PVC threading tube and preparation method thereof
By adding functionalized grafted elastomers and functional fillers to PVC resin to form a three-dimensional network structure, the problems of high brittleness and poor toughness of PVC at low temperatures are solved, achieving a balance of high toughness, thermal stability and rigidity, which is suitable for industrial production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- FOSHAN RIFENG NEW PIPE
- Filing Date
- 2026-04-03
- Publication Date
- 2026-06-30
AI Technical Summary
Existing PVC resins are brittle and have poor toughness at low temperatures, and existing modification methods suffer from weak interfacial bonding, poor compatibility, and high costs, making them difficult to apply in cold environments.
Functionalized grafted elastomers are modified by melt grafting, grafting a first monomer, a second monomer, and a third monomer onto the elastomer, and combining them with functional fillers to form a three-dimensional network structure, thereby improving the toughness and rigidity of PVC.
It significantly improves the low-temperature toughness and thermal stability of PVC, forms strong interfacial interactions, achieves a balance between rigidity and toughness, and is suitable for large-scale production.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of polymer materials technology, and more specifically, to a PVC conduit and its preparation method. Background Technology
[0002] Polyvinyl chloride (PVC) is widely used in building drainage pipes, electrical insulation, flame retardancy, and cost-effectiveness. Rigid PVC-U pipes, in particular, have become the market mainstream due to their high rigidity and long service life. However, PVC resin itself is a brittle material with low notched impact strength, especially poor low-temperature toughness. In cold environments, PVC-U pipes are highly susceptible to cracking due to external impacts, foundation settlement, or low-temperature embrittlement, leading to the phenomenon of "low-temperature brittleness," which severely limits its widespread application in cold northern regions or freezing environments.
[0003] To address the aforementioned issues, existing technologies typically employ the addition of toughening modifiers to improve the toughness of PVC. Common modification methods include physical blending modification by directly adding elastomers such as chlorinated polyethylene (CPE), acrylate copolymers (ACR), and methyl methacrylate-butadiene-styrene copolymers (MBS). However, simple physical blending often suffers from weak interfacial bonding and poor compatibility, resulting in inadequate toughening effects, often at the expense of material rigidity, heat resistance, or weather resistance. For example, while the addition of CPE can improve toughness, it reduces the Vicat softening temperature and rigidity of the pipe; and while ordinary rubber-based elastomers offer good low-temperature toughness, they have poor weather resistance and are prone to aging. Furthermore, although there are reports of grafting modification methods in existing technologies, most focus on grafting single monomers or complex synthesis processes targeting specific elastomers, which are cumbersome, costly, and unsuitable for industrial production.
[0004] Therefore, how to develop a PVC conduit that combines excellent low-temperature toughness, good weather resistance, high rigidity, and excellent processing performance, while simplifying the manufacturing process, remains a technical challenge that urgently needs to be solved in this field. Summary of the Invention
[0005] In view of this, in order to solve one of the above-mentioned technical problems, the present invention provides a PVC conduit and its preparation method, the specific technical solution of which is as follows:
[0006] A PVC conduit, the PVC conduit comprising the following raw materials in parts by weight: 100 parts PVC resin, 8-20 parts functionalized grafted elastomer, 5-15 parts functional filler, 2-5 parts heat stabilizer, 0.5-2 parts lubricant, and 0.3-1 parts antioxidant; The functionalized grafted elastomer is obtained by melt grafting modification, in which a first monomer, a second monomer, and a third monomer are simultaneously grafted onto the elastomer.
[0007] Furthermore, the elastomer is at least one of ethylene-vinyl acetate copolymer, ethylene-octene copolymer, ethylene propylene diene monomer (EPDM) rubber, acrylate rubber, and nitrile rubber.
[0008] Furthermore, the first monomer is at least one of maleic anhydride and acrylic acid; the second monomer is at least one of styrene and methyl methacrylate.
[0009] Furthermore, the third monomer is N-cyclohexylmaleimide.
[0010] Furthermore, the preparation method of the functionalized grafted elastomer is as follows: the elastomer, the first monomer, the second monomer, the third monomer, the initiator and the processing aid are mixed evenly, and then a melt grafting reaction is carried out through an extruder to obtain the functionalized grafted elastomer.
