Impact-resistant MPP electric power tube and preparation method thereof

Abstract

The invention discloses an anti-impact MPP power tube and a preparation method thereof, and belongs to the technical field of power tube preparation. The preparation method of the impact-resistant MPP electric power tube comprises the following steps: step 1, mixing polypropylene, polytrimethylene terephthalate and carbon fibers to obtain a base material; 2, sequentially adding the modified flame retardant, the modified flexibilizer, the compatilizer, the coupling agent, the lubricant and the antioxidant into the base material, and fully stirring and mixing to obtain a mixture; and step 3, mixing the mixture by using a high-speed mixer, then adding the mixture into a twin-screw extruder, and carrying out extrusion molding, cooling shaping, cutting and polishing to obtain the impact-resistant MPP electric power tube. The MPP electric power tube prepared by the method has excellent flame retardant property, mechanical property, chemical corrosion resistance and impact resistance.

Description

Technical Field

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

[0002] With the rapid development of modern cities and industries, the laying and maintenance of power pipelines have become a key link in infrastructure construction. Power pipelines not only need to withstand various pressures from the ground, but also need to cope with complex and changeable underground environments, such as acidic and alkaline soils, humid conditions, and temperature changes. Traditional power pipes, such as PE pipes, are easily deformed under high temperatures or external forces, which seriously affects the laying and maintenance of cables. Especially in high temperature environments, the strength of PE pipes will be significantly reduced, which brings great safety hazards to the laying of cables 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 made of polypropylene as the base material and modified by a special formula. They have many 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 and effectively prevent electrical accidents such as leakage and short circuit. At the same time, MPP power pipes also have good flexibility and can be bent according to construction requirements, making them easy to lay 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 ingredients 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 of montmorillonite and talcum powder in a weight ratio of 1:3-1:5. The MPP power pipe prepared by the MPP power pipe material of the invention has strong impact resistance, good flame retardancy, high mechanical strength, good heat resistance, excellent comprehensive performance, and stable processing and molding. However, the flame retardancy, mechanical properties, chemical corrosion resistance, and impact resistance of the MPP power pipe material prepared by this method still have room for improvement. Summary of the invention

[0005] The object of the present invention is to provide an impact-resistant MPP power pipe and a preparation method thereof, so as 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] In order to achieve the above object, the present invention adopts the following technical solutions: The present invention provides a method for preparing an impact-resistant MPP power pipe, comprising the following steps: Step 1: Mix polypropylene, polytrimethylene terephthalate and carbon fiber to obtain a base material; Step 2: Adding modified flame retardant, modified toughening agent, compatibilizer, coupling agent, lubricant and antioxidant to the base material in sequence, stirring and mixing thoroughly to obtain a mixture; 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.

[0007] Preferably, in the step one, the amount ratio of polypropylene, polytrimethylene terephthalate and carbon fiber is (60-80) g: (10-20) g: (10-20) g; in the step two, the amount ratio of base material, modified flame retardant, modified toughening agent, compatibilizer, coupling agent, lubricant and antioxidant is (85-110) g: (1-2) g: (3-5) g: (2-4) g: (1-3) g: (1-3) g: (0.5-1) g.

[0008] Preferably, the method for preparing the modified flame retardant comprises 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 into a container, heat and stir, then add citric acid, heat and react, after the reaction is completed, cool, add the reacted solution into 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 the ice bath reaction, then increase the temperature to react. After the reaction is completed, continue to increase the temperature under nitrogen protection. After the reaction is completed, cool, filter, rotary evaporate, dissolve, wash, recrystallize, and vacuum dry to obtain a composite flame retardant.

[0009] In the above process, the synthetic reaction formula of the composite flame retardant is as follows:

[0010] The results of mass spectrometry analysis of compound A were: 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 were: m / z: 936.36 (100.0%), 937.37 (63.7%), 938.37 (22.0%), 939.37 (5.4%).

[0011] 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 heating reaction temperature is 110-130°C, the reaction time is 14-18 h, and the product is washed with deionized water and ethanol.

[0012] Preferably, in Q2, the dosage ratio of furfural, 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 ice bath reaction time is continued for 1-2 h, the heating reaction temperature is 25-30 ° C, the reaction time is 2-3 h, the heating reaction temperature is continued to be 90-95 ° C, and the reaction time is 10-12 h.

