Weather-resistant and corrosion-resistant composition and application thereof in railway cable

Abstract

The invention relates to a weather-resistant and corrosion-resistant composition and application thereof in railway cables. The homo-polypropylene and the ultra-high molecular weight polypropylene are used as matrixes, and the homo-polypropylene and the ultra-high molecular weight polypropylene are mixed to have mechanical properties and weather resistance. On the basis, the self-made fluorine-containing modified polyurethane elastomer is selected, so that the weather resistance can be further improved, and the resin composition is endowed with relatively good corrosion resistance and impact resistance. Wherein the fluorine-containing modified polyurethane elastomer adopts a fluorine-containing diamine monomer and a fluorine-containing end-capping reagent, and the fluorine-containing diamine monomer and the fluorine-containing end-capping reagent are used together, so that the fluorine-containing modified polyurethane elastomer has relatively excellent weather resistance and corrosion resistance.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and more specifically, to a weather-resistant and corrosion-resistant composition and its application in railway cable materials. Background Technology

[0002] Railway cables, acting as the "nerves and blood vessels" supporting the safe and efficient operation of rail transit, are an indispensable part of the railway transportation system, undertaking the functions of safe, reliable, and efficient information transmission and power supply. With the continuous development of modern railway technology, especially the rise of high-speed railways and intelligent railways, the demand for and application of railway cables are becoming increasingly widespread.

[0003] Railway cables include power supply cables, signal cables, data cables, and fiber optic cables. Railway cables are typically used outdoors, where exposure to sunlight and rain places high demands on their weather resistance and corrosion resistance. The materials used in manufacturing railway cables are primarily polypropylene (PP), polyvinyl chloride (PVC), polyethylene (PE), and cross-linked polyethylene (XLPE) to ensure good weather resistance, heat resistance, abrasion resistance, and corrosion resistance.

[0004] CN119490714A discloses a 27.5kV thermoplastic polypropylene cable material for electrified railways and its preparation method. This invention improves toughness and heat resistance by blending modified polypropylene with ethylene propylene rubber and polyethylene, and adding mica powder, antioxidants, glass fiber and rare earth elements to form an ethylene-propylene block copolymer structure. The preparation method uses a twin-screw extrusion process to achieve uniform mixing and granulation, simplifying the process and improving efficiency.

[0005] CN117511086A discloses a corrosion-resistant cable, including a conductor and a corrosion-resistant layer. The corrosion-resistant layer uses PVC material as a matrix and adds modified calcium carbonate. The modified calcium carbonate is obtained by modifying it with a composite coupling agent of stearic acid and N-(6-aminohexyl)aminomethyltriethoxysilane, which changes the surface of the calcium carbonate from hydrophilic to oleophilic, allowing it to be better dispersed in the organic matrix, thereby improving its corrosion resistance.

[0006] Despite extensive research on outdoor railway cables in existing patents and literature, current railway cables still suffer from unsatisfactory weather resistance and corrosion resistance. There is an urgent need for a railway cable that combines both weather resistance and corrosion resistance. Summary of the Invention

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] In a first aspect, the present invention provides a weather-resistant and corrosion-resistant composition comprising the following components in parts by weight:

[0009] 100 parts of homopolymer polypropylene

[0010] 20-30 parts of ultra-high molecular weight polypropylene

[0011] 15-30 parts of fluorinated modified polyurethane elastomer

[0012] 5-15 parts of EPDM rubber

[0013] 3-12 parts compatibilizer

[0014] 10-20 parts of filler

[0015] Antioxidant 1-5 parts

[0016] Lubricant 0.5-3 parts;

[0017] Furthermore, the weight-average molecular weight of the homopolymer polypropylene is 300,000-500,000, and the melt index of the homopolymer polypropylene at 230°C and 2.16 kg load is 2-10 g / 10 min.