[0011] Further, the weight ratio of the elastomer, the first monomer, the second monomer, the third monomer, the initiator and the processing aid is (80~100):(3~5):(1~5):(1~3):(0.1~0.5):(0.5~1).
[0012] Furthermore, the mixture is stirred at a speed of 800 r / min to 1500 r / min for 5 min to 10 min, and then melt-grafted at 150℃ to 200℃ for 5 min to 10 min, with the screw speed being 100 rpm to 400 rpm.
[0013] Furthermore, the initiator is at least one of dicumyl peroxide and benzoyl peroxide.
[0014] Furthermore, the functional filler is obtained by mixing silicon carbide and hydroxyapatite in a mass ratio of (1~5):(3~9) and then modifying them.
[0015] In addition, the present invention also provides a method for preparing PVC conduit, the method comprising the following steps: S1. Add PVC resin, functionalized grafted elastomer, functional filler, heat stabilizer, lubricant and antioxidant to a high-speed mixer and mix evenly to obtain a mixture. S2. The mixture is added to an extruder and melted and plasticized, then extruded through a die, and after vacuum shaping, cooling and cutting, PVC conduit is obtained.
[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention, by incorporating a functionalized grafted elastomer, significantly improves toughness while the interaction between the first and second monomers imparts a degree of rigidity to the elastomer. Furthermore, the introduction of an N-cyclohexylmaleimide as a third monomer results in a branched structure in the multi-monomer melt-grafted modified functionalized grafted elastomer, leading to stronger interfacial interactions between the elastomer and the PVC matrix. At low temperatures, the functionalized elastomer effectively induces numerous crazes and shear bands in the matrix, absorbing impact energy and significantly improving the brittle fracture problem of PVC-U pipes under low-temperature conditions.
[0017] 2. The N-cyclohexylmaleimide introduced in this invention contains a rigid imide cyclic structure, which can significantly improve the thermal stability of elastomers and PVC conduits, and help improve the material's resistance to heat and oxygen aging. Furthermore, when combined with needle-like nano-hydroxyapatite and silicon carbide used in the functional fillers, a stable three-dimensional network structure is formed in the system, further hindering the intrusion of oxygen and heat, thereby delaying the aging of the material.
[0018] 3. The functional filler of this invention undergoes modification treatment to reduce its surface energy, significantly improving its compatibility with PVC resin and elastomer, and effectively preventing secondary agglomeration of nanoparticles during processing. Simultaneously, the monomers grafted onto the elastomer work together to achieve uniform microscale dispersion of the elastomer within the PVC matrix. This excellent dispersibility endows the composite system with superior processing fluidity, moderate melt strength during extrusion molding, smooth inner and outer walls of the pipe, low extrusion torque, and reduced energy consumption, making it suitable for large-scale continuous production.
[0019] 4. The functional filler of this invention is composed of nano-silicon carbide (high hardness, high thermal conductivity) and needle-like nano-hydroxyapatite (high aspect ratio, reinforcement). It not only plays a filling role, but also significantly strengthens the PVC matrix due to the overlapping effect of needle-like hydroxyapatite and the rigidity point effect of silicon carbide. This improves the overall performance of PVC conduit, achieves a balance between rigidity and toughness, and has higher application value. Detailed Implementation
[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to its embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the scope of protection of the invention.
[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.
[0022] According to one embodiment of the present invention, a PVC conduit is provided, wherein the PVC conduit comprises the following raw materials in parts by weight: 100 parts PVC resin, 8-20 parts functionalized grafted elastomer, 5-15 parts functional filler, 2-5 parts heat stabilizer, 0.5-2 parts lubricant, and 0.3-1 parts antioxidant; The functionalized grafted elastomer is obtained by melt grafting modification, in which a first monomer, a second monomer, and a third monomer are simultaneously grafted onto the elastomer.
[0023] In one embodiment, the elastomer is at least one of ethylene-vinyl acetate copolymer, ethylene-octene copolymer, ethylene propylene diene monomer (EPDM) rubber, acrylate rubber, and nitrile rubber.
[0024] In one embodiment, the first monomer is at least one of maleic anhydride and acrylic acid; the second monomer is at least one of styrene and methyl methacrylate.
[0025] In one embodiment, the third monomer is N-cyclohexylmaleimide.
