High-strength light-weight sound-insulation flame-retardant expanded vermiculite composite plastic material and super-silence pipe thereof

Abstract

The present application relates to a kind of high-strength light-weight sound insulation flame-retardant expanded vermiculite composite plastic material and its super-silence pipe, belong to inorganic composite organic material technical field.The formula of the composite plastic material is as follows, by mass ratio, modified expanded vermiculite polymer 80~90%, long glass fiber 10~20%;Wherein the formula of modified expanded vermiculite polymer is as follows, by mass ratio, modified expanded vermiculite compound 40~55%, plastic 40~55%, maleic anhydride graft 1~8%.The super-silence drainage pipe prepared by the composite plastic material of the present application includes light wall modified expanded vermiculite polymer inner layer, composite plastic material middle layer, light wall modified expanded vermiculite polymer outer layer and inner wall spiral rib, and the inner wall spiral rib is arranged along the pipe axis 20~45°, and the finally prepared product has good sound insulation performance and flame-retardant performance.

Description

Technical Field

[0001] This invention belongs to the field of inorganic composite organic materials technology, and relates to a high-strength, lightweight, sound-insulating, flame-retardant expanded vermiculite composite plastic material and its super-quiet tube. Background Technology

[0002] Currently, polypropylene (PP) and polyethylene (PE) drainage pipes and silent pipes are widely used in building outdoor rainwater drainage risers and indoor sewage risers. Typically, outdoor rainwater risers use high-density polyethylene (HDPE) pipes, while indoor sewage risers often use three-layer co-extruded PP silent pipes, which usually have inorganic fillers such as calcium carbonate added to the PP matrix to improve performance.

[0003] However, existing technologies have significant shortcomings in application. For example, ordinary three-layer co-extruded PP silent pipes generate approximately 46-48 decibels of noise when the drainage flow rate is below 2 m / s; in high-rise or super high-rise buildings, when the full-pipe drainage flow rate exceeds 2 m / s, the noise can reach as high as 56-60 decibels, making it difficult to meet the requirements of places with high requirements for a quiet environment. Therefore, high-rise buildings are often forced to use drainage flexible cast iron pipes with noise levels of 42-46 decibels. But with people's increasing demands for the comfort of their living environment, the demand for silent pipes with drainage noise below 33 decibels, or even super silent pipes below 30 decibels, is becoming increasingly urgent in buildings such as hospitals, schools, and high-end residences. Existing drainage flexible cast iron pipes and three-layer co-extruded PP pipes cannot meet this demanding noise reduction requirement.

[0004] Natural vermiculite is a layered silicate mineral. After high-temperature roasting, the water between its layers evaporates rapidly, causing it to expand 8 to 30 times in volume, forming expanded vermiculite. The surface of the expanded vermiculite is porous and granular with microcracks, but its interior retains its original layered structure. This unique structure gives it lightweight, porous, and heat-insulating properties, making it a potentially excellent acoustic filler. The key to its application in high-performance, silent pipes lies in effectively combining it with plastics and addressing issues such as poor compatibility with the plastic matrix and potential degradation of mechanical properties. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a high-strength, lightweight, sound-insulating, flame-retardant expanded vermiculite composite plastic material. The material not only has good mechanical properties, but also excellent sound insulation and noise reduction characteristics.

[0006] Another object of the present invention is to provide a super quiet drain pipe and a quiet drain pipe made of the above-mentioned composite material. The super quiet drain pipe and the quiet drain pipe can significantly reduce drainage noise and meet stringent quiet requirements through dual optimization of materials and structure.

[0007] A high-strength, lightweight, sound-insulating, flame-retardant expanded vermiculite composite plastic material, wherein the formulation of the composite plastic material is as follows, by mass ratio: 80-90% modified expanded vermiculite polymer and 10-20% long glass fiber.

[0008] As a preferred embodiment of the present invention, the modified expanded vermiculite polymer is formulated as follows: by mass ratio, 40-55% modified expanded vermiculite composite, 40-55% plastic, and 1-8% maleic anhydride graft.

[0009] The modified expanded vermiculite composite is prepared as follows:

[0010] S2-1: Dry the expanded vermiculite in an oven at 90-100 ℃ for 2-4 hours. Add the dried expanded vermiculite to a high-speed mixer, heat to 80-90 ℃ and stir for 5-10 min. Add an ethanol solution containing 5-10% silane coupling agent to the expanded vermiculite by spraying and continue stirring for 20-30 min to obtain modified expanded vermiculite.

