PE pipe and preparation method thereof

Abstract

The invention relates to the technical field of PE pipes, in particular to a PE pipe and a preparation method thereof. The PE pipe is prepared from, by weight, 40-60 parts of polyethylene, 6-8 parts of filler, 4-6 parts of auxiliaries, 4-6 parts of silicon dioxide, 2-4 parts of stabilizer and 2-4 parts of antioxidant. According to the invention, the filler is added in the preparation process of the PE pipe, and the coconut shell forms a porous carbon structure after being carbonized and ground, so that the interface bonding force between the materials can be effectively enhanced, and the coconut shell is uniformly dispersed in a PE matrix to bear part of external force and play a role in structure enhancement; thiomolybdate ions generated by thioacetamide and sodium molybdate can uniformly precipitate and grow on the surface and in pores of the coconut shell powder, and are tightly combined with the coconut shell powder, so that the structural stability of the PE pipe is effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of PE pipes, and specifically provides a PE pipe and a preparation method thereof. Background Art

[0002] PE pipes are pipe materials made from polyethylene resin as the main raw material and adding various additives. They are suitable for transporting various liquids and gases, are convenient for construction and installation, and are relatively light in weight, reducing the transportation and construction difficulties.

[0003] In the prior art, PE pipes are prepared using polyethylene as the main raw material. Due to the relatively weak intermolecular force and limited crystallinity of ordinary PE molecular chains, their inherent strength is insufficient. When subjected to relatively large pressure and tensile force, their molecular chains are prone to slip and break, affecting the strength performance of the pipes. Based on this, the present invention provides a PE pipe and a preparation method thereof. Summary of the Invention

[0004] The purpose of the present invention is to provide a PE pipe and a preparation method thereof. The PE pipe prepared by the present invention not only has good tensile strength and flexural strength performance, but also has excellent impact strength performance, effectively improving the service performance of the PE pipe.

[0005] To achieve the above purpose, the present invention provides the following technical solutions: In the first aspect, the present invention provides a PE pipe, which comprises the following raw materials in parts by weight: 40 - 60 parts of polyethylene, 6 - 8 parts of filler, 4 - 6 parts of additive, 4 - 6 parts of silicon dioxide, 2 - 4 parts of stabilizer, and 2 - 4 parts of antioxidant; The polyethylene is divided into component A raw material and component B raw material. Among them, the mass ratio of component A raw material to component B raw material is 1:0.2. Component A raw material is selected as high-density polyethylene, and component B raw material is selected as maleic anhydride grafted modified polyethylene; The raw material of the filler consists of coconut shell, diatomite, additive, and bamboo fiber powder, and the mass ratio of each raw material is 1:(1.2 - 1.4):(0.6 - 0.8):(0.2 - 0.4); The raw material of the additive consists of polyethylene terephthalate, polycarbonate, polybutylene terephthalate, and talcum powder, and the mass ratio of each raw material is 1:(0.2 - 0.3):(0.1 - 0.2):(0.02 - 0.03).

[0006] Further, the pretreatment method of the coconut shell is as follows: the coconut shell is crushed, and the crushing particle size is 2 - 10 mm. Then it is sent into an oven, and the oven is set to dry at 100 - 120°C for 40 - 50 min. After the drying treatment is completed, it is sent into a carbonization furnace for carbonization treatment. The carbonization furnace is set with a heating rate of 10 - 20°C / min and heated to 550 - 650°C. The obtained product is added into a reaction kettle, and a potassium hydroxide solution is added into the reaction kettle. The reaction kettle is set to be heated to 100 - 120°C, and the stirring speed is 120 - 160 r / min. It is kept warm and stirred for 1 - 3 h, and nitrogen is introduced during the treatment process. The obtained product is rinsed with deionized water, then sent into an oven, and the oven is set to dry at 80 - 100°C. The obtained product is ground, and the grinding particle size is 10 - 30 μm, thus completing the pretreatment of the coconut shell.

