An impact-resistant MPP power pipe and its preparation method

Abstract

The present invention discloses an impact-resistant MPP power pipe and its preparation method, belonging to the technical field of power pipe preparation. The preparation method of the impact-resistant MPP power pipe includes the following steps: Step 1: Mix polypropylene, polytrimethylene terephthalate and carbon fiber to obtain a base material; Step 2: Sequentially add a modified flame retardant, a modified toughening agent, a compatibilizer, a coupling agent, a lubricant and an antioxidant to the base material, and fully stir and mix to obtain a mixed material; Step 3: Mix the mixed material using a high-speed mixer, then add it to a twin-screw extruder, extrude, cool and shape, cut and polish to obtain the impact-resistant MPP power pipe. The MPP power pipe prepared by this method has excellent flame retardant performance, mechanical performance, chemical corrosion resistance and impact resistance.

Description

Technical Field

[0001] The present invention belongs to the technical field of power pipe preparation, and particularly relates to an impact-resistant MPP power pipe and a preparation method thereof. Background Art

[0002] Today, with the rapid development of modern cities and industries, the laying and maintenance of power pipelines have become key links in infrastructure construction. Power pipelines not only need to withstand various pressures from the ground, but also have to cope with complex and changing underground environments, such as acid-base soils, humid conditions, and temperature variations. Traditional power pipes, such as PE pipes, are prone to deformation under high temperatures or external forces, seriously affecting the laying and maintenance of cables. Especially in high-temperature environments, the strength of PE pipes will be significantly reduced, posing great potential safety hazards to cable laying in power projects.

[0003] In recent years, MPP power pipes have been widely used in power engineering due to their excellent physical and mechanical properties and electrical insulation properties. MPP power pipes are based on polypropylene as the base material and modified through special formulas, with advantages such as low density, light weight, high strength, corrosion resistance, high temperature resistance, high insulation resistance, and good flame retardancy. These characteristics enable MPP power pipes to provide reliable safety guarantees during power transmission, effectively preventing electrical accidents such as electric leakage and short circuits. At the same time, MPP power pipes also have good flexibility and can be bent according to construction requirements, facilitating laying under different terrain and space conditions and adapting to various complex construction environments.

[0004] Patent CN111019242A discloses an impact-resistant, heat-resistant, and flame-retardant MPP power pipe material, which contains the following components in parts by weight: 50 - 70 parts of polypropylene resin, 15 - 25 parts of heat-resistant filler, 1 - 4 parts of toughening agent, and 10 - 25 parts of flame retardant; the heat-resistant filler is a mixture composed of montmorillonite and talcum powder in a weight ratio of 1:3 - 1:5. The MPP power pipe prepared from the MPP power pipe material of this invention has strong impact resistance, good flame retardancy, high mechanical strength, good heat resistance, excellent comprehensive performance, and stable processing and forming. However, there is still room for improvement in the flame retardancy, mechanical properties, chemical corrosion resistance, and impact resistance of the MPP power pipe material prepared by this method. Summary of the Invention

[0005] The purpose of the present invention is to provide an impact-resistant MPP power pipe and a preparation method thereof, aiming to solve the technical problems of poor flame retardancy, mechanical properties, chemical corrosion resistance, and impact resistance of power pipes in the prior art.

[0006] To achieve the above purpose, the present invention adopts the following technical solutions:

[0007] The present invention provides a preparation method of an impact-resistant MPP power pipe, comprising the following steps:

[0008] Step 1: Mix polypropylene, polytrimethylene terephthalate and carbon fiber to obtain a base material;

[0009] Step 2: Sequentially add a modified flame retardant, a modified toughening agent, a compatibilizer, a coupling agent, a lubricant and an antioxidant to the base material, and fully stir and mix to obtain a mixed material;

[0010] Step 3: Mix the mixed material using a high-speed mixer, then add it to a twin-screw extruder, extrude, cool and shape, cut and polish to obtain an impact-resistant MPP power pipe.

[0011] Preferably, in Step 1, the dosage ratio of polypropylene, polytrimethylene terephthalate and carbon fiber is (60 - 80) g : (10 - 20) g : (10 - 20) g; in Step 2, the dosage ratio of the base material, the modified flame retardant, the modified toughening agent, the compatibilizer, the coupling agent, the lubricant and the antioxidant is (85 - 110) g : (1 - 2) g : (3 - 5) g : (2 - 4) g : (1 - 3) g : (1 - 3) g : (0.5 - 1) g.