[0011] S2-2: Mix magnesium hydroxide powder with deionized water at a mass ratio of 1: (5~10), heat to 60~70 ℃ and stir at high speed for 1~2 h, add sodium oleate, and continue stirring for 1~2 h to obtain slurry A;

[0012] S2-3: Add modified expanded vermiculite to slurry A, stir continuously at 70~80 ℃ for 4~6 h, and then vacuum dry at 90~100 ℃ for 12 h; to obtain composite B;

[0013] S2-4: Mix complex B with 50% ethanol solution at a mass ratio of 1:10, add 3-5% tetraethyl orthosilicate by mass of complex, adjust the pH to 9-10 with ammonia water, react at 50-60 ℃ for 4-6 h, wash with deionized water and dry to obtain the modified expanded vermiculite complex.

[0014] As a preferred embodiment of the present invention, the silane coupling agent in S2-1 is one or more of KH-550, KH-560 and KH-570.

[0015] As a preferred embodiment of the present invention, the mass ratio of the ethanol solution containing 5-10% silane coupling agent to the expanded vermiculite in S2-1 is (1-2):10.

[0016] As a preferred embodiment of the present invention, the amount of sodium oleate added in S2-2 is 2 to 5% of the mass of magnesium hydroxide.

[0017] As a preferred embodiment of the present invention, the mass ratio of modified expanded vermiculite to slurry A in S2-3 is (1~3):10.

[0018] As a preferred embodiment of the present invention, the plastic is one or more of PP, PE, PVC, PA or ABS.

[0019] A method for preparing a composite plastic material, the specific steps of which are as follows:

[0020] S8-1: The mixed modified expanded vermiculite polymer is added to a twin-screw extruder for extrusion granulation according to the formula ratio. The processing temperature range of the twin-screw extruder is 180~220 ℃ and the screw speed is 300~500 rpm to obtain the modified expanded vermiculite polymer melt.

[0021] S8-2: The modified expanded vermiculite polymer melt is extruded from the feed port into the glass fiber impregnation and coating mold. The processing temperature of the twin-screw extruder is 180~220 ℃ and the screw speed is 250~350 rpm. Under the action of the LFT long glass fiber reinforced thermoplastic material production line, the composite plastic material is obtained by stretching, cooling and pelletizing.

[0022] In the preparation of the modified expanded vermiculite composite, a silane coupling agent was used to specifically modify the surface of expanded vermiculite, changing it from hydrophilic to hydrophobic, thereby improving its interfacial compatibility and adhesion with the plastic matrix. Sodium oleate was used to modify the surface of magnesium hydroxide, causing its hydrophilic ends to be directionally adsorbed onto the surface of magnesium hydroxide particles, while its hydrophobic long chains extended outwards, thus improving its dispersion in the organic system. Nanoscale magnesium hydroxide, through van der Waals forces and mechanical intercalation, was directionally attached to the surface and pore structure of micron-sized expanded vermiculite sheets, forming a micro / nano composite carrier framework. Under alkaline conditions, tetraethyl orthosilicate hydrolyzed and condensed to form a three-dimensional network structure of silica gel, which was then used to coat the surface of the composite with an amorphous layer of nano-silica particles. This silica protective layer not only improved the thermal stability of magnesium hydroxide but also further enhanced the structural integrity of the composite system through chemical bonding.

[0023] The modified expanded vermiculite composite exhibits significant sound insulation and flame retardant properties, producing a synergistic effect. Firstly, in terms of sound insulation, the modified expanded vermiculite composite constitutes a multi-scale sound energy dissipation structure. The macroscopic interlayer pores of the expanded vermiculite are responsible for blocking and reflecting sound waves; the nano-sized magnesium hydroxide and silica particles loaded on its surface create a vast number of microscopic interfaces, causing intense scattering and friction of sound waves, significantly enhancing the dissipation capacity for mid-to-low frequency noise. The noise reduction effect is significantly superior to that of simply mixed filler systems.

[0024] In terms of flame retardancy, the modified expanded vermiculite composite forms a synergistic flame retardant mechanism, in which magnesium hydroxide decomposes and absorbs heat and releases water vapor; expanded vermiculite expands further after being heated to form an insulating layer; and the silica protective layer, together with the decomposition products, generates a more robust and dense ceramicized carbon layer during combustion, further improving the flame retardant efficiency and smoke suppression effect.