[0026] In one embodiment, the preparation method of the functionalized grafted elastomer is as follows: the elastomer, the first monomer, the second monomer, the third monomer, the initiator and the processing aid are mixed evenly, and then a melt grafting reaction is carried out through an extruder to obtain the functionalized grafted elastomer.
[0027] In one embodiment, the weight ratio of the elastomer, the first monomer, the second monomer, the third monomer, the initiator and the processing aid is (80~100):(3~5):(1~5):(1~3):(0.1~0.5):(0.5~1).
[0028] In one embodiment, the mixture is stirred at a speed of 800 r / min to 1500 r / min for 5 min to 10 min, and then melt-grafted at 150°C to 200°C for 5 min to 10 min, with the screw speed being 100 rpm to 400 rpm.
[0029] In one embodiment, the initiator is at least one of dicumyl peroxide and benzoyl peroxide.
[0030] In one embodiment, the processing aid is at least one of paraffin wax and silicone oil.
[0031] In one embodiment, the functional filler is obtained by mixing silicon carbide and hydroxyapatite in a mass ratio of (1~5):(3~9) and then modifying them.
[0032] In one embodiment, the silicon carbide has a particle size of 30 nm to 50 nm.
[0033] In one embodiment, the hydroxyapatite is needle-shaped nano-hydroxyapatite with an average length of 50-100 nm and an aspect ratio >10.
[0034] In one embodiment, the modification process is as follows: silicon carbide and hydroxyapatite are mixed and added to a modifying agent, stirred at a speed of 50 r / min to 100 r / min and at 65°C to 80°C for 30 min to 60 min, and then centrifuged, washed and dried to obtain the functional filler.
[0035] In one embodiment, the modified treatment agent is obtained by mixing a silane coupling agent, ethanol and water in a volume ratio of (1~5):(1~4):(1~3).
[0036] In one embodiment, the silane coupling agent is at least one of γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and γ-aminopropyltrimethoxysilane.
[0037] In one embodiment, the heat stabilizer is a thiol methyltin stabilizer.
[0038] In one embodiment, the lubricant is at least one of calcium stearate, oxidized polyethylene wax, and hard fatty acids.
[0039] In one embodiment, the antioxidant is at least one of ditetradecanoic acid ester and dioctadecanoic acid ester.
[0040] In addition, the present invention also provides a method for preparing PVC conduit, the method comprising the following steps: S1. Add PVC resin, functionalized grafted elastomer, functional filler, heat stabilizer, lubricant and antioxidant to a high-speed mixer and mix evenly to obtain a mixture. S2. The mixture is added to an extruder and melted and plasticized, then extruded through a die, and after vacuum shaping, cooling and cutting, PVC conduit is obtained.
[0041] In one embodiment, in step S1, the mixture is processed at a rotation speed of 1000 r / min to 1500 r / min for 5 min to 15 min.
[0042] In one embodiment, in step S2, the processing temperature is 160°C to 190°C.
[0043] The above solution optimizes the raw materials used in the preparation of PVC conduit, resulting in a material with excellent impact resistance and cold resistance, thus meeting market demands.
[0044] The embodiments of the present invention will be described in detail below with reference to specific examples. Materials not mentioned in the following embodiments are all commercially available, and processes not specifically defined are considered conventional techniques and will not be elaborated upon here.
[0045] Example 1: A method for preparing PVC conduit includes the following steps: S1. By weight, add 100 parts of PVC resin, 12 parts of functionalized grafted elastomer, 14 parts of functional filler, 3 parts of methyl tin mercaptan stabilizer, 1 part of calcium stearate and 1 part of ditetradecyl alcohol ester to a high-speed mixer and mix at 1000 r / min for 10 min to obtain a mixture. The preparation method of the functionalized grafted elastomer is as follows: 80 parts by weight of EPDM rubber, 4 parts by weight of maleic anhydride, 3 parts by weight of methyl methacrylate, 3 parts by weight of N-cyclohexylmaleimide, 0.3 parts by weight of dicumyl peroxide and 0.5 parts by weight of silicone oil are mixed at a speed of 800 r / min for 10 min, and then melt-grafted at 180°C for 10 min with a screw speed of 100 rpm to obtain the functionalized grafted elastomer. The functional filler is prepared by mixing silicon carbide and hydroxyapatite in a mass ratio of 4:6, adding a modifying agent (obtained by mixing γ-aminopropyltrimethoxysilane, ethanol, and water in a volume ratio of 4:4:2), stirring at 50 r / min and 70℃ for 45 min, and then centrifuging, washing, and drying to obtain the functional filler. The silicon carbide has a particle size of 50 nm; the hydroxyapatite is needle-shaped nano-hydroxyapatite with an average length of 100 nm and an aspect ratio of 15. S2. The mixture is added to an extruder and melted and plasticized, then extruded through a die at a processing temperature of 160℃~190℃. After vacuum shaping, cooling, and cutting, PVC conduit is obtained.