[0012] Preferably, the preparation method of the modified flame retardant comprises the following steps:

[0013] Q1: Add erythritol to a mixed solution of N,N-dimethylformamide and petroleum ether, stir and mix to obtain Solution 1, add vanillin to a mixed solution of N,N-dimethylformamide and petroleum ether, stir and mix to obtain Solution 2, then add Solution 1 and Solution 2 to a container, heat and stir, then add citric acid, raise the temperature for reaction, after the reaction ends, cool, add the reacted solution to a sodium bicarbonate solution, precipitate, wash, and vacuum dry to obtain Compound A;

[0014] Q2: Add furfurylamine and natural benzaldehyde to 1,4-dioxane, stir in an ice bath, then add Compound A, continue the reaction in an ice bath, then raise the temperature for reaction, after the reaction ends, under nitrogen protection, continue to raise the temperature for reaction, after the reaction ends, cool, filter, rotary evaporate, dissolve, wash, recrystallize, and vacuum dry to obtain a composite flame retardant.

[0015] In the above process, the synthesis reaction formula of the composite flame retardant is as follows:

[0016]

[0017] The results of mass spectrometry analysis of Compound A are as follows: m / z: 390.13 (100.0%), 391.13 (21.6%), 392.14 (4.0%); the results of mass spectrometry analysis of the composite flame retardant are as follows: m / z: 936.36 (100.0%), 937.37 (63.7%), 938.37 (22.0%), 939.37 (5.4%).

[0018] Preferably, in Q1, the dosage ratio of erythritol, vanillin and citric acid is (4.5 - 5.6) g : (13.13 - 14.25) g : (0.86 - 0.98) g, the heating and stirring temperature is 50 - 55 °C, the stirring time is 30 - 45 min, the temperature for the heating reaction is 110 - 130 °C, the reaction time is 14 - 18 h, and washing is carried out with deionized water and ethanol.

[0019] Preferably, in Q2, the dosage ratio of furfurylamine, natural benzaldehyde, 1,4 - dioxane and Compound A is (4.34 - 5.13) g : (10 - 12) g : (45 - 55) mL : (9.2 - 10.5) g, the ice - bath stirring time is 30 - 45 min, the continued ice - bath reaction time is 1 - 2 h, the temperature for the first heating reaction is 25 - 30 °C, the reaction time is 2 - 3 h, the continued temperature for the heating reaction is 90 - 95 °C, and the reaction time is 10 - 12 h.

[0020] Preferably, the preparation method of the modified toughening agent comprises the following steps:

[0021] S1: Add 3,5 - dihydroxybenzoic acid, castor oil, sulfolane and 4 - dimethylaminopyridine into a reaction vessel, introduce nitrogen, heat and continue the reaction. After the reaction is completed, cool, wash, filter and dry to obtain white solid 1;

[0022] S2: Add white solid 1, epichlorohydrin and isopropyl alcohol into a container, introduce nitrogen, heat and stir magnetically for reaction, then continue to heat up, then add sodium hydroxide and continue to stir magnetically for reaction. After the reaction is completed, carry out suction filtration under reduced pressure, wash, filter and dry under vacuum to obtain the modified toughening agent.

[0023] In the above process, the synthesis reaction formula of the modified toughening agent is as follows:

[0024]

[0025] The results of mass spectrometry analysis of white solid 1 are as follows: m / z: 1382.86 (100.0%), 1383.87 (89.7%), 1384.87 (43.4%), 1385.87 (14.4%), 1386.88 (2.5%), 1386.87 (1.5%); the results of mass spectrometry analysis of the modified toughening agent are as follows: m / z: 1720.02 (100.0%), 1719.02 (92.6%), 1721.03 (55.1%), 1722.03 (24.8%), 1723.03 (7.8%), 1721.02 (4.6%), 1720.03 (1.6%), 1724.04 (1.1%), 1724.03 (1.0%).

[0026] Preferably, in S1, the dosage ratio of 3,5-dihydroxybenzoic acid, castor oil, sulfolane and 4-dimethylaminopyridine is (20.2 - 26.1) g : (41 - 52.3) g : (50 - 75) mL : (0.42 - 0.54) g, the temperature for continuous reaction during heating is 170 - 190 °C, the reaction time is 6 - 8 h, washing is carried out with deionized water and xylene, and the drying temperature is 40 - 45 °C and the time is 6 - 8 h.

[0027] Preferably, in S2, the dosage ratio of white solid 1, epichlorohydrin, isopropyl alcohol and sodium hydroxide is (100.04 - 106.12) g : (35.2 - 38.8) g : (20 - 28) g : (1.2 - 2) g, the temperature for magnetic stirring reaction during heating is 50 - 55 °C, the temperature for continued heating is 65 - 68 °C, and the time for continued magnetic stirring reaction is 4 - 6 h.