[0007] Further, the mass concentration of the potassium hydroxide solution is 30 - 50%, and the mass of the potassium hydroxide solution is 20 - 30% of the mass of the coconut shell.

[0008] Further, the additive is prepared by the following method: thioacetamide and sodium molybdate are added into deionized water, and the mixture is heated in a water bath to 80 - 90°C and kept warm and stirred for 20 - 30 min. After the treatment is completed, absolute ethanol and carbon nitride nanosheets are added, and the temperature is raised to 90 - 100°C and kept warm and stirred for 10 - 16 min. After the treatment is completed, concentrated hydrochloric acid is added, and it is set to be kept warm and react at 80 - 90°C for 10 - 16 min. The obtained product is washed with deionized water until the pH value is 6 - 7, then sent into an oven, and it is set to dry at 160 - 200°C for 2 - 4 h. Then it is set to be heated to 300 - 400°C and kept warm in a nitrogen atmosphere for 40 - 60 min. The obtained product is ground, and the grinding particle size is 10 - 30 μm, thus preparing the additive.

[0009] Further, the mass ratio of thioacetamide, sodium molybdate and deionized water is 1:(0.4 - 0.6):(20 - 30), the mass of absolute ethanol is 6 - 8 times the mass of thioacetamide, the mass of carbon nitride nanosheets is 10 - 20% of the mass of thioacetamide, and the mass of concentrated hydrochloric acid is 60 - 80% of the mass of thioacetamide.

[0010] Further, the filler is prepared by the following method: The additive and deionized water are added into a mixer. The mass of the deionized water is 70-80% of the mass of the additive. The mixer is set to stir at 200-300 r / min for 6-10 min. Then, diatomite and bamboo fiber powder are added in sequence. The mixer is set to stir at 300-400 r / min for 20-30 min. The obtained product is left to stand and age for 2-4 d. Then, it is sent into a centrifuge. The centrifuge is set to centrifuge at 2000-4000 r / min for 6-10 min. The supernatant is discarded. The obtained precipitate is washed with deionized water. The obtained product is sent into an oven and dried at 100-120 °C for 12-16 min to obtain the filler.

[0011] Further, the auxiliary agent is prepared by the following method: Polyethylene terephthalate and polycarbonate are added into a mixer. Component B raw material and polybutylene terephthalate are added into the mixer. The mixer is set to stir at 200-300 r / min for 10-20 min. Then, talcum powder is added. The mixer is set to stir at 300-400 r / min for 10-20 min to obtain the auxiliary agent.

[0012] Further, the silicon dioxide is selected as nano-silicon dioxide particles with a particle size of 10-50 nm.

[0013] Further, the stabilizer is selected from any one of diisooctyl phthalate and dioctyl phthalate, and the antioxidant is selected from any one of antioxidant 1076, antioxidant 168, and antioxidant 3114.

[0014] In the second aspect, the present invention also provides a preparation method of PE pipes, including the following steps: S1: Weigh the component A raw material, filler, auxiliary agent, silicon dioxide, stabilizer, and antioxidant as required and add them into a mixer. The mixer is set to stir at 600-800 r / min for 20-30 min to obtain the first mixture. S2: The first mixture is added into a mixer. The mixer is set to mix at 220-240 °C for 1-2 h to obtain the second mixture. S3: The second mixture is added into a twin-screw extruder. The temperature is set to 200-220 °C for extrusion molding to obtain a PE long pipe. After cooling, sizing, and cutting, the PE pipes are obtained.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. In the present invention, during the preparation process of PE pipes, fillers are added. Among them, after the coconut shell is carbonized and ground, a porous carbon structure is formed, which can effectively enhance the interfacial bonding force between materials, enabling it to be evenly dispersed in the PE matrix, bear part of the external force, and play a role in strengthening the structure. Through the addition of additives in the filler, the thiomolybdate ions generated by thioacetamide and sodium molybdate can be evenly precipitated and grown on the surface and pores of the coconut shell powder, forming a relatively tight bond with the coconut shell powder, effectively improving the structural stability of the PE pipes.

