A high-strength MPP pipe and production method thereof

Abstract

The present invention relates to the technical field of polymer material preparation, and discloses a high-strength MPP pipe and a production method thereof. The MPP pipe comprises the following raw materials: polypropylene resin, antioxidant, lubricant; and also comprises a functional composition, a heat dissipation and flame retardant additive. The present invention participates in the preparation process of the MPP pipe by preparing the functional composition and the heat dissipation and flame retardant additive, so that the prepared MPP pipe has excellent mechanical strength, impact resistance, wear resistance, and additional excellent heat dissipation function and flame retardant performance, can be used in a variety of special environments, and can also play a heat dissipation effect during the current output process, reduce the risk of fire, and produce a flame retardant effect when a fire occurs, effectively protect life and property safety, and have a long service life.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, and in particular to a high-strength MPP pipe and a production method thereof. Background Art

[0002] MPP pipe, also known as power cable protection pipe, is a pipe with modified polypropylene (MPP) as the main raw material. Compared with traditional PP pipe, MPP pipe has higher heat deformation temperature, excellent low temperature resistance and corrosion resistance. It is widely used in power cable and communication cable protection pipe and other fields. However, in actual use, the strength of MPP pipe is not enough. In complex engineering environments, the interface of MPP pipe is easy to break, and the impact resistance and wear resistance are not strong. When used in special environments such as wind, sand, hail, etc., it is easy to be scratched and scratched, and cracks will appear in severe cases, affecting the service life of the pipe. In addition, ordinary MPP pipe has poor heat dissipation and no flame retardant properties. During the power transportation process, the thermal effect of the current can easily lead to pipe aging, affecting the strength of the pipe. There is also a risk of causing fire, which brings great safety hazards.

[0003] Therefore, in order to improve the safety of power transportation, people usually modify MPP pipes when using them. For example, the patent with publication number CN112358686B discloses a method for preparing a special MPP material containing a three-dimensional mesh structure thermal conductive material and its power cable sheath pipe. The patent uses a three-dimensional mesh structure combined with a resin material to form a complete thermal conductive channel, has good thermal conductivity, and can also maintain the original mechanical properties. It has a very broad development prospect. However, although the patent enhances the heat dissipation function of the MPP pipe and reduces the risk of fire, it does not improve the mechanical strength, and the patent does not have a flame retardant effect. When a fire occurs, the MPP pipe produces molten droplets, which will cause the fire to spread and threaten life and property safety. Summary of the invention

[0004] The purpose of the present invention is to provide a high-strength MPP pipe and a production method thereof, which solves the following technical problems: (1) The strength of the MPP pipe is not high, and it is easily affected by the environment and external forces during use, causing breakage and damage; (2) The heat dissipation and flame retardant properties of the MPP pipe are poor, which can easily cause fire to spread and affect safety.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A high-strength MPP pipe comprises the following raw materials in parts by weight: 80-100 parts of polypropylene resin, 2-5 parts of antioxidant, 1-3 parts of lubricant; and also comprises 20-25 parts of functional composition and 8-10 parts of heat dissipation and flame retardant additive.

[0007] Furthermore, the antioxidant is any one of 3,5-di-tert-butyl-4-hydroxybenzaldehyde and 3,5-di-tert-butyl-4-hydroxycinnamic acid; and the lubricant is any one of stearic acid, calcium stearate and zinc stearate.

[0008] Furthermore, the preparation method of the functional composition comprises the following steps:

[0009] S1: placing the EPDM rubber in a torque rheometer, setting the speed to 80-90 r / min and the temperature to 160-170° C., adding initiator and 1,6-heptadien-4-ol, reacting for 8-10 minutes and then discharging the material to obtain a mixture;

[0010] S2: placing the mixture in xylene, heating it to 65-85° C., stirring it thoroughly to dissolve it, adding a precipitant to precipitate and remove impurities, filtering and washing it, and drying it to obtain the modified EPDM rubber;

[0011] S3: Place the modified EPDM rubber in toluene, stir thoroughly for 2 hours, add the barium chloride solution, ultrasonically disperse for 20-30 minutes, then add the ferrous sulfate solution, let stand for 2 hours, remove the solvent by rotary evaporation, and collect the product to obtain a functional composition.

