MPP cable protection tube with strong Vicat performance and preparation method thereof

Abstract

The present invention discloses an MPP cable protection tube with strong Vicat performance and a preparation method thereof, wherein the material of the MPP cable protection tube with strong Vicat performance comprises modified polypropylene, modified calcium sulfate whisker, antioxidant and filler; the modified polypropylene is prepared by reacting a heat-resistant silane coupling agent with copolymerized polypropylene; the heat-resistant silane coupling agent has a structure as shown in the following formula A. The MPP cable protection tube with strong Vicat performance provided by the present invention is based on the excellent high temperature resistance of the modified polypropylene prepared by reacting the heat-resistant silane coupling agent with copolymerized polypropylene and doping with modified calcium sulfate whisker, which can not only make the prepared MPP cable protection tube have excellent Vicat performance, but also have excellent compatibility and bonding stability between the components, which can further improve the Vicat performance of the MPP cable protection tube, so that it can be widely used in the field of cable protection tubes.

Description

Technical Field

[0001] The invention relates to the technical field of MPP cable protection tubes, and in particular to an MPP cable protection tube with strong Vicat performance and a preparation method thereof. Background Art

[0002] In recent years, with the increasing demand for urban electricity, the density of electricity consumption has become higher and higher. Due to restrictions on power supply safety, construction space, and environmental protection, overhead lines usually use underground cables to build transmission and distribution line networks after entering urban areas. Power cable lines have the advantages of occupying less ground and space, safe and reliable power supply, low possibility of electric shock, significantly improved power factor of the power system, simple and convenient operation and maintenance, outstanding urban beautification effect, and good confidentiality. Therefore, the proportion of urban power networks has increased year by year. Among them, cables, as the main facilities for power transmission, play an irreplaceable role.

[0003] The cable is made of one or more mutually insulated conductors and an outer insulating protective layer. It is a wire that transmits electricity or information from one place to another. The cable protection tube is a protective tube with a certain mechanical strength that is laid on the outer layer of the cable to prevent the cable from being damaged. The cable protection tube is mainly installed in the area where the communication cable and the power line intersect to prevent the power line from being broken and causing a short circuit accident, causing the communication cable and the wire rope to be energized, so as to protect the cable, switch, movement board, and even the whole machine from being burned out. It also plays a certain isolation role in the magnetic field interference of the power line.

[0004] MPP cable protection tube, also known as MPP power tube and MPP power cable protection tube, refers to a metal protection tube with a certain mechanical strength laid on the outer layer of the cable to prevent the cable from being damaged. The cable protection tube is mainly installed in the area where the communication cable and the power line intersect to prevent the power line from breaking and causing a short circuit accident, causing the communication cable and the wire rope to be energized, so as to protect the cable, switch, movement board, and even the whole machine from being burned out.

[0005] Modified polypropylene (MPP) power pipes have the characteristics of high temperature resistance, high heat resistance and external pressure resistance. They are suitable for high-voltage transmission line cable pipes above 10KV and are increasingly widely used in today's power field. However, in actual use, due to the limitations of its own materials and strength, the MPP cable protection pipes in the existing technology have poor adaptability to more extreme environments, insufficient resistance to high temperature environments and deformation, and poor toughness. Its Vicat performance still needs to be improved, resulting in the application scope and service life of the MPP cable protection pipe being limited, affecting the value of the material.

[0006] Therefore, there is an urgent need for an MPP cable protection tube with high temperature resistance, good stability and toughness, and strong Vicat performance. Summary of the invention

[0007] Purpose of the invention: In view of the defects of the prior art, the purpose of the present invention is to provide an MPP cable protection tube with high temperature resistance, good stability and toughness, and strong Vicat performance, and a preparation method thereof.

[0008] Technical solution:

[0009] A MPP cable protection tube with strong Vicat performance, wherein the material of the MPP cable protection tube with strong Vicat performance comprises modified polypropylene, modified calcium sulfate whiskers, antioxidants and other fillers;

[0010] The modified polypropylene is prepared by reacting a heat-resistant silane coupling agent with copolymerized polypropylene;

[0011] The heat-resistant silane coupling agent has a structure shown in the following formula A:

[0012]

[0013] Furthermore, the modified calcium sulfate whisker is prepared by the following steps: adding a surfactant and deionized water into a reactor, stirring evenly and heating to 60-70° C., adding calcium sulfate whisker and keeping the temperature for reaction for 30-50 minutes, cooling, filtering, washing and drying to obtain the modified calcium sulfate whisker.