[0028] The impact-resistant MPP power pipe prepared by using the preparation method of the impact-resistant MPP power pipe.

[0029] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are as follows:

[0030] 1. The present invention first uses erythritol, vanillin and furfurylamine as main raw materials to prepare a composite flame retardant, and then uses 3,5-dihydroxybenzoic acid, castor oil and epichlorohydrin as main raw materials to prepare a modified toughening agent. Adding the two to the preparation process of the MPP power pipe can effectively improve its flame retardancy, mechanical properties, chemical corrosion resistance and impact resistance.

[0031] 2. The modified flame retardant prepared in the present invention is added to the preparation process of MPP power pipes, which can effectively improve their flame retardancy and mechanical properties. The presence of the nitrogen-containing structure can decompose and release non-combustible gases such as NH3 and H2O under high-temperature conditions, expand the carbon layer and dilute oxygen, thereby enhancing the flame retardancy. The prepared modified flame retardant can form hydrogen bonds with polypropylene, strengthening the interfacial bonding force, and thus improving the mechanical properties of MPP power pipes.

[0032] 3. The modified toughening agent prepared in the present invention is added to the preparation process of MPP power pipes, which can effectively improve their impact resistance and chemical corrosion resistance. The long-chain fatty acids contained in castor oil form flexible side chains after esterification, playing an "internal plasticization" role in the MPP matrix, absorbing impact energy through molecular chain slip and reducing the brittleness of the material. The introduction of epoxy groups can form a dynamic crosslinking network with polypropylene chain segments, dissipating energy through reversible bond breakage-recombination under external force, further enhancing the toughness; at the same time, the modified toughening agent can bond chemically with MPP to reduce the molecular chain gap, hinder the penetration of corrosive media, and improve its chemical corrosion resistance. Specific embodiments

[0033] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0034] Example 1: This example discloses a preparation method of a modified flame retardant, which includes the following steps:

[0035] Q1: Add 5.05 g of erythritol to a mixed solution of 30 mL of N,N-dimethylformamide and 30 mL of petroleum ether, stir and mix to obtain Solution 1. Add 13.98 g of vanillin to a mixed solution of 15 mL of N,N-dimethylformamide and 15 mL of petroleum ether, stir and mix to obtain Solution 2. Then add Solution 1 and Solution 2 to a container, heat and stir at 55 °C for 30 min, then add 0.92 g of citric acid, raise the temperature to 120 °C and react for 16 h. After the reaction, cool, add the reacted solution to a sodium bicarbonate solution, precipitate, wash with deionized water and ethanol, and dry in vacuum to obtain Compound A;

[0036] Q2: Add 4.71 g of furfurylamine and 11 g of natural benzaldehyde to 50 mL of 1,4-dioxane, stir in an ice bath for 30 min, then add 9.8 g of compound A, continue to react in an ice bath for 2 h, then raise the temperature to 30 °C and react for 3 h. After the reaction is completed, under nitrogen protection, continue to raise the temperature to 90 °C and react for 12 h. After the reaction is completed, cool, filter, rotary evaporate, dissolve, wash, recrystallize, and vacuum dry to obtain the composite flame retardant.

[0037] This example discloses a preparation method of a modified toughening agent, which includes the following steps:

[0038] S1: Add 23.3 g of 3,5-dihydroxybenzoic acid, 45.8 g of castor oil, 62.5 mL of sulfolane, and 0.48 g of 4-dimethylaminopyridine to a reaction vessel, introduce nitrogen, raise the temperature to 180 °C and react continuously for 6 h. After the reaction is completed, cool, wash with deionized water and xylene, filter, and dry at 45 °C for 8 h to obtain white solid 1;

[0039] S2: Add 103.08 g of white solid 1, 36.9 g of epichlorohydrin, and 24 g of isopropanol to a container, introduce nitrogen, heat and stir magnetically at 55 °C, then continue to raise the temperature to 65 °C, then add 1.6 g of sodium hydroxide, and continue to stir magnetically for 6 h. After the reaction is completed, filter under reduced pressure, wash, filter, and vacuum dry to obtain the modified toughening agent.