[0012] Through the above technical scheme, under the action of an initiator, the alkenyl groups in the structure of EPDM rubber and the two alkenyl groups in the structure of 1,6-heptadien-4-ol undergo free radical polymerization reaction to form a cross-linked structure, and after impurities are removed, a cross-linked modified EPDM rubber having multiple hydroxyl groups is obtained, and the divalent barium ions are fixed in the cross-linked structure of the EPDM rubber through complexation between the hydroxyl groups and the divalent barium ions in the barium chloride solution, and then a barium sulfate precipitate is generated through a double replacement reaction between sulfate ions in the ferrous sulfate solution and barium ions, thereby obtaining a functional composition containing barium sulfate in the structure. This functional composition uses EPDM rubber as a matrix and has good compatibility with the matrix material of the MPP pipe. EPDM rubber can enhance the toughness of the pipe. The cross-linked structure can buffer stress changes when the pipe is impacted, absorb impact energy, and improve the impact resistance of the pipe. The embedded barium sulfate can be evenly dispersed in the pipe, significantly improving the wear resistance and mechanical strength of the pipe, so that the prepared MPP pipe has the characteristics of high strength and high impact resistance, is not easy to be damaged during transportation, and is not easy to break during use. Even under long-term wind and sand erosion, it can maintain excellent performance and has a long service life.

[0013] Furthermore, in step S1, the initiator is any one of benzoyl peroxide and dicumyl peroxide.

[0014] Furthermore, in step S2, the precipitant is anhydrous ethanol.

[0015] Furthermore, in step S3, the mass fraction of the barium chloride solution is 10-12%; the mass fraction of the ferrous sulfate solution is 12-15%.

[0016] Furthermore, the method for preparing the heat dissipating flame retardant additive comprises the following steps:

[0017] SS1: Add hexagonal boron nitride, 4-amino-1-butanol, zirconium oxide ball milling beads and sodium hydroxide solution into a ball mill, mix and ball mill at a speed of 300-400 rpm for 8-10 hours, sieve to remove the ball milling beads, add hydrochloric acid solution dropwise until the pH is neutral, filter, wash and dry to obtain modified boron nitride;

[0018] SS2: Place the modified boron nitride in dimethyl sulfoxide, add diethylphosphoacetic acid and a catalyst after ultrasonic dispersion for 10 minutes, heat to 180°C and react for 8-10 hours, filter, wash and dry to obtain a heat dissipating flame retardant additive.

[0019] Through the above technical scheme, a mechanical ball milling method is adopted, and the interaction between the amino group in the structure of 4-amino-1-butanol and the boron atom in hexagonal boron nitride is utilized to peel off the hexagonal boron nitride sheet, and active hydroxyl groups are introduced on its surface to obtain modified boron nitride. Under the action of a catalyst, the active hydroxyl groups coated on the surface of the modified boron nitride react with the carboxyl groups in the structure of diethylphosphoacetic acid to obtain a heat dissipation flame retardant additive. The heat dissipation flame retardant additive is coated with a layer of organic matter on the surface, which can be evenly dispersed in the base material of the MPP pipe. With hexagonal boron nitride as the base material, the wear resistance and mechanical strength of the MPP pipe can be significantly enhanced, and the heat dissipation performance of the MPP pipe can be improved. When it is applied to the fields of power cables, it can disperse the heat brought by the current output, delay the aging time, reduce the temperature of the pipe surface, and reduce the risk of fire. At the same time, the diethylphosphoacetic acid introduced on its surface has excellent flame retardant properties, which can prevent the pipe from melting and dripping when a fire occurs, causing the fire to spread, play a flame retardant role, and effectively protect life and property safety.