[0016] 2. In the present invention, during the preparation process of PE pipes, additives are added. Among them, by utilizing the high modulus characteristics of polyethylene terephthalate and the creep resistance and high toughness characteristics of polycarbonate, polyethylene terephthalate provides a high-strength framework, which is rigid and flexible complementary with polycarbonate to form a stable complementary structure. The anhydride group of maleic anhydride undergoes an ester exchange reaction with the ester group of polyethylene terephthalate, reducing the interfacial tension and further improving the overall strength performance of the PE pipes. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 FIG. is a flowchart of a PE pipe and its preparation method proposed by the invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. 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 protection scope of the present invention.

[0019] It should be noted that the raw materials used in the following embodiments are all commercially available raw materials.

[0020] Example 1:

[0021] It includes the following raw materials in parts by weight: 40 parts of polyethylene, 6 parts of filler, 4 parts of additive, 4 parts of silica, 2 parts of stabilizer, and 2 parts of antioxidant; The polyethylene is divided into A component raw material and B component raw material. Among them, the mass ratio of the A component raw material to the B component raw material is 1:0.2. The A component raw material is selected as high-density polyethylene, and the B component raw material is selected as maleic anhydride grafted modified polyethylene; The raw materials of the filler are composed of coconut shell, diatomite, additive, and bamboo fiber powder, and the mass ratio of each raw material is 1:(1.2):(0.6):(0.2); The raw materials of the additive are composed of polyethylene terephthalate, polycarbonate, polybutylene terephthalate, and talcum powder, and the mass ratio of each raw material is 1:(0.2):(0.1):(0.02).

[0022] The pretreatment method of coconut shell is as follows: The coconut shell is crushed to a particle size of 2 mm, and then sent into an oven. The oven is set at 100 °C for drying treatment for 40 min. After the drying treatment is completed, it is sent into a carbonization furnace for carbonization treatment. The carbonization furnace is set with a heating rate of 10 °C / min and heated to 550 °C. The obtained product is added into a reaction kettle, and potassium hydroxide solution is added into the reaction kettle. The reaction kettle is set to be heated to 100 °C, the stirring speed is 120 r / min, and it is kept stirring for 1 h. Nitrogen is introduced during the treatment process. The obtained product is washed with deionized water, and then sent into an oven. The oven is set at 80 °C for drying treatment. The obtained product is ground to a particle size of 10 μm, and the pretreatment of the coconut shell is completed.

[0023] The mass concentration of the potassium hydroxide solution is 30%, and the mass of the potassium hydroxide solution is 20% of the mass of the coconut shell.

[0024] The additive is prepared by the following method: Thioacetamide and sodium molybdate are added into deionized water, and the mixture is heated in a water bath to 80 °C and kept stirring for 20 min. After the treatment is completed, absolute ethanol and carbon nitride nanosheets are added, and the temperature is raised to 90 °C and kept stirring for 10 min. After the treatment is completed, concentrated hydrochloric acid is added, and it is set to be kept at 80 °C for reaction for 10 min. The obtained product is washed with deionized water until the pH value is 6, and then sent into an oven. It is set at 160 °C for drying treatment for 2 h, and then the temperature is raised to 300 °C and kept in a nitrogen atmosphere for 40 min. The obtained product is ground to a particle size of 10 μm to prepare the additive.

[0025] The mass ratio of thioacetamide, sodium molybdate and deionized water is 1:(0.4):(20). The mass of absolute ethanol is 6 times the mass of thioacetamide. The mass of carbon nitride nanosheets is 10% of the mass of thioacetamide. The mass of concentrated hydrochloric acid is 60% of the mass of thioacetamide.