[0046] Example 2: A method for preparing PVC conduit includes the following steps: S1. By weight, add 100 parts of PVC resin, 15 parts of functionalized grafted elastomer, 15 parts of functional filler, 4 parts of methyl tin mercaptan stabilizer, 1 part of calcium stearate and 0.8 parts of ditetradecyl alcohol ester to a high-speed mixer and mix at 1000 r / min for 10 min to obtain a mixture. The preparation method of the functionalized grafted elastomer is as follows: 80 parts by weight of ethylene-octene copolymer, 5 parts by weight of maleic anhydride, 3 parts by weight of methyl methacrylate, 2 parts by weight of N-cyclohexylmaleimide, 0.2 parts by weight of dicumyl peroxide and 0.5 parts by weight of silicone oil are mixed at a speed of 1000 r / min for 10 min, and then melt-grafted at 180°C for 10 min with a screw speed of 100 rpm to obtain the functionalized grafted elastomer. The functional filler is prepared by mixing silicon carbide and hydroxyapatite in a mass ratio of 3:7, adding a modifying agent (obtained by mixing γ-aminopropyltrimethoxysilane, ethanol, and water in a volume ratio of 4:4:2), stirring at 50 r / min and 75 °C for 40 min, and then centrifuging, washing, and drying to obtain the functional filler. The silicon carbide has a particle size of 50 nm; the hydroxyapatite is needle-shaped nano-hydroxyapatite with an average length of 100 nm and an aspect ratio of 15. S2. The mixture is added to an extruder and melted and plasticized, then extruded through a die at a processing temperature of 160℃~190℃. After vacuum shaping, cooling, and cutting, PVC conduit is obtained.
[0047] Example 3: A method for preparing PVC conduit includes the following steps: S1. By weight, add 100 parts of PVC resin, 17 parts of functionalized grafted elastomer, 15 parts of functional filler, 5 parts of methyl tin mercaptan stabilizer, 2 parts of calcium stearate and 1 part of ditetradecyl alcohol ester to a high-speed mixer and mix at 1000 r / min for 15 min to obtain a mixture. The preparation method of the functionalized grafted elastomer is as follows: 100 parts by weight of acrylate rubber, 3 parts by weight of maleic anhydride, 4 parts by weight of methyl methacrylate, 3 parts by weight of N-cyclohexylmaleimide, 0.3 parts by weight of dicumyl peroxide and 0.6 parts by weight of silicone oil are mixed at a speed of 1000 r / min for 10 min, and then melt-grafted at 185°C for 10 min with a screw speed of 100 rpm to obtain the functionalized grafted elastomer. The functional filler is prepared by mixing silicon carbide and hydroxyapatite in a mass ratio of 5:5, adding a modifying agent (obtained by mixing γ-aminopropyltrimethoxysilane, ethanol, and water in a volume ratio of 4:4:2), stirring at 50 r / min and 75 °C for 40 min, and then centrifuging, washing, and drying to obtain the functional filler. The silicon carbide has a particle size of 50 nm; the hydroxyapatite is needle-shaped nano-hydroxyapatite with an average length of 100 nm and an aspect ratio of 15. S2. The mixture is added to an extruder and melted and plasticized, then extruded through a die at a processing temperature of 160℃~190℃. After vacuum shaping, cooling, and cutting, PVC conduit is obtained.