[0040] This example discloses a preparation method of an impact-resistant MPP power pipe, which includes the following steps:

[0041] Step 1: Mix 70 g of polypropylene, 15 g of poly(trimethylene terephthalate), and 15 g of carbon fiber to obtain a base material;

[0042] Step 2: Add 1.5 g of modified flame retardant, 4 g of modified toughening agent, 3 g of compatibilizer, 2 g of coupling agent, 2 g of lubricant, and 0.75 g of antioxidant to 96 g of the base material in sequence, and stir and mix well to obtain a mixed material;

[0043] Step 3: Mix the mixed material using a high-speed mixer, then add it to a twin-screw extruder, extrude, cool and shape, cut, and polish to obtain the impact-resistant MPP power pipe.

[0044] Example 2: This example discloses a preparation method of a modified flame retardant, which includes the following steps:

[0045] Q1: Add 4.5 g of erythritol to a mixed solution of 30 mL of N,N-dimethylformamide and 30 mL of petroleum ether, stir and mix to obtain Solution 1. Add 13.13 g of vanillin to a mixed solution of 15 mL of N,N-dimethylformamide and 15 mL of petroleum ether, stir and mix to obtain Solution 2. Then add Solution 1 and Solution 2 to a container, heat and stir at 55 °C for 30 min. Subsequently, add 0.86 g of citric acid, raise the temperature to 120 °C and react for 16 h. After the reaction, cool down, add the reacted solution to a sodium bicarbonate solution to precipitate, wash with deionized water and ethanol, and dry in vacuum to obtain Compound A;

[0046] Q2: Add 4.34 g of furfurylamine and 10 g of natural benzaldehyde to 45 mL of 1,4-dioxane, stir in an ice bath for 30 min. Subsequently, add 9.2 g of Compound A, continue to react in an ice bath for 2 h, then raise the temperature to 30 °C and react for 3 h. After the reaction, under nitrogen protection, continue to raise the temperature to 90 °C and react for 12 h. After the reaction, cool down, filter, rotary evaporate, dissolve, wash, recrystallize, and dry in vacuum to obtain the composite flame retardant.

[0047] This example discloses a preparation method of a modified toughening agent, including the following steps:

[0048] S1: Add 20.2 g of 3,5-dihydroxybenzoic acid, 41 g of castor oil, 50 mL of sulfolane, and 0.42 g of 4-dimethylaminopyridine to a reaction vessel, introduce nitrogen, raise the temperature to 180 °C and react continuously for 6 h. After the reaction, cool down, wash with deionized water and xylene, filter, and dry at 45 °C for 8 h to obtain white solid 1;

[0049] S2: Add 100.04 g of white solid 1, 35.2 g of epichlorohydrin, and 20 g of isopropanol to a container, introduce nitrogen, heat and stir magnetically at 55 °C, then continue to raise the temperature to 65 °C, then add 1.2 g of sodium hydroxide, and continue to stir magnetically for 6 h. After the reaction, carry out vacuum filtration, wash, filter, and dry in vacuum to obtain the modified toughening agent.

[0050] This example discloses a preparation method of an impact-resistant MPP power pipe, including the following steps:

[0051] Step 1: Mix 60 g of polypropylene, 20 g of poly(trimethylene terephthalate), and 10 g of carbon fiber to obtain the base material;

[0052] Step 2: Add 1 g of modified flame retardant, 5 g of modified toughening agent, 4 g of compatibilizer, 1 g of coupling agent, 1 g of lubricant, and 0.5 g of antioxidant to 85 g of the base material in sequence, stir and mix thoroughly to obtain the mixed material;

[0053] Step 3: Mix the mixture using a high-speed mixer, then add it to a twin-screw extruder, extrude, cool and shape, cut, and polish to obtain the impact-resistant MPP power pipe.

[0054] Example 3: This example discloses a preparation method of a modified flame retardant, which includes the following steps:

[0055] Q1: Add 5.6 g of erythritol to a mixed solution of 30 mL of N,N-dimethylformamide and 30 mL of petroleum ether, stir and mix to obtain Solution 1. Add 14.25 g of vanillin to a mixed solution of 15 mL of N,N-dimethylformamide and 15 mL of petroleum ether, stir and mix to obtain Solution 2. Then add Solution 1 and Solution 2 to a container, heat and stir at 55 °C for 30 min, then add 0.98 g of citric acid, raise the temperature to 120 °C and react for 16 h. After the reaction, cool, add the reacted solution to a sodium bicarbonate solution to precipitate, wash with deionized water and ethanol, and dry in vacuum to obtain Compound A;

[0056] Q2: Add 5.13 g of furfurylamine and 12 g of natural benzaldehyde to 55 mL of 1,4-dioxane, stir in an ice bath for 30 min, then add 10.5 g of Compound A, continue to react in an ice bath for 2 h, then raise the temperature to 30 °C and react for 3 h. After the reaction, under nitrogen protection, continue to raise the temperature to 90 °C and react for 12 h. After the reaction, cool, filter, rotary evaporate, dissolve, wash, recrystallize, and dry in vacuum to obtain the composite flame retardant.