[0018] Furthermore, the weight-average molecular weight of the ultra-high molecular weight polypropylene is 1,000,000 to 1,500,000, and the melt index of the ultra-high molecular weight polypropylene at 230°C and a load of 2.16 kg is 0.2 to 0.6 g / 10 min.

[0019] Furthermore, the compatibilizer is one or a combination of two or more of the following: ethylene-acrylate copolymer grafted with maleic anhydride, SEBS grafted with maleic anhydride, and ethylene vinyl acetate grafted with maleic anhydride.

[0020] Furthermore, the filler is one or a combination of two of carbon black and nano-calcium carbonate.

[0021] Furthermore, the antioxidant is one or a combination of two or more of antioxidant 1076, antioxidant 1010, and antioxidant 168.

[0022] Furthermore, the lubricant is one or a combination of two or more of zinc stearate, calcium stearate, and polyethylene wax.

[0023] Furthermore, the preparation process of the fluorinated modified polyurethane elastomer is as follows:

[0024] Polytetrahydrofuran ether glycol is added to a reaction vessel equipped with a stirrer and a thermometer. It is then dehydrated under vacuum at 90-100℃ for 1-2 hours. The temperature is then lowered to 45-60℃, and nitrogen gas is introduced for protection. Diisocyanate, fluorinated diamine monomer, ethylene glycol, and dibutyltin dilaurate are added. The mixture is reacted at 70-90℃ for 2-5 hours. The temperature is then lowered to 55-60℃, and perfluoropentylmethanol, the end-capping agent, is added. The reaction continues for 2-3 hours. After the reaction is completed, the mixture is poured into a preheated mold and placed in an oven at 100-120℃ for 4-6 hours to mature, thus obtaining the product.

[0025] Furthermore, the molar ratio of the polytetrahydrofuran ether diol, diisocyanate, fluorinated diamine monomer, ethylene glycol, and perfluoropentyl methanol is 1:5-6:2:1:2.5-4.5.

[0026] Furthermore, the polytetrahydrofuran ether ether diol is one or a combination of two of polytetrahydrofuran ether ether diol 1000 and polytetrahydrofuran ether ether diol 2000.

[0027] Furthermore, the diisocyanate is one or a combination of two of hexamethylene diisocyanate and isophorone diisocyanate.

[0028] Furthermore, the fluorinated diamine monomer is 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFMB).

[0029] Furthermore, the amount of dibutyltin dilaurate used is 0.5-3 parts.

[0030] Secondly, the present invention provides a preparation process for a weather-resistant and corrosion-resistant composition, the preparation process being as follows:

[0031] The components are mixed evenly in proportion, melt-extruded in a twin-screw extruder, granulated, and dried to obtain a weather-resistant and corrosion-resistant composition.

[0032] Furthermore, the temperatures of the melt extrusion are: 180-190°C in the feeding section, 190-200°C in the mixing section, 200-210°C in the melting section, and 210-220°C in the die head.

[0033] Thirdly, the present invention provides an application of a weather-resistant and corrosion-resistant composition in railway cables.

[0034] This invention uses homopolymer polypropylene and ultra-high molecular weight polypropylene as the matrix, and the combination of the two provides both mechanical properties and weather resistance. Based on this, a self-made fluorinated modified polyurethane elastomer is selected, which further improves weather resistance and imparts good corrosion resistance and impact resistance to the resin composition. The fluorinated modified polyurethane elastomer uses a fluorinated diamine monomer and a fluorinated end-capping agent; the combined use of these two agents gives the fluorinated modified polyurethane elastomer superior weather resistance and corrosion resistance. Detailed Implementation

[0035] The technical solutions of the sub-invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0036] Synthesis example 1

[0037] The preparation process of fluorine-modified polyurethane elastomer is as follows:

[0038] 0.01 mol of polytetrahydrofuran ether diol 1000 was added to a reaction vessel equipped with a stirrer and a thermometer. The mixture was dehydrated under vacuum at 95°C for 1 hour. The temperature was then lowered to 50°C, and nitrogen gas was introduced for protection. 0.05 mol of hexamethylene diisocyanate, 0.02 mol of TFMB, 0.01 mol of ethylene glycol, and 1 g of dibutyltin dilaurate were added. The mixture was reacted at 75°C for 3 hours. The temperature was then lowered to 55°C, and 0.025 mol of perfluoropentyl methanol was added. The reaction was continued for 2 hours. After the reaction was completed, the mixture was poured into a preheated mold and placed in a 100°C oven for 5 hours to mature. This product is denoted as E1.