[0020] Furthermore, in step SS1, the concentration of the sodium hydroxide solution is 1.5-2 mol / L, and the concentration of the hydrochloric acid solution is 1-2 mol / L.

[0021] Furthermore, in step SS2, the catalyst is p-toluenesulfonic acid.

[0022] A method for producing a high-strength MPP pipe comprises the following steps:

[0023] Step 1: Place parts by weight of polypropylene resin, functional composition, heat dissipation and flame retardant additive, antioxidant and lubricant in a high-speed mixer, set the speed to 500-600 r / min, stir for 2-4 hours, and obtain a mixture;

[0024] Step 2: Transfer the mixture to a twin-screw extruder, set the screw speed to 250-300r / min, the temperature of zone 1 to 110-130°C, the temperature of zone 2 to 130-150°C, the temperature of zone 3 to 190-220°C, the temperature of zone 4 to 180-190°C, and the temperature of zone 5 to 160-170°C, and perform melt extrusion granulation to obtain the MPP pipe matrix material.

[0025] Beneficial effects of the present invention:

[0026] The present invention prepares a functional composition and heat dissipation and flame retardant additives to participate in the preparation process of MPP pipes, so that the prepared MPP pipes have a tensile strength of up to 56MPa and an impact strength of up to 11.4KJ / m 2 The thermal conductivity reaches 1.45W / m·k, the flame retardant grade reaches V-0, and it also has excellent wear resistance and scratch resistance, long service life and high safety, and can adapt to the application requirements of power cable pipes in a variety of complex environments.

[0027] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0029] Figure 1 The infrared spectra of EPDM rubber, modified EPDM rubber and functional composition in the embodiment of the present invention;

[0030] Figure 2 This is an infrared spectrum of the heat dissipation and flame retardant additive in the embodiment of the present invention. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe 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.

[0032] In the following embodiments and comparative examples of the present invention, the preparation methods of the functional compositions and heat dissipating flame retardant additives used are as follows:

[0033] 1. Preparation of functional composition

[0034] S1: 6 g of EPDM rubber was placed in a torque rheometer, the speed was set to 80 r / min, the temperature was set to 160° C., 0.5 g of benzoyl peroxide and 5 g of 1,6-heptadien-4-ol were added, and the mixture was discharged after reacting for 8 min to obtain a mixed material;

[0035] S2: placing the mixture in 200 ml xylene, heating to 65° C., stirring thoroughly to dissolve it, adding 20 ml anhydrous ethanol to precipitate and remove impurities, filtering, washing, and drying to obtain modified EPDM rubber;

[0036] S3: 6 g of modified EPDM rubber was placed in 50 ml of toluene, and after being fully stirred for 2 h, it was added to 20 ml of 10% barium chloride solution, ultrasonically dispersed for 20 min, and then added to 30 ml of 12% ferrous sulfate solution. After standing for 2 h, the solvent was removed by rotary evaporation, and the product was collected to obtain a functional composition.

[0037] The infrared characterization of EPDM rubber, modified EPDM rubber and functional composites was carried out using the potassium bromide tablet method. The results are shown in Figure 1 In the infrared spectrum of EPDM rubber, 3054cm -1 The absorption peak of the carbon-hydrogen bond in the olefin group is 2921 cm -1 The absorption peak of carbon-hydrogen bond in methyl group is at 3324cm -1 The absorption peak of hydroxyl group is at 3054cm -1 The absorption peak of the carbon-hydrogen bond in the alkenyl group at 1100 cm-1 is significantly reduced, indicating that the alkenyl group in the EPDM rubber structure and the alkenyl group in the 1,6-heptadien-4-ol structure undergo free radical polymerization. In the infrared spectrum of the functional composite, compared with the modified EPDM rubber, the absorption peak at 1100 cm-1 is significantly reduced. -1 The stretching vibration peak of the sulfur-oxygen bond in barium sulfate appears at 756 cm -1 The bending vibration peak of the sulfur-oxygen bond in barium sulfate appears at 534 cm -1 The absorption peak of barium oxygen bond appears at , indicating that barium sulfate is introduced into the modified EPDM rubber to obtain a functional composite.