[0013] Preferably, the method for preparing the modified toughening agent comprises the following steps: S1: 3,5-dihydroxybenzoic acid, castor oil, cyclopentane sulfone and 4-dimethylaminopyridine were added to a reaction vessel, nitrogen was introduced, the temperature was increased and the reaction was continued, and after the reaction was completed, the reaction was cooled, washed, filtered and dried to obtain a white solid 1; S2: Add white solid 1, epichlorohydrin and isopropanol into a container, introduce nitrogen, heat and magnetically stir to react, then continue to heat, then add sodium hydroxide, continue to magnetically stir to react, after the reaction is completed, reduce pressure and filter, wash, filter, and vacuum dry to obtain a modified toughening agent.

[0014] In the above process, the synthetic reaction formula of the modified toughening agent is as follows:

[0015] The results of mass spectrometry analysis of the white solid 1 were: 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 were: 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%).

[0016] Preferably, in S1, the dosage ratio of 3,5-dihydroxybenzoic acid, castor oil, cyclopentane sulfone and 4-dimethylaminopyridine is (20.2-26.1) g: (41-52.3) g: (50-75) mL: (0.42-0.54) g, the temperature of the continuous reaction is 170-190°C, the reaction time is 6-8h, the reaction is washed with deionized water and xylene, the drying temperature is 40-45°C, and the time is 6-8h.

[0017] Preferably, in S2, the dosage ratio of the 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 4-6h.

[0018] The impact-resistant MPP power pipe is prepared by the method for preparing the impact-resistant MPP power pipe.

[0019] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 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 retardant properties, mechanical properties, chemical corrosion resistance and impact resistance.

[0020] 2. The modified flame retardant prepared in the present invention is added to the preparation process of the MPP power pipe, which can effectively improve its flame retardant and mechanical properties. The presence of the nitrogen-containing structure can decompose and release NH under high temperature conditions. 3 , H 2 O and other non-flammable gases can expand the carbon layer and dilute the oxygen, thereby improving the flame retardant properties. The prepared modified flame retardant can form hydrogen bonds with polypropylene, enhance the interfacial bonding force, and thus improve the mechanical properties of the MPP power pipe.

[0021] 3. The prepared modified toughening agent is added to the preparation process of the MPP power pipe in the present invention, which can effectively improve its impact resistance and chemical corrosion resistance. The long-chain fatty acids contained in castor oil form flexible side chains after esterification, which play an "internal plasticizing" role in the MPP matrix, absorb impact energy through molecular chain slippage, and reduce the brittleness of the material. The introduction of epoxy groups can form a dynamic cross-linking network with the polypropylene segment, which can dissipate energy through reversible bond breaking and recombination under the action of external force, and further improve toughness; at the same time, the modified toughening agent can chemically bond with MPP to reduce the molecular chain gap, hinder the penetration of corrosive media, and improve its chemical corrosion resistance. DETAILED DESCRIPTION

[0022] The following will be described clearly and completely in conjunction with the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Example 1: This example discloses a method for preparing a modified flame retardant, comprising the following steps: Q1: 5.05 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. 13.98 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 0.92 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. Q2: Add 4.71g furfurylamine and 11g natural benzaldehyde to 50mL 1,4-dioxane, stir in an ice bath for 30min, then add 9.8g 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.

[0024] This embodiment discloses a method for preparing a modified toughening agent, comprising the following steps: S1: 23.3 g of 3,5-dihydroxybenzoic acid, 45.8 g of castor oil, 62.5 mL of cyclopentane and 0.48 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; S2: Add 103.08g of white solid 1, 36.9g of epichlorohydrin and 24g of isopropanol into a container, introduce nitrogen, heat to 55°C with magnetic stirring to react, then continue to raise the temperature to 65°C, then add 1.6g of sodium hydroxide, continue to react with magnetic stirring for 6h, after the reaction is completed, reduce pressure and filter, wash, filter, and vacuum dry to obtain a modified toughening agent.

[0025] This embodiment discloses a method for preparing an impact-resistant MPP power pipe, comprising the following steps: Step 1: Mix 70g of polypropylene, 15g of polytrimethylene terephthalate and 15g of carbon fiber to obtain a base material; 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 base material in sequence, stir and mix thoroughly to obtain a mixture; 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.

[0026] Example 2: This example discloses a method for preparing a modified flame retardant, comprising the following steps: Q1: 4.5 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. 13.13 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 0.86 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. Q2: Add 4.34g furfurylamine and 10g natural benzaldehyde to 45mL 1,4-dioxane, stir in an ice bath for 30min, then add 9.2g 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.

[0027] This embodiment discloses a method for preparing a modified toughening agent, comprising the following steps: S1: 20.2 g of 3,5-dihydroxybenzoic acid, 41 g of castor oil, 50 mL of sulfolane and 0.42 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; S2: Add 100.04g of white solid 1, 35.2g of epichlorohydrin and 20g of isopropanol into a container, introduce nitrogen, heat to 55°C with magnetic stirring to react, then continue to raise the temperature to 65°C, then add 1.2g of sodium hydroxide, continue to react with magnetic stirring for 6h, after the reaction is completed, reduce pressure and filter, wash, filter, and vacuum dry to obtain a modified toughening agent.