[0039] Synthesis example 2

[0040] The preparation process of fluorine-modified polyurethane elastomer is as follows:

[0041] 0.01 mol of polytetrahydrofuran ether diol 2000 was added to a reaction vessel equipped with a stirrer and a thermometer. The mixture was dehydrated under vacuum at 95°C for 1 hour. The temperature was then lowered to 50°C, and nitrogen gas was introduced for protection. 0.05 mol of isophorone diisocyanate, 0.02 mol of TFMB, 0.01 mol of ethylene glycol, and 1 g of dibutyltin dilaurate were added. The mixture was reacted at 80°C for 2.5 hours. The temperature was then lowered to 55°C, and 0.025 mol of perfluoropentyl methanol was added. The reaction was continued for 3 hours. After the reaction was completed, the mixture was poured into a preheated mold and placed in an oven at 110°C for 4 hours to mature. This product is denoted as E2.

[0042] Comparative Synthesis Example 1

[0043] The difference from Synthesis Example 1 is that TFMB is replaced with an equimolar amount of polytetrahydrofuran ether diol 1000. The composition of other components, process steps, and parameters are the same as those in Synthesis Example 1, thereby obtaining a fluorinated modified polyurethane elastomer, denoted as C1.

[0044] Comparative Synthesis Example 2

[0045] The difference from Synthesis Example 1 is that perfluoropentylmethanol is replaced with an equimolar amount of pentylmethanol. The composition of other components, process steps, and parameters are the same as those in Synthesis Example 1, thereby obtaining a fluorinated modified polyurethane elastomer, denoted as C2. Example 1

[0046] A weather-resistant and corrosion-resistant composition comprising the following components in parts by weight:

[0047] 100 parts of homopolymer polypropylene

[0048] 25 parts of ultra-high molecular weight polypropylene

[0049] Fluorine-modified polyurethane elastomer E1 18 parts

[0050] 8 parts of ethylene propylene diene monomer (EPDM) rubber

[0051] 6 parts of SEBS grafted with maleic anhydride

[0052] 16 parts of nano calcium carbonate

[0053] Antioxidant 1076 2 parts

[0054] 1.5 parts zinc stearate;

[0055] The homopolymer polypropylene has a weight-average molecular weight of 300,000 and a melt index of 6 g / 10 min at 230°C and a load of 2.16 kg.

[0056] The ultra-high molecular weight polypropylene has a weight-average molecular weight of 1.2 million, and the melt index of the ultra-high molecular weight polypropylene at 230°C and a load of 2.16 kg is 0.4 g / 10 min.

[0057] The preparation process of the weather-resistant and corrosion-resistant composition is as follows: the components are mixed evenly in proportion, melt-extruded in a twin-screw extruder, granulated, and dried to obtain the weather-resistant and corrosion-resistant composition. The melt extrusion temperatures are: 185℃ in the feeding section, 195℃ in the mixing section, 205℃ in the melting section, and 215℃ at the die head. Example 2

[0058] A weather-resistant and corrosion-resistant composition comprising the following components in parts by weight:

[0059] 100 parts of homopolymer polypropylene

[0060] 25 parts of ultra-high molecular weight polypropylene

[0061] Fluorine-modified polyurethane elastomer E2, 18 parts

[0062] 8 parts of ethylene propylene diene monomer (EPDM) rubber

[0063] 6 parts of SEBS grafted with maleic anhydride

[0064] 16 parts of nano calcium carbonate

[0065] Antioxidant 1076 2 parts

[0066] 1.5 parts zinc stearate;

[0067] The homopolymer polypropylene has a weight-average molecular weight of 300,000 and a melt index of 6 g / 10 min at 230°C and a load of 2.16 kg.