[0048] Comparative Example 1: The difference between Comparative Example 1 and Example 3 is that the preparation method of the functionalized grafted elastomer in Comparative Example 1 is different, while the rest is the same as in Example 3. The preparation method of the functionalized grafted elastomer in Comparative Example 1 is as follows: 100 parts by weight of elastomer, 10 parts by weight of maleic anhydride, 0.3 parts by weight of dicumyl peroxide and 0.6 parts by weight of silicone oil are mixed at a speed of 1000 r / min for 10 min, and then melt-grafted at 185℃ for 10 min with the screw speed at 100 rpm to obtain the functionalized grafted elastomer.
[0049] Comparative Example 2: The difference between Comparative Example 2 and Example 3 is that the preparation method of the functionalized grafted elastomer in Comparative Example 2 is different, while the rest is the same as in Example 3; The preparation method of the functionalized grafted elastomer in Comparative Example 2 is as follows: 100 parts by weight of elastomer, 10 parts by weight of methyl methacrylate, 0.3 parts by weight of dicumyl peroxide and 0.6 parts by weight of silicone oil are mixed at a speed of 1000 r / min for 10 min, and then melt-grafted at 185℃ for 10 min with the screw speed at 100 rpm to obtain the functionalized grafted elastomer.
[0050] Comparative Example 3: The difference between Comparative Example 3 and Example 3 is that the preparation method of the functionalized grafted elastomer in Comparative Example 3 is different, while the rest is the same as in Example 3. The preparation method of the functionalized grafted elastomer in Comparative Example 3 is as follows: 100 parts by weight of elastomer, 10 parts by weight of N-cyclohexylmaleimide, 0.3 parts by weight of dicumyl peroxide and 0.6 parts by weight of silicone oil are mixed at a speed of 1000 r / min for 10 min, and then melt-grafted at 185℃ for 10 min with the screw speed at 100 rpm to obtain the functionalized grafted elastomer.
[0051] Comparative Example 4: The difference between Comparative Example 4 and Example 3 is that Comparative Example 4 directly uses acrylate rubber (replacing the functionalized grafted elastomer), while the rest is the same as Example 3.
[0052] Comparative Example 5: The difference between Comparative Example 5 and Example 3 is that no functionalized grafted elastomer was added in Comparative Example 5, but otherwise it is the same as Example 3.
[0053] Comparative Example 6: The difference between Comparative Example 6 and Example 3 is that the functional filler in Comparative Example 6 is a single silicon carbide, while the rest is the same as in Example 3.
[0054] Comparative Example 7: The difference between Comparative Example 7 and Example 3 is that the functional filler in Comparative Example 7 is a single hydroxyapatite, while the rest is the same as in Example 3.
[0055] Comparative Example 8: The difference between Comparative Example 8 and Example 3 is that calcium carbonate is used as the filler in Comparative Example 8 (replacing the functional filler), while the rest is the same as in Example 3.
[0056] The PVC conduit samples prepared in Examples 1-3 and the PVC conduit samples prepared in Comparative Examples 1-9 were subjected to performance tests, and the results are shown in Table 1 below.
[0057] Among them: impact performance and Vicat softening temperature tests refer to GB / T5836.1-2018, tensile strength tests refer to GB / T8804.2-2003, and aging resistance tests refer to GB / T16422.2-2022.
