide, aluminum hydroxide and ammonium polyphosphate.

5. The high-strength, high-toughness, low-smoke, halogen-free, flame-retardant and rat-proof cable sheath material according to claim 1, characterized in that: The vulcanizing agent is a compound of one or more of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, benzoyl peroxide, di-tert-butyl peroxide and dicumyl peroxide.

6. The high-strength, high-toughness, low-smoke, halogen-free, flame-retardant and rat-proof cable sheath material according to claim 1, characterized in that: The vulcanization accelerator is a compound of one or more of metal oxide, triallyl cyanurate and trimethylolpropane triacrylate.

7. The high-strength, high-toughness, low-smoke, halogen-free, flame-retardant and rat-proof cable sheath material according to claim 1, characterized in that: The preparation method of the functional biomass rodent repellent comprises the following steps: (1) adding bio-based diol into a reactor, and stirring under vacuum at 100 to 105° C. for 0.5 to 1.0 h to remove water contained in the bio-based diol; (2) Cooling the bio-based diol removed from the water in step (1) to 75-80° C., adding bio-based diisocyanate and a catalyst, heating to 85-95° C., and mechanically stirring to react for 3-4 hours; then adding capsaicin and a solvent, and continuing to react at 85-95° C. for 3-5 hours; after the reaction is completed, degassing at room temperature under vacuum to obtain the functional biomass rodent repellent.

8. The high-strength, high-toughness, low-smoke, halogen-free, flame-retardant and rat-proof cable sheath material according to claim 7, characterized in that: The molar ratio of the bio-based diol, the bio-based diisocyanate and capsaicin is 1:2-3:2-4.

9. A method for preparing the high-strength, high-toughness, low-smoke, halogen-free, flame-retardant and rodent-proof cable sheath material according to any one of claims 1 to 8, characterized in that: The following steps are involved: The polymer matrix is ​​vacuum dried at 40-60°C for 12-24h; the dried polymer matrix, inorganic flame retardant and functional biomass rodent repellent are added into a high-speed mixer in proportion, mixed at a speed of 500-1200rpm for 15-20min to obtain a mixture, and then extruded and granulated by a twin-screw extruder at 100-120°C to obtain a modified material; the modified material, vulcanizer and vulcanization accelerator are melted, blended and extruded by a twin-screw extruder at 160-180°C, and then cooled, solidified, pulled, pelletized and dried to obtain a high-strength, high-toughness, low-smoke, halogen-free flame-retardant and rodent-proof cable sheath material.

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