[0014] The present invention can effectively improve the toughness and strength of the material by doping the modified calcium sulfate whisker into the material, and can also increase the density of the molecular chain network of the polypropylene material, limit the thermal movement of the molecular chain, and thus improve the high temperature resistance of the material.

[0015] Furthermore, the modified calcium sulfate whisker is obtained by modification with a surfactant; the surfactant is selected from one of cocamidopropylamine oxide, laurylamidepropylamine oxide or dodecyldimethylamine oxide; and the mass ratio of the surfactant to the calcium sulfate whisker is 1:15-20.

[0016] The present invention modifies the calcium sulfate whisker by using a surfactant, and the amine surfactant can significantly improve the compatibility and bonding strength between the amine surfactant and the modified polypropylene, thereby maintaining the stability of the overall performance of the material. Meanwhile, the calcium sulfate whisker modified by the surfactant can be uniformly dispersed in the material, so that the material has excellent uniformity, and the performance effect of various properties can be further improved.

[0017] Furthermore, the heat-resistant silane coupling agent is prepared by the following steps: in a reactor, diisopropylethoxysilane and 1,1-diphenylethylene are added in sequence, protective gas is introduced, the temperature is raised to 60-70°C and stirred for 30-40 minutes, a catalyst is added and the reaction is kept warm for 3-4 hours, and then the heat-resistant silane coupling agent is obtained by cooling, filtering, washing and drying.

[0018] The heat-resistant silane coupling agent of the present invention, on the one hand, has a siloxane structure and a multi-branched structure, which can be linked to each other in the polypropylene segment to form a network structure with excellent toughness and strength, and can significantly improve the mechanical properties of the polypropylene material; on the other hand, the multi-benzene ring structure in the heat-resistant silane coupling agent can not only improve the chemical stability of the polypropylene material, but also improve its steric hindrance and the bond energy of the segment, thereby effectively improving its high temperature resistance.

[0019] Furthermore, the mass ratio of diisopropylethoxysilane to 1,1-diphenylethylene is 1:1.5-2; the catalyst is a platinum catalyst; the content of effective platinum in the catalyst is 1.0×10 of the total mass of the reactants. -5 -5.0×l0 -5 .

[0020] Furthermore, the modified polypropylene is prepared by the following steps: adding copolymerized polypropylene, a heat-resistant silane coupling agent, xylene and deionized water into a reactor, stirring and adjusting the pH to 2-3, then heating to 70-80°C, keeping the temperature for reaction for 2-3 hours, cooling, filtering, washing and drying to obtain the modified polypropylene.

[0021] In the present invention, the modified polypropylene is prepared by reacting a heat-resistant silane coupling agent with a copolymerized polypropylene, which can not only improve the compatibility between various materials based on the structure of the silane coupling agent, but also significantly improve the high temperature resistance and mechanical properties of the polypropylene material, so that the material has excellent Vicat properties.

[0022] Furthermore, the mass ratio of the copolymerized polypropylene, the heat-resistant silane coupling agent, xylene and deionized water is (15-20):(3-5):(40-60):(150-200).

[0023] Furthermore, the antioxidant is selected from one of octylbutyldiphenylamine, 2,6-di-tert-butyl-4-methylphenol or octylated diphenylamine; and the filler is selected from one of calcium carbonate or wollastonite.

[0024] Furthermore, based on the total mass fraction being 100%, the mass percentage of each component is:

[0025] Modified polypropylene 70-75%

[0026] Modified calcium sulfate whisker 5-8%

[0027] Antioxidants 2-3%

[0028] The balance is filler.

[0029] The method for preparing any of the above-mentioned MPP cable protection tubes with strong Vicat performance comprises the following steps:

[0030] (1) adding modified polypropylene, modified calcium sulfate whisker, antioxidant and filler into a high-speed mixer according to proportion, heating to 60-70° C., and mixing at a speed of 1500-2000 r / min for 10-15 minutes to prepare a mixture;

[0031] (2) Extruding the mixed material through a twin-screw extruder to obtain the MPP cable protection tube with strong Vicat performance.