[0057] This example discloses a preparation method of a modified toughening agent, which includes the following steps:

[0058] S1: Add 26.1 g of 3,5-dihydroxybenzoic acid, 52.3 g of castor oil, 75 mL of sulfolane, and 0.54 g of 4-dimethylaminopyridine to a reaction vessel, introduce nitrogen, raise the temperature to 180 °C and react for 6 h. After the reaction, cool, wash with deionized water and xylene, filter, and dry at 45 °C for 8 h to obtain white solid 1;

[0059] S2: Add 106.12 g of white solid 1, 38.8 g of epichlorohydrin, and 28 g of isopropanol to a container, introduce nitrogen, heat and stir magnetically at 55 °C, then continue to raise the temperature to 65 °C, then add 2 g of sodium hydroxide, and continue to stir magnetically for 6 h. After the reaction, carry out vacuum filtration, wash, filter, and dry in vacuum to obtain the modified toughening agent.

[0060] This example discloses a preparation method of an impact-resistant MPP power pipe, which includes the following steps:

[0061] Step 1: 80 g of polypropylene, 10 g of polytrimethylene terephthalate and 20 g of carbon fiber are mixed to obtain a base material;

[0062] Step 2: Add 2g of modified flame retardant, 3g of modified toughening agent, 2g of compatibilizer, 3g of coupling agent, 3g of lubricant and 2g of antioxidant to 110g of base material in sequence, stir and mix thoroughly to obtain a mixture;

[0063] Step 3: Mix the mixture using a high-speed mixer, then add it to a twin-screw extruder, extrude it, cool it, cut it, and grind it to obtain an impact-resistant MPP power pipe.

[0064] Example 4: This example discloses a method for preparing a modified flame retardant, comprising the following steps:

[0065] Q1: 4.8 g of erythritol was added to a mixed solution of 30 mL of N, N-dimethylformamide and 30 mL of petroleum ether, and the mixture was stirred to obtain solution 1. 13.57 g of vanillin was added to a mixed solution of 15 mL of N, N-dimethylformamide and 15 mL of petroleum ether, and the mixture was stirred to obtain solution 2. Solution 1 and solution 2 were then added to a container, heated and stirred at 55° C. for 30 min, and then 0.88 g of citric acid was added, and the mixture was heated at 120° C. for 16 h. After the reaction was completed, the mixture was cooled, and the reaction solution was added to a sodium bicarbonate solution for precipitation, washed with deionized water and ethanol, and dried in vacuo to obtain compound A.

[0066] Q2: Add 4.48g furfurylamine and 10.5g natural benzaldehyde to 48mL 1,4-dioxane, stir in an ice bath for 30min, then add 9.6g compound A, continue to react in an ice bath for 2h, then heat to 30℃ and react for 3h. After the reaction, continue to heat to 90℃ and react for 12h under nitrogen protection. After the reaction, cool, filter, rotary evaporate, dissolve, wash, recrystallize, and vacuum dry to obtain a composite flame retardant.

[0067] This embodiment discloses a method for preparing a modified toughening agent, comprising the following steps:

[0068] S1: 21.9 g of 3,5-dihydroxybenzoic acid, 42 g of castor oil, 55 mL of cyclopentane and 0.45 g of 4-dimethylaminopyridine were added to a reaction container, nitrogen was introduced, the temperature was raised to 180°C and the reaction was continued for 6 h. After the reaction was completed, the mixture was cooled, washed with deionized water and xylene, filtered, and dried at 45°C for 8 h to obtain a white solid 1;

[0069] S2: Add 102.21 g of white solid 1, 35.8 g of epichlorohydrin, and 22 g of isopropanol into a container, introduce nitrogen, heat and stir magnetically at 55°C for reaction, then continue to raise the temperature to 65°C, then add 1.4 g of sodium hydroxide, continue to stir magnetically for 6 h. After the reaction is completed, perform suction filtration under reduced pressure, wash, filter, and dry in vacuum to obtain the modified toughening agent.

[0070] This example discloses a preparation method of an impact-resistant MPP power pipe, including the following steps:

[0071] Step 1: Mix 72 g of polypropylene, 12 g of poly(trimethylene terephthalate), and 12 g of carbon fiber to obtain the base material;

[0072] Step 2: Sequentially add 1.2 g of modified flame retardant, 3.5 g of modified toughening agent, 2.5 g of compatibilizer, 1.5 g of coupling agent, 1.5 g of lubricant, and 0.6 g of antioxidant to 90 g of the base material, and stir and mix thoroughly to obtain the mixed material;

[0073] Step 3: Mix the mixed material using a high-speed mixer, then add it to a twin-screw extruder, extrude, cool and shape, cut, and polish to obtain the impact-resistant MPP power pipe.