[0026] The filler is prepared by the following method: The additive and deionized water are added into a mixer. The mass of deionized water is 70% of the mass of the additive. The mixer is set to stir at 200 r / min for 6 min, and then diatomite and bamboo fiber powder are added in sequence. The mixer is set to stir at 300 r / min for 20 min. The obtained product is left to age for 2 d, and then sent into a centrifuge. The centrifuge is set to centrifuge at 2000 r / min for 6 min, and the supernatant is discarded. The obtained precipitate is washed with deionized water, and the obtained product is sent into an oven. It is set at 100 °C for drying treatment for 12 min to prepare the filler.

[0027] The auxiliary agent is prepared by the following method: Polyethylene terephthalate and polycarbonate are added into a mixing machine, and the raw material of component B and polybutylene terephthalate are added into the mixing machine. The mixing machine is set to stir at 200 r / min for 10 min, then talcum powder is added, and the mixing machine is set to stir at 300 r / min for 10 min to obtain the auxiliary agent.

[0028] The silicon dioxide selected is nano-silicon dioxide particles with a particle size of 10 nm.

[0029] The stabilizer selected is diisooctyl phthalate, and the antioxidant selected is antioxidant 1076.

[0030] S1: Weigh the raw material of component A, filler, auxiliary agent, silicon dioxide, stabilizer and antioxidant as required and add them into a mixing machine. The mixing machine is set to stir at 600 r / min for 20 min to obtain the first mixture. S2: The first mixture is added into a kneading machine, and the kneading machine is set to knead at 220 °C for 1 h to obtain the second mixture. S3: The second mixture is added into a twin-screw extruder, and is extruded and formed at a set temperature of 200 °C to obtain a PE long tube. After cooling, sizing and cutting, the PE pipe is obtained.

[0031] Example 2:

[0032] It includes the following raw materials in parts by weight: 50 parts of polyethylene, 7 parts of filler, 5 parts of auxiliary agent, 5 parts of silicon dioxide, 3 parts of stabilizer, 3 parts of antioxidant; The polyethylene is divided into the raw material of component A and the raw material of component B. Among them, the mass ratio of the raw material of component A to the raw material of component B is 1:0.2. The raw material of component A is high-density polyethylene, and the raw material of component B is maleic anhydride grafted modified polyethylene; The raw material of the filler is composed of coconut shell, diatomite, additive and bamboo fiber powder, and the mass ratio of each raw material is 1:(1.3):(0.7):(0.3); The raw material of the auxiliary agent is composed of polyethylene terephthalate, polycarbonate, polybutylene terephthalate and talcum powder, and the mass ratio of each raw material is 1:(0.25):(0.15):(0.025).

[0033] The pretreatment method of coconut shell is as follows: the coconut shell is crushed, and the crushing particle size is 6 mm. Then it is sent into an oven, and the oven is set at 110 °C for drying treatment for 45 min. After the drying treatment is completed, it is sent into a carbonization furnace for carbonization treatment. The carbonization furnace is set with a heating rate of 15 °C / min and heated to 600 °C. The obtained product is added into a reaction kettle, and potassium hydroxide solution is added into the reaction kettle. The reaction kettle is set to be heated to 110 °C, and the stirring speed is 140 r / min. It is kept warm and stirred for 2 h, and nitrogen is introduced during the treatment process. The obtained product is washed with deionized water, and then sent into an oven. The oven is set at 90 °C for drying treatment. The obtained product is ground, and the grinding particle size is 20 μm, thus completing the pretreatment of the coconut shell.

[0034] The mass concentration of the potassium hydroxide solution is 40%, and the mass of the potassium hydroxide solution is 25% of the mass of the coconut shell.

[0035] The additive is prepared by the following method: thioacetamide and sodium molybdate are added into deionized water, and the mixture is heated in a water bath to 85 °C and kept warm and stirred for 25 min. After the treatment is completed, absolute ethanol and carbon nitride nanosheets are added, and the temperature is raised to 95 °C and kept warm and stirred for 13 min. After the treatment is completed, concentrated hydrochloric acid is added, and it is set to be kept warm and react at 85 °C for 13 min. The obtained product is washed with deionized water until the pH value is 6.5, and then sent into an oven. It is set at 180 °C for drying treatment for 3 h, and then the temperature is raised to 350 °C and kept warm in a nitrogen atmosphere for 50 min. The obtained product is ground, and the grinding particle size is 20 μm, thus preparing the additive.