[0028] This embodiment discloses a method for preparing an impact-resistant MPP power pipe, comprising the following steps: Step 1: Mix 60g of polypropylene, 20g of polytrimethylene terephthalate and 10g of carbon fiber to obtain a base material; 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 base material in sequence, stir and mix thoroughly to obtain a mixture; 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.

[0029] Example 3: This example discloses a method for preparing a modified flame retardant, comprising the following steps: Q1: 5.6 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. 14.25 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 0.98 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. Q2: Add 5.13g furfurylamine and 12g natural benzaldehyde to 55mL 1,4-dioxane, stir in an ice bath for 30min, then add 10.5g 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.

[0030] This embodiment discloses a method for preparing a modified toughening agent, comprising the following steps: S1: 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 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; S2: Add 106.12g of white solid 1, 38.8g of epichlorohydrin and 28g of isopropanol into a container, introduce nitrogen, heat to 55°C with magnetic stirring to react, then continue to raise the temperature to 65°C, then add 2g of sodium hydroxide, continue to react with magnetic stirring for 6h, after the reaction is completed, reduce pressure and filter, wash, filter, and vacuum dry to obtain a modified toughening agent.

[0031] This embodiment discloses a method for preparing an impact-resistant MPP power pipe, comprising the following steps: Step 1: 80 g of polypropylene, 10 g of polytrimethylene terephthalate and 20 g of carbon fiber are mixed to obtain a base material; 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; 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.

[0032] Example 4: This example discloses a method for preparing a modified flame retardant, comprising the following steps: 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. 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.

[0033] This embodiment discloses a method for preparing a modified toughening agent, comprising the following steps: 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; S2: Add 102.21g of white solid 1, 35.8g of epichlorohydrin and 22g of isopropanol into a container, introduce nitrogen, heat to 55°C with magnetic stirring to react, then continue to raise the temperature to 65°C, then add 1.4g of sodium hydroxide, continue to react with magnetic stirring for 6h, after the reaction is completed, reduce pressure and filter, wash, filter, and vacuum dry to obtain a modified toughening agent.

[0034] This embodiment discloses a method for preparing an impact-resistant MPP power pipe, comprising the following steps: Step 1: Mix 72g of polypropylene, 12g of polytrimethylene terephthalate and 12g of carbon fiber to obtain a base material; Step 2: 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 base material in sequence, stir and mix thoroughly to obtain a mixture; 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.

[0035] Example 5: This example discloses a method for preparing a modified flame retardant, comprising the following steps: Q1: 5.2 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. 14.03 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 0.94 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. Q2: Add 4.67g furfurylamine and 11.5g natural benzaldehyde to 52mL 1,4-dioxane, stir in an ice bath for 30min, then add 10.1g 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.

[0036] This embodiment discloses a method for preparing a modified toughening agent, comprising the following steps: S1: 24.7 g of 3,5-dihydroxybenzoic acid, 48 g of castor oil, 60 mL of sulfolane and 0.52 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 hours. After the reaction was completed, the mixture was cooled, washed with deionized water and xylene, filtered, and dried at 45°C for 8 hours to obtain a white solid 1; S2: Add 105.18g of white solid 1, 37.8g of epichlorohydrin and 26g of isopropanol into a container, introduce nitrogen, heat to 55°C with magnetic stirring to react, then continue to raise the temperature to 65°C, then add 1.8g of sodium hydroxide, continue to react with magnetic stirring for 6h, after the reaction is completed, reduce pressure and filter, wash, filter, and vacuum dry to obtain a modified toughening agent.

[0037] This embodiment discloses a method for preparing an impact-resistant MPP power pipe, comprising the following steps: Step 1: Mix 68g of polypropylene, 18g of polytrimethylene terephthalate and 18g of carbon fiber to obtain a base material; Step 2: Add 1.6 g of modified flame retardant, 4.5 g of modified toughening agent, 3.5 g of compatibilizer, 2.5 g of coupling agent, 2.5 g of lubricant and 0.7 g of antioxidant to 100 g of base material in sequence, stir and mix thoroughly to obtain a mixture; 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.

[0038] Example 6: This example discloses a method for preparing a modified flame retardant, comprising the following steps: Q1: 5.15 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. 13.71 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 0.9 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. Q2: Add 5.01g furfurylamine and 10.2g natural benzaldehyde to 49mL 1,4-dioxane, stir in an ice bath for 30min, then add 10.3g 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.