[0032] Beneficial effects:

[0033] (1) The MPP cable protection tube with strong Vicat performance provided by the present invention is prepared by compounding modified polypropylene, modified calcium sulfate whiskers, antioxidants and fillers. The modified polypropylene prepared by reacting a heat-resistant silane coupling agent with copolymerized polypropylene has excellent high temperature resistance and is doped with modified calcium sulfate whiskers. Not only can the prepared MPP cable protection tube have excellent Vicat performance, but also the components have excellent compatibility and bonding stability, which can further improve the Vicat performance of the MPP cable protection tube and enable it to be widely used in the field of cable protection tubes.

[0034] (2) In the MPP cable protection tube with strong Vicat performance provided by the present invention, the modified polypropylene is prepared by reacting copolymerized polypropylene with a heat-resistant silane coupling agent, which can not only improve the compatibility between the materials based on the structure of the silane coupling agent, but also significantly improve the high temperature resistance and mechanical properties of the polypropylene material, so that the material has excellent Vicat performance.

[0035] (3) In the MPP cable protection tube with strong Vicat performance provided by the present invention, on the one hand, the siloxane structure and multi-branched structure in the heat-resistant silane coupling agent can be linked to each other in the polypropylene segment to form a network structure with excellent toughness and strength, which can significantly improve the mechanical properties of the polypropylene material; on the other hand, the multi-benzene ring structure in the heat-resistant silane coupling agent can not only improve the chemical stability of the polypropylene material, but also improve its steric hindrance and the bond energy of the segment, thereby effectively improving its high temperature resistance.

[0036] (4) In the MPP cable protection tube with strong Vicat performance provided by the present invention, by doping modified calcium sulfate whiskers in the material, not only the toughness and strength of the material can be effectively improved, but also the density of the molecular chain network of the polypropylene material can be increased, the thermal movement of the molecular chain can be restricted, and the high temperature resistance of the material can be improved.

[0037] (5) The MPP cable protection tube with strong Vicat performance provided by the present invention is modified by using a surfactant to modify the calcium sulfate whiskers. The amine surfactant can significantly improve its compatibility and bonding strength with the modified polypropylene, thereby maintaining the stability of the overall performance of the material. At the same time, the calcium sulfate whiskers modified by the surfactant can be evenly dispersed in the material, so that the material has excellent uniformity, which can further improve the performance of various properties. DETAILED DESCRIPTION

[0038] The present invention will be described below in conjunction with specific embodiments. It should be noted that the following embodiments are examples of the present invention and are only used to illustrate the present invention, but not to limit the present invention. Other combinations and various modifications within the concept of the present invention may be performed without departing from the spirit or scope of the present invention.

[0039] The platinum catalyst was 965005 purchased from Bailingwei Technology Co., Ltd. and diluted to a mass fraction of 4.0×10 -3 The commercially available MPP cable protection tube is a 160MPP power tube purchased from Anhui Huayu Pipeline Manufacturing Co., Ltd.; the commercially available MPP is MPP2A25HC purchased from Shenzhen Jinchen Plastic Technology Co., Ltd.; the remaining reagents and equipment are conventional reagents and equipment in this technical field.

[0040] Preparation of modified calcium sulfate whiskers

[0041] The modified calcium sulfate whiskers were prepared by the following steps:

[0042] In a reactor, 1 g of cocoyl propylamine oxide and 50 mL of deionized water were added, the mixture was stirred evenly and then heated to 70° C., 15 g of calcium sulfate whiskers were added and the mixture was kept warm for 30 minutes, and then cooled, filtered, washed and dried to obtain the modified calcium sulfate whiskers.

[0043] Preparation of heat-resistant silane coupling agent

[0044] The heat-resistant silane coupling agent is prepared by the following steps:

[0045] In the reactor, 2 g of diisopropylethoxysilane and 3 g of 1,1-diphenylethylene were added in sequence, protective gas was introduced, the temperature was raised to 70° C. and stirred for 40 minutes, 0.08 g of platinum catalyst was added and the temperature was kept for reaction for 4 hours, and then the temperature was cooled, filtered, washed and dried to obtain the heat-resistant silane coupling agent;

[0046] Mass spectrum data of the heat-resistant silane coupling agent: The product was analyzed by LC-MS, and the m / z of the product was 326.21 (100.0%), 327.22 (28.3%), 328.21 (7.1%), and 329.21 (1.1%).