[0038] 2. Preparation of heat dissipation and flame retardant additives

[0039] SS1: Add 5 g of hexagonal boron nitride, 8 g of 4-amino-1-butanol, 100 g of zirconium oxide ball milling beads and 40 ml of 1.5 mol / L sodium hydroxide solution in a ball mill, mix and ball mill at a speed of 300 rpm for 8 h, sieve to remove the ball milling beads, add 1 mol / L hydrochloric acid solution dropwise until the pH is neutral, filter, wash and dry to obtain modified boron nitride;

[0040] SS2: 5 g of modified boron nitride was placed in 100 ml of dimethyl sulfoxide, 4 g of diethylphosphoacetic acid and 0.3 g of p-toluenesulfonic acid were added, the temperature was raised to 180°C for reaction for 8 h, and the heat dissipation and flame retardant additive was obtained after filtering, washing and drying.

[0041] The heat dissipation and flame retardant additive was characterized by infrared using potassium bromide tableting method. The results are shown in Figure 2 ,Depend on Figure 2 It can be seen that 1371cm -1 The absorption peak of nitrogen-boron bond is 1245cm -1 The absorption peak of the phosphorus-oxygen double bond in the phosphate group is 3023 cm -1 The absorption peak of the carbon-hydrogen bond in the benzene ring is 1721 cm -1 The absorption peak of the carbon-oxygen double bond in the ester group is at 1721cm -1 The appearance of the carbon-oxygen double bond absorption peak in the ester group indicates that an esterification reaction occurred between the hydroxyl group on the surface of the modified boron nitride and the carboxyl group in the diethylphosphinoacetic acid structure.

[0042] Example 1

[0043] An MPP pipe comprises the following raw materials in parts by weight: 80 parts of polypropylene resin, 20 parts of functional composition, 8 parts of heat dissipation and flame retardant additive, 2 parts of 3,5-di-tert-butyl-4-hydroxybenzaldehyde, and 1 part of stearic acid;

[0044] The preparation method of the MPP pipe comprises the following steps:

[0045] Step 1: Place parts by weight of polypropylene resin, functional composition, heat dissipation and flame retardant additive, 3,5-di-tert-butyl-4-hydroxybenzaldehyde, and stearic acid in a high-speed mixer, set the speed to 500 r / min, and stir for 2 hours to obtain a mixture;

[0046] Step 2: Transfer the mixture to a twin-screw extruder, set the screw speed to 250 r / min, the temperature of zone 1 to 110°C, the temperature of zone 2 to 130°C, the temperature of zone 3 to 190°C, the temperature of zone 4 to 180°C, the temperature of zone 5 to 160°C, melt extrude and granulate to obtain MPP pipe.

[0047] Example 2

[0048] An MPP pipe comprises the following raw materials in parts by weight: 90 parts of polypropylene resin, 23 parts of functional composition, 9 parts of heat dissipation and flame retardant additive, 4 parts of 3,5-di-tert-butyl-4-hydroxycinnamic acid, and 2 parts of calcium stearate;

[0049] The preparation method of the MPP pipe comprises the following steps:

[0050] Step 1: Place parts by weight of polypropylene resin, functional composition, heat dissipation and flame retardant additive, 3,5-di-tert-butyl-4-hydroxycinnamic acid, and calcium stearate in a high-speed mixer, set the speed to 550 r / min, and stir for 3 hours to obtain a mixture;

[0051] Step 2: Transfer the mixture to a twin-screw extruder, set the screw speed to 270 r / min, the temperature of zone 1 to 120°C, the temperature of zone 2 to 140°C, the temperature of zone 3 to 200°C, the temperature of zone 4 to 185°C, the temperature of zone 5 to 165°C, melt extrude and granulate to obtain MPP pipe.