[0025] The formulation system of this invention achieves performance balance through the complementarity of rigidity and flexibility and interface optimization. Long glass fibers construct a three-dimensional reinforcing network, whose axial tensile strength effectively compensates for the rigidity loss caused by the addition of vermiculite, helping to maintain the elastic modulus of the material. Expanded vermiculite reduces the material density through the lamellar barrier effect, while its porous structure adsorbs resin molecular chains, alleviating the increase in brittleness caused by the introduction of glass fibers. Maleic anhydride grafted plastic is a reactive compatibilizer that can react with the modified expanded vermiculite composite and physically entangle the plastic molecular chains, further enhancing the interfacial bonding strength between expanded vermiculite and the plastic matrix and promoting the dispersion of the composite in the matrix. Based on the synergistic effect of coupling agent and compatibilizer, the physical and mechanical properties of the composite plastic are improved, and the tensile strength, flexural strength, impact strength and heat distortion temperature of the composite plastic are increased.

[0026] A super-quiet drainage pipe made of the composite plastic material, the super-quiet drainage pipe comprising an inner layer of smooth-wall modified expanded vermiculite polymer, a middle layer of composite plastic material, an outer layer of smooth-wall modified expanded vermiculite polymer, and inner wall spiral ribs.

[0027] The spiral ribs are arranged at 20-45° along the pipe axis and guide the drainage in the pipe to flow down the spiral wall, reducing the noise, sound distortion and air friction noise generated by the friction between the water and the pipe wall, reducing the noise by 10-15 decibels. The layered structure of expanded vermiculite in the middle layer of the composite plastic material blocks the penetration of noise in the pipe. The expanded vermiculite converts sound energy into heat energy through the air gap between the layers. The gaps cause the sound waves to undergo multiple reflections, refractions and scattering after entering, and the energy is greatly consumed, reducing the noise by 10-12 decibels. The long glass fiber in this layer is a high-density and high-rigidity material, which greatly improves the weight and rigidity of the pipe wall, thereby achieving a noise reduction of 5-6 decibels.

[0028] A silent drainage pipe made of the aforementioned composite plastic material comprises an inner layer of smooth-walled modified expanded vermiculite polymer, a middle layer of composite plastic material, and an outer layer of smooth-walled modified expanded vermiculite polymer. The smooth-walled inner layer reduces water flow buildup on the pipe wall, lowering the initial noise source intensity; the middle layer of composite plastic material achieves multi-frequency noise blocking and dissipation; and the smooth-walled outer layer suppresses the outward propagation of micro-vibrations from the middle layer while simultaneously improving the pipe's ring stiffness. This silent drainage pipe can meet the noise level requirement of less than 33 decibels in a high-end bedroom at night.

[0029] The beneficial effects of this invention are:

[0030] (1) The formulation of this invention first modifies expanded vermiculite with silane coupling agent to form a hydrophobic interface, and modifies magnesium hydroxide with sodium oleate to construct a micro-nano composite carrier. Tetraethyl orthosilicate hydrolyzes and coats the silica gel layer, which significantly improves the compatibility and structural stability of the composite with the plastic matrix. The macroscopic interlayer pores of modified vermiculite block sound waves, and the loaded nanoparticles dissipate low- and mid-frequency noise efficiently through scattering and friction. The synergistic effect of long glass fiber mass effect achieves wide-band noise reduction. In terms of flame retardancy, the endothermic decomposition of magnesium hydroxide, the expansion and heat insulation of vermiculite, and the ceramic carbonization of silica work synergistically to further improve the flame retardancy efficiency. The three-dimensional network of long glass fiber compensates for the rigidity loss of vermiculite, the porous structure of vermiculite alleviates the brittleness of glass fiber, and the dual effect of compatibilizer strengthens the interface, ultimately enabling the material to achieve the characteristics of lightweight, high strength, sound insulation and flame retardancy.

[0031] (2) The super silent drainage pipe of this invention achieves noise reduction performance through structural innovation and material synergy. The spiral ribs on the inner wall of the super silent drainage pipe guide the water flow in a spiral direction, reducing turbulent friction noise. Combined with the micro-nano porous structure of the inner and outer layers, it further absorbs high-frequency noise. The expanded vermiculite sheet layer in the middle layer reflects and refracts sound waves through the air gap layer, and the long glass fiber reinforcement layer uses the mass law to block low-frequency noise, which together reduces the radiated noise of the pipe. The three-layer structure of the silent drainage pipe has a clear division of labor: the inner smooth wall reduces water flow from sticking to the wall, the middle composite material blocks sound waves and dissipates energy through the macroscopic pores of vermiculite and the scattering of nanoparticles, and the outer smooth wall inhibits vibration transmission and improves ring stiffness, resulting in a significant improvement in overall noise reduction performance. Attached Figure Description