[0074] Example 5: This example discloses a preparation method of a modified flame retardant, including the following steps:

[0075] Q1: Add 5.2 g of erythritol into a mixed solution of 30 mL of N,N-dimethylformamide and 30 mL of petroleum ether, stir and mix to obtain Solution 1. Add 14.03 g of vanillin into a mixed solution of 15 mL of N,N-dimethylformamide and 15 mL of petroleum ether, stir and mix to obtain Solution 2. Then add Solution 1 and Solution 2 into a container, heat and stir at 55°C for 30 min, then add 0.94 g of citric acid, raise the temperature to 120°C for reaction for 16 h. After the reaction is completed, cool, add the reacted solution into a sodium bicarbonate solution for precipitation, wash with deionized water and ethanol, and dry in vacuum to obtain Compound A;

[0076] Q2: Add 4.67 g of furfurylamine and 11.5 g of natural benzaldehyde into 52 mL of 1,4-dioxane, stir magnetically in an ice bath for 30 min, then add 10.1 g of Compound A, continue to react in an ice bath for 2 h, then raise the temperature to 30°C for reaction for 3 h. After the reaction is completed, under nitrogen protection, continue to raise the temperature to 90°C for reaction for 12 h. After the reaction is completed, cool, filter, perform rotary evaporation, dissolve, wash, recrystallize, and dry in vacuum to obtain the composite flame retardant.

[0077] This example discloses a preparation method of a modified toughening agent, including the following steps:

[0078] S1: Add 24.7 g of 3,5-dihydroxybenzoic acid, 48 g of castor oil, 60 mL of sulfolane, and 0.52 g of 4-dimethylaminopyridine into a reaction vessel, introduce nitrogen, heat up to 180 °C and react for 6 h. After the reaction is completed, cool it, wash with deionized water and xylene, filter, and dry at 45 °C for 8 h to obtain white solid 1;

[0079] S2: Add 105.18 g of white solid 1, 37.8 g of epichlorohydrin, and 26 g of isopropanol into a container, introduce nitrogen, heat and stir magnetically at 55 °C for reaction, then continue to heat up to 65 °C, then add 1.8 g of sodium hydroxide, and continue to stir magnetically for reaction for 6 h. After the reaction is completed, carry out vacuum filtration, washing, filtration, and vacuum drying to obtain a modified toughening agent.

[0080] This example discloses a preparation method of an impact-resistant MPP power pipe, including the following steps:

[0081] Step 1: Mix 68 g of polypropylene, 18 g of poly(trimethylene terephthalate), and 18 g of carbon fiber to obtain a base material;

[0082] Step 2: Add 1.6 g of a modified flame retardant, 4.5 g of a modified toughening agent, 3.5 g of a compatibilizer, 2.5 g of a coupling agent, 2.5 g of a lubricant, and 0.7 g of an antioxidant to 100 g of the base material in sequence, and stir and mix well to obtain a mixed material;

[0083] Step 3: Mix the mixed material using a high-speed mixer, then add it to a twin-screw extruder, extrude, cool and shape, cut, and polish to obtain an impact-resistant MPP power pipe.

[0084] Example 6: This example discloses a preparation method of a modified flame retardant, including the following steps:

[0085] Q1: Add 5.15 g of erythritol into a mixed solution of 30 mL of N,N-dimethylformamide and 30 mL of petroleum ether, stir and mix to obtain solution 1. Add 13.71 g of vanillin into a mixed solution of 15 mL of N,N-dimethylformamide and 15 mL of petroleum ether, stir and mix to obtain solution 2. Then add solution 1 and solution 2 into a container, heat and stir at 55 °C for 30 min, then add 0.9 g of citric acid, heat up to 120 °C and react for 16 h. After the reaction is completed, cool it, add the reacted solution into a sodium bicarbonate solution to precipitate, wash with deionized water and ethanol, and vacuum dry to obtain compound A;

[0086] Q2: Add 5.01 g of furfurylamine and 10.2 g of natural benzaldehyde to 49 mL of 1,4-dioxane, stir in an ice bath for 30 min, then add 10.3 g of compound A, continue the reaction in an ice bath for 2 h, then raise the temperature to 30 °C and react for 3 h. After the reaction is completed, under nitrogen protection, continue to raise the temperature to 90 °C and react for 12 h. After the reaction is completed, cool, filter, rotary evaporate, dissolve, wash, recrystallize, and vacuum dry to obtain the composite flame retardant.