[0052] Example 3

[0053] An MPP pipe comprises the following raw materials in parts by weight: 100 parts of polypropylene resin, 25 parts of a functional composition, 10 parts of a heat dissipation and flame retardant additive, 5 parts of 3,5-di-tert-butyl-4-hydroxybenzaldehyde, and 3 parts of zinc stearate;

[0054] The preparation method of the MPP pipe comprises the following steps:

[0055] Step 1, placing parts by weight of polypropylene resin, functional composition, heat dissipation and flame retardant additive, 3,5-di-tert-butyl-4-hydroxybenzaldehyde, and zinc stearate in a high-speed mixer, setting the speed to 600 r / min, and stirring for 4 hours to obtain a mixture;

[0056] Step 2: Transfer the mixture to a twin-screw extruder, set the screw speed to 300 r / min, the temperature of zone 1 to 130°C, the temperature of zone 2 to 150°C, the temperature of zone 3 to 220°C, the temperature of zone 4 to 190°C, the temperature of zone 5 to 170°C, melt extrude and granulate to obtain MPP pipe.

[0057] Comparative Example 1

[0058] An MPP pipe comprises the following raw materials in parts by weight: 90 parts of polypropylene resin, 9 parts of heat dissipation and flame retardant additive, 4 parts of 3,5-di-tert-butyl-4-hydroxycinnamic acid, and 2 parts of calcium stearate;

[0059] The preparation method of the MPP pipe comprises the following steps:

[0060] Step 1, placing parts by weight of polypropylene resin, heat dissipation and flame retardant additive, 3,5-di-tert-butyl-4-hydroxycinnamic acid, and calcium stearate in a high-speed mixer, setting the speed to 550 r / min, and stirring for 3 hours to obtain a mixture;

[0061] Step 2: Transfer the mixture to a twin-screw extruder, set the screw speed to 270 r / min, the temperature of zone 1 to 120°C, the temperature of zone 2 to 140°C, the temperature of zone 3 to 200°C, the temperature of zone 4 to 185°C, the temperature of zone 5 to 165°C, melt extrude and granulate to obtain MPP pipe.

[0062] Comparative Example 2

[0063] An MPP pipe comprises the following raw materials in parts by weight: 90 parts of polypropylene resin, 23 parts of a functional composition, 4 parts of 3,5-di-tert-butyl-4-hydroxycinnamic acid, and 2 parts of calcium stearate;

[0064] The preparation method of the MPP pipe comprises the following steps:

[0065] Step 1: Place parts by weight of polypropylene resin, functional composition, 3,5-di-tert-butyl-4-hydroxycinnamic acid and calcium stearate in a high-speed mixer, set the speed to 550 r / min, and stir for 3 hours to obtain a mixture;

[0066] Step 2: Transfer the mixture to a twin-screw extruder, set the screw speed to 270 r / min, the temperature of zone 1 to 120°C, the temperature of zone 2 to 140°C, the temperature of zone 3 to 200°C, the temperature of zone 4 to 185°C, the temperature of zone 5 to 165°C, melt extrude and granulate to obtain MPP pipe.

[0067] Comparative Example 3

[0068] An MPP pipe comprises the following raw materials in parts by weight: 90 parts of polypropylene resin, 4 parts of 3,5-di-tert-butyl-4-hydroxycinnamic acid, and 2 parts of calcium stearate;

[0069] The preparation method of the MPP pipe comprises the following steps:

[0070] Step 1: Place parts by weight of polypropylene resin, 3,5-di-tert-butyl-4-hydroxycinnamic acid, and calcium stearate in a high-speed mixer, set the speed to 550 r / min, and stir for 3 hours to obtain a mixture;

[0071] Step 2: Transfer the mixture to a twin-screw extruder, set the screw speed to 270 r / min, the temperature of zone 1 to 120°C, the temperature of zone 2 to 140°C, the temperature of zone 3 to 200°C, the temperature of zone 4 to 185°C, the temperature of zone 5 to 165°C, melt extrude and granulate to obtain MPP pipe.