[0036] The mass ratio of thioacetamide, sodium molybdate and deionized water is 1:(0.5):(25). The mass of absolute ethanol is 7 times the mass of thioacetamide. The mass of carbon nitride nanosheets is 15% of the mass of thioacetamide. The mass of concentrated hydrochloric acid is 70% of the mass of thioacetamide.

[0037] The filler is prepared by the following method: the additive and deionized water are added into a mixer. The mass of deionized water is 75% of the mass of the additive. The mixer is set to stir at 250 r / min for 8 min, and then diatomite and bamboo fiber powder are added in sequence. The mixer is set to stir at 350 r / min for 25 min. The obtained product is left to age for 3 d, and then sent into a centrifuge. The centrifuge is set to centrifuge at 3000 r / min for 8 min, and the supernatant is discarded. The obtained precipitate is washed with deionized water, and the obtained product is sent into an oven. It is set at 110 °C for drying treatment for 14 min, thus preparing the filler.

[0038] The auxiliary agent is prepared by the following method: Polyethylene terephthalate and polycarbonate are added into a mixer, and the raw material of component B and polybutylene terephthalate are added into the mixer. The mixer is set to stir at 250 r / min for 15 min, then talcum powder is added, and the mixer is set to stir at 350 r / min for 150 min to obtain the auxiliary agent.

[0039] The silicon dioxide is selected as nano-silicon dioxide particles with a particle size of 30 nm.

[0040] The stabilizer is selected as dioctyl phthalate, and the antioxidant is selected as antioxidant 168.

[0041] S1: Weigh the raw material of component A, filler, auxiliary agent, silicon dioxide, stabilizer and antioxidant as required and add them into a mixer. The mixer is set to stir at 700 r / min for 25 min to obtain the first mixture. S2: The first mixture is added into a mixer. The mixer is set to mix at 230 °C for 1.5 h to obtain the second mixture. S3: The second mixture is added into a twin-screw extruder, and is extruded and formed at a set temperature of 210 °C to obtain a PE long tube. After cooling, sizing and cutting, the PE pipe is obtained.

[0042] Example 3:

[0043] It includes the following raw materials in parts by weight: 60 parts of polyethylene, 8 parts of filler, 6 parts of auxiliary agent, 6 parts of silicon dioxide, 4 parts of stabilizer, and 4 parts of antioxidant. The polyethylene is divided into the raw material of component A and the raw material of component B. Among them, the mass ratio of the raw material of component A to the raw material of component B is 1:0.2. The raw material of component A is selected as high-density polyethylene, and the raw material of component B is selected as maleic anhydride grafted modified polyethylene. The raw material of the filler is composed of coconut shell, diatomite, additive and bamboo fiber powder, and the mass ratio of each raw material is 1:(1.4):(0.8):(0.4). The raw material of the auxiliary agent is composed of polyethylene terephthalate, polycarbonate, polybutylene terephthalate and talcum powder, and the mass ratio of each raw material is 1:(0.3):(0.2):(0.03).

[0044] The pretreatment method of coconut shell is as follows: The coconut shell is crushed to a particle size of 10 mm, and then sent into an oven. The oven is set at 120 °C for drying treatment for 50 min. After the drying treatment is completed, it is sent into a carbonization furnace for carbonization treatment. The carbonization furnace is set at a heating rate of 20 °C / min and heated to 650 °C. The obtained product is added into a reaction kettle, and potassium hydroxide solution is added into the reaction kettle. The reaction kettle is set to be heated to 120 °C, and the stirring speed is 160 r / min. It is kept warm and stirred for 3 h, and nitrogen is introduced during the treatment process. The obtained product is washed with deionized water, and then sent into an oven. The oven is set at 100 °C for drying treatment. The obtained product is ground to a particle size of 30 μm, and the pretreatment of the coconut shell is completed.