[0058] Table 1: Performance Test Results
[0059] Analysis of the data in the table shows that this invention, by adding functionalized grafted elastomers and grafting the first, second, and third monomers, significantly increases the bonding between the elastomer and PVC interface, resulting in better low-temperature toughening. The overall product exhibits excellent low-temperature toughness, rigidity retention, heat resistance, and aging resistance. Compared to Example 3, the functionalized grafted elastomer in Comparative Example 1 is only grafted with maleic anhydride. Although this introduces a polar group and improves the interfacial compatibility with PVC, the effect is not as good as in Example 3. Furthermore, the single maleic anhydride graft is prone to homopolymerization, resulting in a simple graft chain structure and overall performance inferior to Example 3. In Comparative Example 2, the functionalized grafted elastomer is only grafted with methyl methacrylate, which imparts a certain degree of polarity to the functionalized grafted elastomer. The compatibility between the MMA grafted segments and PVC is mainly achieved through dipole-dipole interactions. The functionalized grafted elastomer in Comparative Example 3 lacks chemical bonding, resulting in weak interfacial adhesion and low impact energy transfer efficiency, making its overall performance inferior to Example 3. In Comparative Example 4, the functionalized grafted elastomer only grafted with N-cyclohexylmaleimide, exhibiting poor interfacial compatibility with PVC and lacking the polar groups of MAH, thus failing to form strong interfacial bonds and effectively transferring impact energy, resulting in inferior overall performance compared to Example 3. In Comparative Example 4, acrylate rubber was not directly used (to replace the functionalized grafted elastomer), leading to poor interfacial adhesion with PVC and uneven dispersion of the elastomer in the matrix. The performance of Comparative Example 5 was significantly worse than that of Example 3 due to the lack of uniformity of the grafted elastomer. In Comparative Example 6, no functionalized grafted elastomer was added, resulting in a lack of toughening effect. At low temperatures, molecular chain movement was restricted, increasing brittleness, and the molecular chains broke after aging, leading to a significant decrease in impact strength. In Comparative Example 7, the functional filler was a single silicon carbide particle. While silicon carbide is a rigid particle that can improve hardness and thermal conductivity, it lacks the effect of needle-like hydroxyapatite, failing to form a superior three-dimensional network structure. Furthermore, the lack of the overlapping effect of hydroxyapatite limited its ability to disperse impact energy, resulting in overall performance inferior to Example 3. In Comparative Example 8, conventional calcium carbonate was used as the filler (replacing the functional filler). Conventional calcium carbonate is micron- or submicron-sized, with large particle size and small specific surface area. It was not modified, resulting in poor compatibility and a tendency to cause stress concentration, leading to overall performance inferior to Example 3.
[0060] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0061] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.
Claims
1. A PVC conduit, characterized in that, The PVC conduit comprises the following raw materials in parts by weight: 100 parts PVC resin, 8-20 parts functionalized grafted elastomer, 5-15 parts functional filler, 2-5 parts heat stabilizer, 0.5-2 parts lubricant, and 0.3-1 parts antioxidant; The functionalized grafted elastomer is obtained by melt grafting modification, in which a first monomer, a second monomer, and a third monomer are simultaneously grafted onto the elastomer.
2. As described in claim 1, characterized in that, The elastomer is at least one of ethylene-vinyl acetate copolymer, ethylene-octene copolymer, ethylene propylene diene monomer (EPDM) rubber, acrylate rubber, and nitrile rubber.
3. The PVC conduit according to claim 1, characterized in that, The first monomer is at least one of maleic anhydride and acrylic acid; the second monomer is at least one of styrene and methyl methacrylate.
4. The PVC conduit according to claim 1, characterized in that, The third monomer is N-cyclohexylmaleimide.
5. The PVC conduit according to claim 1, characterized in that, The preparation method of the functionalized grafted elastomer is as follows: the elastomer, the first monomer, the second monomer, the third monomer, the initiator and the processing aid are mixed evenly, and then the mixture is subjected to a melt grafting reaction through an extruder to obtain the functionalized grafted elastomer.
6. The PVC conduit according to claim 5, characterized in that, The weight ratio of the elastomer, the first monomer, the second monomer, the third monomer, the initiator and the processing aid is (80~100):(3~5):(1~5):(1~3):(0.1~0.5):(0.5~1).
7. The PVC conduit according to claim 5, characterized in that, Mix at a speed of 800 r / min to 1500 r / min for 5 min to 10 min, then melt-graft at 150℃ to 200℃ for 5 min to 10 min, with a screw speed of 100 rpm to 400 rpm.
8. The PVC conduit according to claim 5, characterized in that, The initiator is at least one of dicumyl peroxide and benzoyl peroxide.
9. The PVC conduit according to claim 1, characterized in that, The functional filler is obtained by mixing silicon carbide and hydroxyapatite in a mass ratio of (1~5):(3~9) and then modifying them.
10. A method for preparing a PVC conduit, characterized in that, The preparation method is used to prepare the PVC conduit as described in any one of claims 1 to 9, and the preparation method includes the following steps: S1. Add PVC resin, functionalized grafted elastomer, functional filler, heat stabilizer, lubricant and antioxidant to a high-speed mixer and mix evenly to obtain a mixture. S2. The mixture is added to an extruder and melted and plasticized, then extruded through a die, and after vacuum shaping, cooling, and cutting, PVC conduit is obtained.