[0032] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0033] Figure 1 This is a structural diagram of the super-quiet drainage pipe prepared from the composite plastic material obtained in Example 1 of the present invention;

[0034] Explanation of key component symbols:

[0035] In the figure: 1. Inner layer of smooth-wall modified expanded vermiculite polymer; 2. Middle layer of composite plastic material; 3. Outer layer of smooth-wall modified expanded vermiculite polymer; 4. Inner wall spiral ribs. Detailed Implementation

[0036] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided.

[0037] Example 1

[0038] A high-strength, lightweight, sound-insulating, flame-retardant expanded vermiculite composite plastic material, wherein the formulation of the composite plastic material is as follows, by mass ratio: 85% modified expanded vermiculite polymer and 15% long glass fiber.

[0039] The formulation of the modified expanded vermiculite polymer is as follows: by mass ratio, the modified expanded vermiculite composite is 48%, plastic is 48%, and PP-g-MAH compatibilizer is 4%, wherein the plastic is a mixture of 70% PP and 30% HDPE.

[0040] The modified expanded vermiculite composite is prepared as follows:

[0041] S2-1: Dry the expanded vermiculite in an oven at 95 ℃ for 3 h. Add the dried expanded vermiculite to a high-speed mixer, heat to 85 0 ℃ and stir for 5-10 min. Add an ethanol solution containing 8% silane coupling agent KH-550 to the expanded vermiculite by spraying. The mass ratio of the ethanol solution containing 8% silane coupling agent to the expanded vermiculite is 1.5:10. Continue stirring for 25 min to obtain modified expanded vermiculite.

[0042] S2-2: Mix magnesium hydroxide powder with deionized water at a mass ratio of 1:8, heat to 65 ℃ and stir at high speed for 1.5 h, add sodium oleate at 3.5% of the mass of magnesium hydroxide, and continue stirring for 1.5 h to obtain slurry A;

[0043] S2-3: Modified expanded vermiculite was added to slurry A at a mass ratio of 1:5. The mixture was stirred continuously at 75°C for 5 h, and then vacuum dried at 95°C for 12 h to obtain composite B.

[0044] S2-4: Mix complex B with 50% ethanol solution at a mass ratio of 1:10, add 4% tetraethyl orthosilicate by mass of complex, adjust the pH to 9.5 with ammonia water, react at 55 ℃ for 5 h, wash with deionized water and dry to obtain the modified expanded vermiculite complex.

[0045] A method for preparing a composite plastic material, the specific steps of which are as follows:

[0046] S8-1: The mixed modified expanded vermiculite polymer is added to a twin-screw extruder for extrusion granulation according to the formula ratio. The processing temperature range of the twin-screw extruder is 200 ℃ and the screw speed is 400 rpm to obtain the modified expanded vermiculite polymer melt.

[0047] S8-2: The modified expanded vermiculite polymer melt is extruded from the feed port into the glass fiber impregnation and coating mold. The twin-screw extruder has a processing temperature of 200 ℃ and a screw speed of 300 rpm. Under the action of the LFT long glass fiber reinforced thermoplastic material production line, the material is drawn into strips, cooled, and pelletized to obtain the composite plastic material.

[0048] A super-quiet drainage pipe made of the composite plastic material, the super-quiet drainage pipe comprising an inner layer of smooth-wall modified expanded vermiculite polymer (5 mm), a middle layer of composite plastic material (4 mm thick), an outer layer of smooth-wall modified expanded vermiculite polymer (5 mm), and inner wall spiral ribs (spiral rib angle 30°, pitch 50 mm).

[0049] Example 2

[0050] A high-strength, lightweight, sound-insulating, flame-retardant expanded vermiculite composite plastic material, wherein the formulation of the composite plastic material is as follows, by mass ratio: 80% modified expanded vermiculite polymer and 20% long glass fiber.

[0051] The formulation of the modified expanded vermiculite polymer is as follows, by mass ratio: 49% modified expanded vermiculite composite, 49% plastic, and 2% PP-g-MAH compatibilizer; wherein the plastic is a mixture of 70% PP and 30% HDPE.