[0072] Comparative Example 4

[0073] An MPP pipe comprises the following raw materials in parts by weight: 90 parts of polypropylene resin, 23 parts of EPDM rubber, 9 parts of heat dissipation and flame retardant additive, 4 parts of 3,5-di-tert-butyl-4-hydroxycinnamic acid, and 2 parts of calcium stearate;

[0074] The preparation method of the MPP pipe comprises the following steps:

[0075] Step 1, placing parts by weight of polypropylene resin, EPDM rubber, heat dissipation and flame retardant additives, 3,5-di-tert-butyl-4-hydroxycinnamic acid, and calcium stearate in a high-speed mixer, setting the speed to 550 r / min, and stirring for 3 hours to obtain a mixture;

[0076] Step 2: Transfer the mixture to a twin-screw extruder, set the screw speed to 270 r / min, the temperature of zone 1 to 120°C, the temperature of zone 2 to 140°C, the temperature of zone 3 to 200°C, the temperature of zone 4 to 185°C, the temperature of zone 5 to 165°C, melt extrude and granulate to obtain MPP pipe.

[0077] Comparative Example 5

[0078] An MPP pipe comprises the following raw materials in parts by weight: 90 parts of polypropylene resin, 23 parts of a functional composition, 9 parts of hexagonal boron nitride, 4 parts of 3,5-di-tert-butyl-4-hydroxycinnamic acid, and 2 parts of calcium stearate;

[0079] The preparation method of the MPP pipe comprises the following steps:

[0080] Step 1: Place parts by weight of polypropylene resin, functional composition, hexagonal boron nitride, 3,5-di-tert-butyl-4-hydroxycinnamic acid, and calcium stearate in a high-speed mixer, set the speed to 550 r / min, and stir for 3 hours to obtain a mixture;

[0081] Step 2: Transfer the mixture to a twin-screw extruder, set the screw speed to 270 r / min, the temperature of zone 1 to 120°C, the temperature of zone 2 to 140°C, the temperature of zone 3 to 200°C, the temperature of zone 4 to 185°C, the temperature of zone 5 to 165°C, melt extrude and granulate to obtain MPP pipe.

[0082] Performance Testing

[0083] The MPP pipes prepared in Examples 1 to 3 and Comparative Examples 1 to 5 were cut into samples that met the specifications using a universal prototype machine, and the samples were subjected to a tensile strength test according to the reference standard GB / T1040-2006; the samples were subjected to an impact strength test according to the reference standard GB / T1043.1-2008; the thermal conductivity of the samples was tested according to the reference standard GB / T3399-1982 to determine the heat dissipation performance of the samples; the samples were subjected to a vertical combustion test according to the reference standard UL-94 to determine the flame retardant performance of the samples; the samples were placed on the sample table of a GSL-46 steel wool abrasion tester, a 1000g load weight was placed on top, the samples were rubbed back and forth at a rate of 15mm / s, and 50 cycles were repeated. After the end, the scratches on the sample surface were observed, and the samples were subjected to a wear resistance test; the specific test results are shown in the following table:

[0084]

[0085] It can be seen from the above table that the samples prepared in Examples 1 to 3 all have excellent mechanical strength, wear resistance, impact resistance, heat dissipation and flame retardant properties. The sample prepared in Comparative Example 1 does not have the functional composition added, so the mechanical strength, impact resistance and wear resistance are not as good as those in the examples, but the heat dissipation and flame retardant additives are added therein, and the sample has a high level of heat dissipation and flame retardant properties. The sample prepared in Comparative Example 2 does not have the heat dissipation and flame retardant additives added therein, and has poor heat dissipation and flame retardant properties, but because the functional composition is added therein, the impact resistance and wear resistance are at a relatively excellent level. The sample prepared in Comparative Example 3 has neither the functional composition nor the heat dissipation and flame retardant added therein. The additives have poor mechanical strength, wear resistance, impact resistance, heat dissipation and flame retardancy. The sample prepared in Comparative Example 4 is directly added with EPDM rubber without any improvement. The prepared sample has general mechanical strength, wear resistance and impact resistance, but heat dissipation and flame retardancy additives are added thereto, so the sample has excellent heat dissipation and flame retardancy. The sample prepared in Comparative Example 5 is directly added with hexagonal boron nitride. Although the functional composition is also added thereto, the sample has poor mechanical strength, wear resistance, impact resistance, heat dissipation and flame retardancy. This is because the unmodified hexagonal boron nitride is agglomerated in the matrix material.