[0068] The ultra-high molecular weight polypropylene has a weight-average molecular weight of 1.2 million, and the melt index of the ultra-high molecular weight polypropylene at 230°C and a load of 2.16 kg is 0.4 g / 10 min.

[0069] The preparation process of the weather-resistant and corrosion-resistant composition is as follows: the components are mixed evenly in proportion, melt-extruded in a twin-screw extruder, granulated, and dried to obtain the weather-resistant and corrosion-resistant composition. The melt extrusion temperatures are: 185℃ in the feeding section, 195℃ in the mixing section, 205℃ in the melting section, and 215℃ at the die head. Example 3

[0070] A weather-resistant and corrosion-resistant composition comprising the following components in parts by weight:

[0071] 100 parts of homopolymer polypropylene

[0072] 25 parts of ultra-high molecular weight polypropylene

[0073] Fluorine-modified polyurethane elastomer E2 25 parts

[0074] 10 parts of EPDM rubber

[0075] 6 parts of SEBS grafted with maleic anhydride

[0076] 15 parts of nano calcium carbonate

[0077] Antioxidant 1076 1 part

[0078] 1 part zinc stearate;

[0079] The homopolymer polypropylene has a weight-average molecular weight of 300,000 and a melt index of 6 g / 10 min at 230°C and a load of 2.16 kg.

[0080] The ultra-high molecular weight polypropylene has a weight-average molecular weight of 1.2 million, and the melt index of the ultra-high molecular weight polypropylene at 230°C and a load of 2.16 kg is 0.4 g / 10 min.

[0081] The preparation process of the weather-resistant and corrosion-resistant composition is as follows: the components are mixed evenly in proportion, melt-extruded in a twin-screw extruder, granulated, and dried to obtain the weather-resistant and corrosion-resistant composition. The melt extrusion temperatures are: 185℃ in the feeding section, 195℃ in the mixing section, 205℃ in the melting section, and 215℃ at the die head.

[0082] Comparative Example 1

[0083] Fluorine-modified polyurethane elastomer C1 was used instead of fluorine-modified polyurethane elastomer E1 in Example 1. The composition of other components, process steps, and parameters were the same as in Example 1.

[0084] Comparative Example 2

[0085] Fluorine-modified polyurethane elastomer C2 was used instead of fluorine-modified polyurethane elastomer E1 in Example 1. The composition of other components, process steps, and parameters were the same as in Example 1.

[0086] Comparative Example 3

[0087] The amount of fluorinated modified polyurethane elastomer E1 in Example 1 was adjusted from 18 parts to 35 parts, while the composition of other components, process steps, and parameters were the same as in Example 1.

[0088] Performance testing

[0089] After preparing standard samples from the weather-resistant and corrosion-resistant compositions obtained in each embodiment and comparative example, their performance was tested.

[0090] The test items are as follows:

[0091] 1. Tensile properties: Tested in accordance with ISO 527-2012;

[0092] 2. Oxidation induction time: Tested according to GB / T19466.6-2009;

[0093] 3. Corrosion resistance test:

[0094] (1) Acid treatment: immerse in an aqueous solution of H2SO4 with a pH of 1 at 65°C for 3 hours;

[0095] (2) Alkali treatment: NaOH aqueous solution with pH value of 14 is heated in a 90℃ water bath for 5 hours.

[0096] After preparing standard samples of the same specifications from the weather-resistant and corrosion-resistant compositions obtained in each embodiment and comparative example, the above-described (1) to (2) processes were performed respectively. After drying, the tensile strength was tested, and the tensile strength retention rate was calculated.