[0045] The mass concentration of the potassium hydroxide solution is 50%, and the mass of the potassium hydroxide solution is 30% of the mass of the coconut shell.

[0046] The additive is prepared by the following method: Thioacetamide and sodium molybdate are added into deionized water, and the mixture is heated in a water bath to 90 °C and kept warm and stirred for 30 min. After the treatment is completed, absolute ethanol and carbon nitride nanosheets are added, and the temperature is raised to 100 °C and kept warm and stirred for 16 min. After the treatment is completed, concentrated hydrochloric acid is added, and the temperature is set at 90 °C for heat preservation reaction for 16 min. The obtained product is washed with deionized water until the pH value is 7, and then sent into an oven. The oven is set at 200 °C for drying treatment for 4 h, and then the temperature is set to be raised to 400 °C and kept warm in a nitrogen atmosphere for 60 min. The obtained product is ground to a particle size of 30 μm to prepare the additive.

[0047] The mass ratio of thioacetamide, sodium molybdate and deionized water is 1:(0.6):(30), the mass of absolute ethanol is 8 times the mass of thioacetamide, the mass of carbon nitride nanosheets is 20% of the mass of thioacetamide, and the mass of concentrated hydrochloric acid is 80% of the mass of thioacetamide.

[0048] The filler is prepared by the following method: The additive and deionized water are added into a mixer. The mass of deionized water is 80% of the mass of the additive. The mixer is set to stir at 300 r / min for 10 min, and then diatomite and bamboo fiber powder are added in sequence. The mixer is set to stir at 400 r / min for 30 min. The obtained product is left to stand and age for 4 d, and then sent into a centrifuge. The centrifuge is set to centrifuge at 4000 r / min for 10 min, and the supernatant is discarded. The obtained precipitate is washed with deionized water, and the obtained product is sent into an oven. The oven is set at 120 °C for drying treatment for 16 min to prepare the filler.

[0049] The auxiliary agent is prepared by the following method: Polyethylene terephthalate and polycarbonate are added into a mixing machine, and component B raw materials and polybutylene terephthalate are added into the mixing machine. The mixing machine is set to stir at 300 r / min for 20 min, then talcum powder is added, and the mixing machine is set to stir at 400 r / min for 20 min to obtain the auxiliary agent.

[0050] The silica is selected as nano-silica particles with a particle size of 50 nm.

[0051] The stabilizer is selected as diisooctyl phthalate, and the antioxidant is selected as antioxidant 3114.

[0052] S1: Weigh the component A raw materials, filler, auxiliary agent, silica, stabilizer and antioxidant as required and add them into a mixing machine. The mixing machine is set to stir at 800 r / min for 30 min to obtain the first mixture. S2: The first mixture is added into a kneading machine, and the kneading machine is set to knead at 240 °C for 2 h to obtain the second mixture. S3: The second mixture is added into a twin-screw extruder, and the temperature is set to 220 °C for extrusion molding to obtain a PE long tube. After cooling, sizing and cutting, the PE pipe is prepared.

[0053] Comparative example 1: The difference between this comparative example and Example 1 is that: in this comparative example, an equal amount of coconut shell powder is selected to replace the filler.

[0054] Comparative example 2: The difference between this comparative example and Example 1 is that: in this comparative example, no silica is contained.

[0055] Comparative example 3: The difference between this comparative example and Example 1 is that: in this comparative example, no filler is contained. Comparative example 4: The difference between this comparative example and Example 1 is that: in this comparative example, no auxiliary agent is contained.