[0039] This embodiment discloses a method for preparing a modified toughening agent, comprising the following steps: S1: 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 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; S2: Add 104.36g of white solid 1, 38.1g of epichlorohydrin and 25g of isopropanol into a container, introduce nitrogen, heat to 55°C with magnetic stirring to react, then continue to raise the temperature to 65°C, then add 1.5g of sodium hydroxide, continue to react with magnetic stirring for 6h, after the reaction is completed, reduce pressure and filter, wash, filter, and vacuum dry to obtain a modified toughening agent.

[0040] This embodiment discloses a method for preparing an impact-resistant MPP power pipe, comprising the following steps: Step 1: Mix 78g of polypropylene, 16g of polytrimethylene terephthalate and 17g of carbon fiber to obtain a base material; 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 base material in sequence, stir and mix thoroughly to obtain a mixture; 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.

[0041] Comparative Example 1: Compared with Example 1, in the process of preparing the impact-resistant MPP power pipe in Comparative Example 1, no modified flame retardant is added, and other conditions remain unchanged.

[0042] Comparative Example 2: Compared with Example 1, in the process of preparing the impact-resistant MPP power pipe in Comparative Example 2, no modified toughening agent is added, and other conditions remain unchanged.

[0043] 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 of the samples was tested according to GB / T 11547-2008, and the impact resistance of the samples was tested according to GB / T 14152-2001. The test results are shown in Table 1: Table 1 project Vertical burning level 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 From the test results in Table 1, it can be seen 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. From the comparison between Comparative Example 1 and 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; from the comparison between Comparative Example 2 and 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.

[0044] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

[0045] 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 invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for preparing an impact-resistant MPP power pipe, characterized in that: The following steps are involved: Step 1: Mix polypropylene, polytrimethylene terephthalate and carbon fiber to obtain a base material; Step 2: Adding modified flame retardant, modified toughening agent, compatibilizer, coupling agent, lubricant and antioxidant to the base material in sequence, stirring and mixing thoroughly to obtain a mixture; 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.

2. The method for preparing an impact-resistant MPP power pipe according to claim 1, characterized in that: In the step 1, the usage ratio of polypropylene, polytrimethylene terephthalate and carbon fiber is (60-80) g: (10-20) g: (10-20) g; in the step 2, the usage ratio of base material, modified flame retardant, modified toughening agent, compatibilizer, coupling agent, lubricant and antioxidant is (85-110) g: (1-2) g: (3-5) g: (2-4) g: (1-3) g: (1-3) g: (0.5-1) g.

3. The method for preparing an impact-resistant MPP power pipe according to claim 1, characterized in that: The preparation method of the modified flame retardant comprises 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 into a container, heat and stir, then add citric acid, heat and react, after the reaction is completed, cool, add the reacted solution into 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 the ice bath reaction, then increase the temperature to react. After the reaction is completed, continue to increase the temperature under nitrogen protection. After the reaction is completed, cool, filter, rotary evaporate, dissolve, wash, recrystallize, and vacuum dry to obtain a composite flame retardant.

4. The method for preparing an impact-resistant MPP power pipe according to claim 3, characterized in that: In the 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 heating reaction temperature is 110-130°C, the reaction time is 14-18 h, and the product is washed with deionized water and ethanol.

5. The method for preparing an impact-resistant MPP power pipe according to claim 3, characterized in that: In Q2, the dosage ratio of furfural, 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 ice bath reaction time is continued for 1-2 h, the heating reaction temperature is 25-30°C, the reaction time is 2-3 h, the heating reaction temperature is continued to be 90-95°C, and the reaction time is 10-12 h.

6. The method for preparing an impact-resistant MPP power pipe according to claim 1, characterized in that: The preparation method of the modified toughening agent comprises the following steps: S1: 3,5-dihydroxybenzoic acid, castor oil, cyclopentane sulfone and 4-dimethylaminopyridine were added to a reaction vessel, nitrogen was introduced, the temperature was increased and the reaction was continued, and after the reaction was completed, the reaction was cooled, washed, filtered and dried to obtain a white solid 1; S2: Add white solid 1, epichlorohydrin and isopropanol into a container, introduce nitrogen, heat and magnetically stir to react, then continue to heat, then add sodium hydroxide, continue to magnetically stir to react, after the reaction is completed, reduce pressure and filter, wash, filter, and vacuum dry to obtain a modified toughening agent.

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

8. The method for preparing an impact-resistant MPP power pipe according to claim 6, characterized in that: In the S2, the dosage ratio of the 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 4-6h.

9. An impact-resistant MPP power pipe prepared by the method according to any one of claims 1 to 8.

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