[0087] This example discloses a preparation method of a modified toughening agent, including the following steps:

[0088] S1: Add 25.2 g of 3,5-dihydroxybenzoic acid, 51.6 g of castor oil, 72 mL of sulfolane, and 0.46 g of 4-dimethylaminopyridine to a reaction vessel, introduce nitrogen, raise the temperature to 180 °C and react for 6 h. After the reaction is completed, cool, wash with deionized water and xylene, filter, and dry at 45 °C for 8 h to obtain white solid 1;

[0089] S2: Add 104.36 g of white solid 1, 38.1 g of epichlorohydrin, and 25 g of isopropanol to a container, introduce nitrogen, heat and stir magnetically at 55 °C, then continue to raise the temperature to 65 °C, then add 1.5 g of sodium hydroxide, and continue to stir magnetically for 6 h. After the reaction is completed, carry out vacuum filtration, washing, filtering, and vacuum drying to obtain the modified toughening agent.

[0090] This example discloses a preparation method of an impact-resistant MPP power pipe, including the following steps:

[0091] Step 1: Mix 78 g of polypropylene, 16 g of poly(trimethylene terephthalate), and 17 g of carbon fiber to obtain the base material;

[0092] Step 2: Add 1.8 g of modified flame retardant, 3.8 g of modified toughening agent, 2.8 g of compatibilizer, 2.2 g of coupling agent, 2.8 g of lubricant, and 0.9 g of antioxidant to 102 g of the base material in sequence, stir and mix thoroughly to obtain the mixed material;

[0093] Step 3: Mix the mixed material using a high-speed mixer, then add it to a twin-screw extruder, extrude, cool and shape, cut, and polish to obtain the impact-resistant MPP power pipe.

[0094] Comparative Example 1: Compared with Example 1, in the process of preparing the impact-resistant MPP power pipe in Comparative Example 1, the modified flame retardant is not added, and other conditions remain unchanged.

[0095] Comparative Example 2: Compared with Example 1, in the process of preparing the impact-resistant MPP power pipe in Comparative Example 2, the modified toughening agent is not added, and other conditions remain unchanged.

[0096] Experimental Example: The impact-resistant MPP power pipes prepared in Examples 1-6 and Comparative Examples 1-2 were subjected to performance tests. The combustion performance of the samples was tested according to GB / T 2408-2021, the tensile performance of the samples was tested according to GB / T 8804.1-2003, the corrosion resistance performance of the samples was tested according to GB / T 11547-2008, and the impact resistance performance of the samples was tested according to GB / T 14152-2001. The test results are shown in Table 1:

[0097] Table 1

[0098] Project Vertical burning rating Elongation at break / % Mass reduction rate / % Impact height / m Example 1 V-0 275.7 0.36 2.06 Example 2 V-0 274.6 0.46 2.01 Example 3 V-0 274.9 0.41 2.02 Example 4 V-0 275.1 0.43 1.98 Example 5 V-0 274.3 0.39 1.99 Example 6 V-0 274.3 0.45 2.02 Comparative example 1 V-2 243.6 0.46 2.01 Comparative example 2 V-0 274.5 0.98 1.53

[0099] It can be seen from the test results in Table 1 that the MPP power pipes prepared in Examples 1-6 of the present invention have excellent flame retardancy, mechanical properties, corrosion resistance and impact resistance. By comparing Comparative Example 1 with Examples 1-6, it can be seen that adding a modified flame retardant can effectively improve the flame retardancy and mechanical properties of the MPP power pipe; by comparing Comparative Example 2 with Examples 1-6, it can be seen that adding a modified toughening agent can effectively improve the corrosion resistance and impact resistance of the MPP power pipe.

[0100] As described above, only the preferred specific embodiments of the present invention are provided, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent substitutions or changes, should be covered by the protection scope of the present invention.