[0047] Preparation of modified polypropylene-1

[0048] The modified polypropylene-1 was prepared by the following steps:

[0049] In the reactor, 2 g of copolymerized polypropylene, 0.5 g of heat-resistant silane coupling agent, 5 g of xylene and 20 mL of deionized water were added, stirred, acetic acid was added to adjust the pH to 2, and then the temperature was raised to 70° C., and the reaction was kept warm for 3 hours, and the modified polypropylene-1 was obtained by cooling, filtering, washing and drying.

[0050] Preparation of modified polypropylene-2

[0051] The preparation method is basically the same as modified polypropylene-1, except that the heat-resistant silane coupling agent is replaced by an equal amount of γ-aminopropyltriethoxysilane.

[0052] Example 1

[0053] The MPP cable protection tube with strong Vicat performance is prepared by the following steps:

[0054] (1) adding modified polypropylene-1, modified calcium sulfate whisker, octylbutyl diphenylamine and calcium carbonate into a high-speed mixer according to proportion, heating to 70° C., and mixing at a speed of 2000 r / min for 15 minutes to obtain a mixture;

[0055] (2) Extruding the mixture through a twin-screw extruder to obtain the MPP cable protection tube with strong Vicat performance;

[0056] The process parameters of the twin-screw extruder are: zone 1 temperature 190°C, zone 2 temperature 180°C, zone 3 temperature 170°C, zone 4 temperature 160°C, die temperature 190°C, screw temperature 130°C, screw speed 12r / min, and traction speed 0.8m / min;

[0057] Taking the total mass fraction as 100%, the mass percentage of each component is:

[0058] Modified Polypropylene-1 70%

[0059] Modified calcium sulfate whisker 8%

[0060] Octylbutyl diphenylamine 2%

[0061] The balance is calcium carbonate.

[0062] Example 2

[0063] Basically the same as Example 1, except that, based on the total mass fraction being 100%, the components and their mass percentages are:

[0064] Modified Polypropylene-1 75%

[0065] Modified calcium sulfate whisker 5%

[0066] Octylated diphenylamine 3%

[0067] The balance is wollastonite.

[0068] Example 3

[0069] Basically the same as Example 1, except that, based on the total mass fraction being 100%, the components and their mass percentages are:

[0070] Modified Polypropylene-1 72%

[0071] Modified calcium sulfate whisker 7%

[0072] 2,6-di-tert-butyl-4-methylphenol 3%

[0073] The balance is wollastonite.

[0074] Comparative Example 1

[0075] Commercially available MPP cable protection tube.

[0076] Comparative Example 2

[0077] The method is basically the same as Example 1, except that the modified calcium sulfate whiskers are replaced by an equal amount of calcium carbonate.

[0078] Comparative Example 3

[0079] The method is basically the same as Example 1, except that the modified calcium sulfate whiskers are replaced by an equal amount of calcium sulfate whiskers.

[0080] Comparative Example 4

[0081] The process is basically the same as Example 1, except that the modified polypropylene-1 is replaced by an equal amount of commercially available MPP.

[0082] Comparative Example 5

[0083] The method is basically the same as Example 1, except that modified polypropylene-1 is replaced by modified polypropylene-2.

[0084] Performance Testing

[0085] According to the testing standard of DL / T 802.7-2010 Technical Conditions for Conduits for Power Cables, the tensile strength, elongation at break, flexural strength and Vicat softening temperature of the products of Examples 1-3 and Comparative Examples 1-5 were tested.

[0086] The test results are shown in the following table:

[0087] Tensile strength(MPa) Elongation at break (%) Bending strength(MPa) Vicat softening temperature(℃) Example 1 30.8 590 43.6 172 Example 2 30.6 595 43.7 173 Example 3 30.8 590 43.7 172 Comparative Example 1 25.8 510 33.8 141 Comparative Example 2 26.4 525 35.6 166 Comparative Example 3 27.9 535 35.9 167 Comparative Example 4 28.7 575 40.8 158 Comparative Example 5 29.4 580 41.2 160

[0088] According to the comparison of the test results of Examples 1-3 with those of Comparative Example 1, the MPP cable protection tube with strong Vicat performance provided by the present invention has better toughness, mechanical strength and Vicat performance than the MPP cable protection tube in the prior art, and can be widely used in the field of cable protection tubes.