[0056] Performance test: The PE pipes prepared in Example 1, Example 2, Example 3, Comparative example 1, Comparative example 2, Comparative example 3 and Comparative example 4 are subjected to performance tests, and the obtained test data are recorded in the following table:

[0057] In the performance test, the tensile strength of the PE pipes prepared in Example 1, Example 2, Example 3, Comparative example 1, Comparative example 2, Comparative example 3 and Comparative example 4 is tested according to the test standard in ISO527-1; The flexural strength of the PE pipes prepared in Example 1, Example 2, Example 3, Comparative example 1, Comparative example 2, Comparative example 3 and Comparative example 4 is tested according to the test standard in ASTM D790; The impact strength test was carried out on the PE pipes prepared in Example 1, Example 2, Example 3, Comparative Example 1, Comparative Example 2, Comparative Example 3 and Comparative Example 4 according to the test standard in ASTM D256.

[0058] It can be seen that the tensile strength, flexural strength and impact strength properties of the PE pipes prepared in Comparative Examples 1, 2, 3 and 4 are all lower than those in Examples 1, 2 and 3. This shows that: by adding fillers during the preparation of PE pipes, among which, after the coconut shell is carbonized and ground, a porous carbon structure is formed, which can effectively enhance the interfacial bonding force between materials, make it evenly dispersed in the PE matrix, bear part of the external force and play a role in structural enhancement. By adding additives in the filler, the molybdate ions generated by thioacetamide and sodium molybdate can be evenly precipitated and grown on the surface and pores of the coconut shell powder, form a relatively tight bond with the coconut shell powder, and effectively improve the structural stability of the PE pipe; By adding additives during the preparation of PE pipes, among which, by using the high modulus characteristics of polyethylene terephthalate and the creep resistance and high toughness characteristics of polycarbonate, polyethylene terephthalate provides a high-strength skeleton, complements the rigidity and toughness with polycarbonate, and forms a stable complementary structure. The anhydride group of maleic anhydride forms an ester exchange reaction with the ester group of polyethylene terephthalate, reduces the interfacial tension, and further improves the overall strength performance of the PE pipe.

[0059] By comparing and analyzing the relevant data in the table, it can be seen that the PE pipes prepared by the present invention not only have good tensile strength and flexural strength properties, but also have excellent impact strength properties. This shows that the PE pipes and their preparation methods provided by the present invention have a broader market prospect and are more suitable for popularization.

[0060] In the description of this specification, the description with reference to terms such as "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0061] 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 limit the invention to the specific embodiments described. Obviously, many modifications and variations 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 in the technical field can well understand and utilize the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A PE pipe, characterized in that: It includes the following raw materials in parts by weight: 40 - 60 parts of polyethylene, 6 - 8 parts of filler, 4 - 6 parts of auxiliary agent, 4 - 6 parts of silicon dioxide, 2 - 4 parts of stabilizer, and 2 - 4 parts of antioxidant; The polyethylene is divided into component A raw material and component B raw material. Among them, the mass ratio of component A raw material to component B raw material is 1:0.

2. Component A raw material selects high - density polyethylene, and component B raw material selects maleic anhydride - grafted modified polyethylene; The raw material of the filler consists of coconut shell, diatomite, additive, and bamboo fiber powder, and the mass ratio of each raw material is 1:(1.2 - 1.4):(0.6 - 0.8):(0.2 - 0.4); The raw material of the auxiliary agent consists of polyethylene terephthalate, polycarbonate, polybutylene terephthalate, and talc powder, and the mass ratio of each raw material is 1:(0.2 - 0.3):(0.1 - 0.2):(0.02 - 0.03).

2. The PE pipe according to claim 1, wherein The pretreatment method of the coconut shell is as follows: The coconut shell is crushed, and the crushing particle size is 2 - 10 mm. Then it is sent into an oven, and the oven is set at 100 - 120 °C for drying treatment for 40 - 50 min. After the drying treatment is completed, it is sent into a carbonization furnace for carbonization treatment. The carbonization furnace is set with a heating rate of 10 - 20 °C / min and heated to 550 - 650 °C. The obtained product is added into a reaction kettle, and potassium hydroxide solution is added into the reaction kettle. The reaction kettle is set to be heated to 100 - 120 °C, the stirring speed is 120 - 160 r / min, and it is kept stirring for 1 - 3 h. Nitrogen is introduced during the treatment process. The obtained product is rinsed with deionized water, then sent into an oven, and the oven is set at 80 - 100 °C for drying treatment. The obtained product is ground, and the grinding particle size is 10 - 30 μm, thus completing the pretreatment of the coconut shell.