[0101] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the present invention to only the specific embodiments. Obviously, many modifications and changes can be made according to the content of this specification. These embodiments are selected and specifically described in this specification to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and utilize the present invention well. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A preparation method of an impact-resistant MPP power pipe, characterized in that, It includes the following steps: Step 1: Mix polypropylene, polytrimethylene terephthalate and carbon fiber to obtain a base material; Step 2: Sequentially add a modified flame retardant, a modified toughening agent, a compatibilizer, a coupling agent, a lubricant and an antioxidant to the base material, and fully stir and mix to obtain a mixed material; Step 3: Mix the mixed material using a high-speed mixer, then add it to a twin-screw extruder, extrude, cool and shape, cut and polish to obtain an impact-resistant MPP power pipe; In the said Step 1, the dosage ratio of polypropylene, polytrimethylene terephthalate and carbon fiber is (60 - 80) g : (10 - 20) g : (10 - 20) g; in the said Step 2, the dosage ratio of the base material, the modified flame retardant, the modified toughening agent, the compatibilizer, the coupling agent, the lubricant and the antioxidant is (85 - 110) g : (1 - 2) g : (3 - 5) g : (2 - 4) g : (1 - 3) g : (1 - 3) g : (0.5 - 1) g; The preparation method of the said modified flame retardant includes the following steps: Q1: Add erythritol to a mixed solution of N,N-dimethylformamide and petroleum ether, stir and mix to obtain Solution 1, add vanillin to a mixed solution of N,N-dimethylformamide and petroleum ether, stir and mix to obtain Solution 2, then add Solution 1 and Solution 2 to a container, heat and stir, then add citric acid, raise the temperature for reaction, after the reaction ends, cool, add the reacted solution to a sodium bicarbonate solution, precipitate, wash, and vacuum dry to obtain Compound A; Q2: Add furfurylamine and natural benzaldehyde to 1,4-dioxane, stir in an ice bath, then add Compound A, continue to react in an ice bath, then raise the temperature for reaction, after the reaction ends, under nitrogen protection, continue to raise the temperature for reaction, after the reaction ends, cool, filter, rotary evaporate, dissolve, wash, recrystallize, and vacuum dry to obtain a composite flame retardant; The preparation method of the said modified toughening agent includes the following steps: S1: Add 3,5-dihydroxybenzoic acid, castor oil, sulfolane and 4-dimethylaminopyridine to a reaction vessel, introduce nitrogen, raise the temperature and continue to react, after the reaction ends, cool, wash, filter, and dry to obtain White Solid 1; S2: Add White Solid 1, epichlorohydrin and isopropyl alcohol to a container, introduce nitrogen, heat and stir magnetically for reaction, then continue to raise the temperature, then add sodium hydroxide, continue to stir magnetically for reaction, after the reaction ends, carry out vacuum filtration, wash, filter, and vacuum dry to obtain a modified toughening agent.

2. The preparation method of an impact-resistant MPP power pipe according to claim 1, characterized in that, In the said Q1, the dosage ratio of erythritol, vanillin and citric acid is (4.5 - 5.6) g : (13.13 - 14.25) g : (0.86 - 0.98) g, the heating and stirring temperature is 50 - 55 °C, the stirring time is 30 - 45 min, the temperature for the temperature-raising reaction is 110 - 130 °C, the reaction time is 14 - 18 h, and wash with deionized water and ethanol.

3. The preparation method of an impact-resistant MPP power pipe according to claim 1, characterized in that, In Q2, the dosage ratio of furfurylamine, natural benzaldehyde, 1,4-dioxane and compound A is (4.34 - 5.13) g : (10 - 12) g : (45 - 55) mL : (9.2 - 10.5) g. The ice bath stirring time is 30 - 45 min, the continued ice bath reaction time is 1 - 2 h, the heating reaction temperature is 25 - 30 °C, the reaction time is 2 - 3 h, the continued heating reaction temperature is 90 - 95 °C, and the reaction time is 10 - 12 h.

4. The preparation method of an impact-resistant MPP power pipe according to claim 1, characterized in that, In S1, the dosage ratio of 3,5-dihydroxybenzoic acid, castor oil, sulfolane and 4-dimethylaminopyridine is (20.2 - 26.1) g : (41 - 52.3) g : (50 - 75) mL : (0.42 - 0.54) g. The continued heating reaction temperature is 170 - 190 °C, the reaction time is 6 - 8 h, it is washed with deionized water and xylene, and the drying temperature is 40 - 45 °C, and the time is 6 - 8 h.

5. The preparation method of an impact-resistant MPP power pipe according to claim 1, characterized in that, In S2, the dosage ratio of white solid 1, epichlorohydrin, isopropanol and sodium hydroxide is (100.04 - 106.12) g : (35.2 - 38.8) g : (20 - 28) g : (1.2 - 2) g. The heating magnetic stirring reaction temperature is 50 - 55 °C, the continued heating temperature is 65 - 68 °C, and the continued magnetic stirring reaction time is 4 - 6 h.

6. An impact-resistant MPP power pipe prepared by the method according to any one of claims 1 - 5.

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