[0097] Tensile strength retention rate = tensile strength after test / tensile strength before test × 100%.

[0098] The experimental results are shown in the table below:

[0099] Table 1. Performance test results of the weather-resistant and corrosion-resistant compositions obtained in each embodiment and comparative example.

[0100]

[0101] As shown in Table 1, the weather-resistant and corrosion-resistant composition prepared in this invention not only has high weather resistance but also high acid and alkali resistance. Furthermore, compared to Example 1, Comparative Example 1 used an equimolar amount of polytetrahydrofuran ether ether diol 1000 to replace TFMB (2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl), resulting in a decrease in the tensile strength, weather resistance, acid resistance, and alkali resistance of the weather-resistant and corrosion-resistant composition. Compared to Example 1, Comparative Example 2 used an equimolar amount of pentyl methanol to replace perfluoropentyl methanol, resulting in a decrease in the tensile strength, weather resistance, acid resistance, and alkali resistance of the weather-resistant and corrosion-resistant composition. Compared to Example 1, Comparative Example 3 adjusted the amount of fluorinated modified polyurethane elastomer E1 from 18 parts to 35 parts. Although the weather resistance, acid resistance, and alkali resistance were not significantly affected, the tensile strength of the weather-resistant and corrosion-resistant composition decreased significantly.

[0102] Finally, it should be noted that the above content is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the concept of the invention or exceed the defined scope, they should all fall within the protection scope of the present invention.

Claims

1. A weather-resistant and corrosion-resistant composition, characterized in that, The components include the following parts by weight: 100 parts of homopolymer polypropylene 20-30 parts of ultra-high molecular weight polypropylene 15-30 parts of fluorinated modified polyurethane elastomer 5-15 parts of EPDM rubber 3-12 parts compatibilizer 10-20 parts of filler Antioxidant 1-5 parts Lubricant 0.5-3 parts.

2. The weather-resistant and corrosion-resistant composition according to claim 1, characterized in that, The homopolymer polypropylene has a weight-average molecular weight of 300,000-500,000, and a melt index of 2-10 g / 10 min at 230°C and a load of 2.16 kg.

3. The weather-resistant and corrosion-resistant composition according to claim 1, characterized in that, The ultra-high molecular weight polypropylene has a weight-average molecular weight of 1,000,000 to 1,500,000, and the melt index of the ultra-high molecular weight polypropylene at 230°C and a load of 2.16 kg is 0.2 to 0.6 g / 10 min.

4. The weather-resistant and corrosion-resistant composition according to claim 1, characterized in that, The compatibilizer is one or a combination of two or more of the following: ethylene-acrylate copolymer grafted with maleic anhydride, SEBS grafted with maleic anhydride, and ethylene vinyl acetate grafted with maleic anhydride.

5. The weather-resistant and corrosion-resistant composition according to claim 1, characterized in that, The filler is one or a combination of two of carbon black and nano-calcium carbonate.

6. The weather-resistant and corrosion-resistant composition according to claim 1, characterized in that, The antioxidant is one or a combination of two or more of antioxidants 1076, antioxidant 1010, and antioxidant 168.

7. The weather-resistant and corrosion-resistant composition according to claim 1, characterized in that, The lubricant is one or a combination of two or more of zinc stearate, calcium stearate, and polyethylene wax.

8. The preparation process of a weather-resistant and corrosion-resistant composition according to any one of claims 1-7, characterized in that, The components are mixed evenly in proportion, melt-extruded in a twin-screw extruder, granulated, and dried to obtain a weather-resistant and corrosion-resistant composition.

9. The preparation process of the weather-resistant and corrosion-resistant composition according to claim 8, characterized in that, The temperatures for melt extrusion are: 180-190℃ in the feeding section, 190-200℃ in the mixing section, 200-210℃ in the melting section, and 210-220℃ at the die head.

10. The application of a weather-resistant and corrosion-resistant composition as described in any one of claims 1-7 in railway cables.

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