3. The PE pipe according to claim 2, wherein The mass concentration of the potassium hydroxide solution is 30 - 50%, and the mass of the potassium hydroxide solution is 20 - 30% of the mass of the coconut shell.

4. The PE pipe according to claim 1, characterized in that, The additive is prepared by the following method: Thioacetamide and sodium molybdate are added into deionized water, and it is heated in a water bath to 80 - 90 °C and kept stirring for 20 - 30 min. After the treatment is completed, absolute ethanol and carbon nitride nanosheets are added, and the temperature is raised to 90 - 100 °C and kept stirring for 10 - 16 min. After the treatment is completed, concentrated hydrochloric acid is added, and it is set to be kept reacting at 80 - 90 °C for 10 - 16 min. The obtained product is washed with deionized water until the pH value is 6 - 7, then sent into an oven, set at 160 - 200 °C for drying treatment for 2 - 4 h, and then set to be heated to 300 - 400 °C and kept in a nitrogen atmosphere for 40 - 60 min. The obtained product is ground, and the grinding particle size is 10 - 30 μm, thus preparing the additive.

5. The PE pipe according to claim 1, wherein The mass ratio of thioacetamide, sodium molybdate, and deionized water is 1:(0.4 - 0.6):(20 - 30). The mass of absolute ethanol is 6 - 8 times the mass of thioacetamide. The mass of carbon nitride nanosheets is 10 - 20% of the mass of thioacetamide. The mass of concentrated hydrochloric acid is 60 - 80% of the mass of thioacetamide.

6. The PE pipe according to claim 1, wherein The filler is prepared by the following method: The additive and deionized water are added into a mixer. The mass of the deionized water is 70-80% of the mass of the additive. The mixer is set to stir at 200-300 r / min for 6-10 min. Then, diatomite and bamboo fiber powder are added in sequence. The mixer is set to stir at 300-400 r / min for 20-30 min. The obtained product is left to stand and age for 2-4 d. Then, it is sent into a centrifuge. The centrifuge is set to centrifuge at 2000-4000 r / min for 6-10 min. The supernatant is discarded. The obtained precipitate is washed with deionized water. The obtained product is sent into an oven and dried at 100-120 °C for 12-16 min to obtain the filler.

7. The PE pipe according to claim 6, characterized in that, The auxiliary agent is prepared by the following method: Polyethylene terephthalate and polycarbonate are added into a mixer. Component B raw material and polybutylene terephthalate are added into the mixer. The mixer is set to stir at 200-300 r / min for 10-20 min. Then, talcum powder is added. The mixer is set to stir at 300-400 r / min for 10-20 min to obtain the auxiliary agent.

8. The PE pipe according to claim 1, characterized in that, The silicon dioxide selected is nano-silicon dioxide particles with a particle size of 10-50 nm.

9. The PE pipe according to claim 1, characterized in that, The stabilizer is selected from any one of diisooctyl phthalate and dioctyl phthalate, and the antioxidant is selected from any one of antioxidant 1076, antioxidant 168, and antioxidant 3114.

10. The preparation method of the PE pipe according to any one of claims 1 to 9, characterized in that, It includes the following steps: S1: Weigh the component A raw material, filler, auxiliary agent, silicon dioxide, stabilizer, and antioxidant as required and add them into a mixer. The mixer is set to stir at 600-800 r / min for 20-30 min to obtain the first mixed material. S2: The first mixed material is added into a mixer. The mixer is set to mix at 220-240 °C for 1-2 h to obtain the second mixed material. S3: The second mixed material is added into a twin-screw extruder and extruded and formed at a temperature of 200-220 °C to obtain a PE long tube. After cooling, sizing, and cutting, the PE pipe is obtained.

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