[0089] According to the comparison of the test results of Examples 1-3 and Comparative Examples 2-3, it can be seen that the MPP cable protection tube with strong Vicat performance provided by the present invention can effectively improve the toughness and strength of the material by doping surfactant-modified calcium sulfate whiskers into the material, and can improve the high temperature resistance of the material.

[0090] According to the comparison of the test results of Examples 1-3 and Comparative Examples 4-5, it can be seen that the MPP cable protection tube with strong Vicat performance provided by the present invention is modified by a heat-resistant silane coupling agent on copolymerized polypropylene, which can significantly improve the high temperature resistance of the material and further improve the toughness and strength of the material.

[0091] The above implementation modes are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it, 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. An MPP cable protection tube with strong Vicat performance, characterized in that: The material of the MPP cable protection tube with strong Vicat performance comprises modified polypropylene, modified calcium sulfate whiskers, antioxidants and other fillers; The modified polypropylene is prepared by reacting a heat-resistant silane coupling agent with copolymerized polypropylene; The heat-resistant silane coupling agent has a structure shown in the following formula A:

2. The MPP cable protection tube with strong Vicat performance according to claim 1 is characterized in that: The modified calcium sulfate whisker is prepared by the following steps: adding a surfactant and deionized water into a reactor, stirring evenly and heating to 60-70° C., adding calcium sulfate whisker and keeping the temperature for reaction for 30-50 minutes, cooling, filtering, washing and drying to obtain the modified calcium sulfate whisker.

3. The MPP cable protection tube with strong Vicat performance according to claim 2 is characterized in that: The surfactant is selected from one of cocamidopropylamine oxide, laurylamidepropylamine oxide or dodecyldimethylamine oxide; the mass ratio of the surfactant to the calcium sulfate whisker is 1:15-20.

4. The MPP cable protection tube with strong Vicat performance according to claim 1, characterized in that: The heat-resistant silane coupling agent is prepared by the following steps: in a reactor, diisopropylethoxysilane and 1,1-diphenylethylene are added in sequence, protective gas is introduced, the temperature is raised to 60-70° C. and stirred for 30-40 minutes, a catalyst is added and the temperature is kept for reaction for 3-4 hours, and then the heat-resistant silane coupling agent is obtained by cooling, filtering, washing and drying.

5. The MPP cable protection tube with strong Vicat performance according to claim 4 is characterized in that: The mass ratio of diisopropylethoxysilane to 1,1-diphenylethylene is 1:1.5-2; the catalyst is a platinum catalyst; the effective platinum content in the catalyst is 1.0×10 of the total mass of the reactants. -5 -5.0×l0 -5 .

6. The MPP cable protection tube with strong Vicat performance according to claim 1, characterized in that: The modified polypropylene is prepared by the following steps: adding copolymerized polypropylene, a heat-resistant silane coupling agent, xylene and deionized water into a reactor, stirring and adjusting the pH to 2-3, then heating to 70-80° C., keeping the temperature for reaction for 2-3 hours, cooling, filtering, washing and drying to obtain the modified polypropylene.

7. The MPP cable protection tube with strong Vicat performance according to claim 6, characterized in that: The mass ratio of the copolymerized polypropylene, the heat-resistant silane coupling agent, xylene and deionized water is (15-20): (3-5): (40-60): (150-200).

8. The MPP cable protection tube with strong Vicat performance according to claim 1, characterized in that: The antioxidant is selected from one of octylbutyl diphenylamine, 2,6-di-tert-butyl-4-methylphenol or octylated diphenylamine; and the other filler is selected from one of calcium carbonate or wollastonite.

9. The MPP cable protection tube with strong Vicat performance according to claim 1, characterized in that: Taking the total mass fraction as 100%, the mass percentage of each component is: Modified polypropylene 70-75% Modified calcium sulfate whisker 5-8% Antioxidants 2-3% The balance is other fillers.

10. The method for preparing the MPP cable protection tube with strong Vicat performance according to any one of claims 1 to 9, characterized in that: The following steps are involved: (1) adding modified polypropylene, modified calcium sulfate whiskers, antioxidants and other fillers into a high-speed mixer according to proportion, heating to 60-70° C., and mixing at a speed of 1500-2000 r / min for 10-15 minutes to obtain a mixture; (2) Extruding the mixed material through a twin-screw extruder to obtain the MPP cable protection tube with strong Vicat performance.

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