[0086] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0087] The above contents are merely examples and explanations of the concept of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the scope defined by the concept of the invention, they should all fall within the protection scope of the present invention.

Claims

1. A high-strength MPP pipe, comprising the following raw materials in parts by weight: 80-100 parts of polypropylene resin, 2-5 parts of antioxidant, and 1-3 parts of lubricant; characterized in that: It also includes 20-25 parts of a functional composition and 8-10 parts of a heat dissipating and flame retardant additive; The method for preparing the functional composition comprises the following steps: S1: placing EPDM rubber in a torque rheometer, setting the speed to 80-90 r / min, the temperature to 160-170° C., adding initiator and 1,6-heptadien-4-ol, reacting for 8-10 min, and then discharging to obtain a mixture; the initiator is any one of benzoyl peroxide and diisopropylbenzene peroxide; S2: placing the mixture in xylene, heating it to 65-85°C, stirring it thoroughly to dissolve it, adding a precipitant to precipitate and remove impurities, filtering, washing, and drying to obtain the modified EPDM rubber; the precipitant is anhydrous ethanol; S3: placing the modified EPDM rubber in toluene, stirring for 2 hours, adding the barium chloride solution, ultrasonically dispersing for 20-30 minutes, and then adding the ferrous sulfate solution. After standing for 2 hours, the solvent is removed by rotary evaporation, and the product is collected to obtain a functional composition; the mass fraction of the barium chloride solution is 10-12%; the mass fraction of the ferrous sulfate solution is 12-15%; The preparation method of the heat dissipating flame retardant additive comprises the following steps: SS1: Add hexagonal boron nitride, 4-amino-1-butanol, zirconium oxide ball milling beads and sodium hydroxide solution into a ball mill, mix and ball mill at a speed of 300-400 rpm for 8-10 hours, sieve to remove the ball milling beads after the end, add hydrochloric acid solution dropwise until the pH is neutral, filter, wash and dry to obtain modified boron nitride; the concentration of the sodium hydroxide solution is 1.5-2 mol / L, and the concentration of the hydrochloric acid solution is 1-2 mol / L; SS2: Place the modified boron nitride in dimethyl sulfoxide, add diethylphosphoacetic acid and a catalyst after ultrasonic dispersion for 10 minutes, heat to 180°C for reaction for 8-10 hours, filter, wash and dry to obtain a heat dissipating flame retardant additive; the catalyst is p-toluenesulfonic acid.

2. A high-strength MPP pipe according to claim 1, characterized in that: The antioxidant is any one of 3,5-di-tert-butyl-4-hydroxybenzaldehyde and 3,5-di-tert-butyl-4-hydroxycinnamic acid; the lubricant is any one of stearic acid, calcium stearate and zinc stearate.

3. A method for producing a high-strength MPP pipe according to claim 1, characterized in that: The production method comprises the following steps: Step 1: Place parts by weight of polypropylene resin, functional composition, heat dissipation and flame retardant additive, antioxidant and lubricant in a high-speed mixer, set the speed to 500-600 r / min, stir for 2-4 hours, and obtain a mixture; Step 2: Transfer the mixture to a twin-screw extruder, set the screw speed to 250-300r / min, the temperature of zone 1 to 110-130°C, the temperature of zone 2 to 130-150°C, the temperature of zone 3 to 190-220°C, the temperature of zone 4 to 180-190°C, and the temperature of zone 5 to 160-170°C, and perform melt extrusion granulation to obtain MPP pipes.

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