[0052] The modified expanded vermiculite composite is prepared as follows:

[0053] S2-1: Dry the expanded vermiculite in an oven at 90 ℃ for 2 h. Add the dried expanded vermiculite to a high-speed mixer, heat to 80 ℃ and stir for 5 min. Add an ethanol solution containing 5% silane coupling agent KH-560 to the expanded vermiculite by spraying. The mass ratio of the ethanol solution containing 5% silane coupling agent to the expanded vermiculite is 1:10. Continue stirring for 20 min to obtain modified expanded vermiculite.

[0054] S2-2: Mix magnesium hydroxide powder with deionized water at a mass ratio of 1:5, heat to 60 ℃ and stir at high speed for 1 h, add sodium oleate at 2% of the mass of magnesium hydroxide, and continue stirring for 1 h to obtain slurry A;

[0055] S2-3: Modified expanded vermiculite was added to slurry A at a mass ratio of 1:10. The mixture was stirred continuously at 70°C for 4 h, and then vacuum dried at 90°C for 12 h to obtain composite B.

[0056] S2-4: Mix complex B with 50% ethanol solution at a mass ratio of 1:10, add 3% tetraethyl orthosilicate by mass of complex, adjust pH to 9 with ammonia, react at 50 °C for 4 h, wash with deionized water and dry to obtain the modified expanded vermiculite complex.

[0057] A method for preparing a composite plastic material, the specific steps of which are as follows:

[0058] S8-1: The mixed modified expanded vermiculite polymer is added to a twin-screw extruder for extrusion granulation according to the formula ratio. The processing temperature range of the twin-screw extruder is 180 ℃ and the screw speed is 300 rpm to obtain the modified expanded vermiculite polymer melt.

[0059] S8-2: The modified expanded vermiculite polymer melt is extruded from the feed port into the glass fiber impregnation and coating mold. The twin-screw extruder has a processing temperature of 180 ℃ and a screw speed of 250 rpm. Under the action of the LFT long glass fiber reinforced thermoplastic material production line, the composite plastic material is obtained by stretching, cooling and pelletizing.

[0060] The preparation steps and parameters of the super silent drainage pipe are the same as those in Example 1.

[0061] Example 3

[0062] A high-strength, lightweight, sound-insulating, flame-retardant expanded vermiculite composite plastic material, wherein the formulation of the composite plastic material is as follows, by mass ratio: 89% modified expanded vermiculite polymer and 11% long glass fiber.

[0063] The formulation of the modified expanded vermiculite polymer is as follows, by mass ratio: 46% modified expanded vermiculite composite, 46% plastic, and 8% PP-g-MAH compatibilizer; wherein the plastic is a mixture of 70% PP and 30% HDPE.

[0064] The modified expanded vermiculite composite is prepared as follows:

[0065] S2-1: Dry the expanded vermiculite in an oven at 100 ℃ for 4 h. Add the dried expanded vermiculite to a high-speed mixer, heat to 90 ℃ and stir for 10 min. Add an ethanol solution containing 10% silane coupling agent KH-570 to the expanded vermiculite by spraying. The mass ratio of the ethanol solution containing 10% silane coupling agent to the expanded vermiculite is 1:5. Continue stirring for 30 min to obtain modified expanded vermiculite.

[0066] S2-2: Mix magnesium hydroxide powder with deionized water at a mass ratio of 1:10, heat to 70 ℃ and stir at high speed for 2 hours, add sodium oleate at 5% of the mass of magnesium hydroxide, and continue stirring for 2 hours to obtain slurry A;

[0067] S2-3: Modified expanded vermiculite was added to slurry A at a mass ratio of 3:10. The mixture was stirred continuously at 80°C for 6 h and then vacuum dried at 100°C for 12 h to obtain composite B.

[0068] S2-4: Mix complex B with 50% ethanol solution at a mass ratio of 1:10, add 5% tetraethyl orthosilicate by mass of complex, adjust pH to 10 with ammonia water, react at 60 ℃ for 6 h, wash with deionized water and dry to obtain the modified expanded vermiculite complex.

[0069] A method for preparing a composite plastic material, the specific steps of which are as follows:

[0070] S8-1: The mixed modified expanded vermiculite polymer is added to a twin-screw extruder for extrusion granulation according to the formula ratio. The processing temperature range of the twin-screw extruder is 220 ℃ and the screw speed is 500 rpm to obtain the modified expanded vermiculite polymer melt.

[0071] S8-2: The modified expanded vermiculite polymer melt is extruded from the feed port into the glass fiber impregnation and coating mold. The twin-screw extruder has a processing temperature of 220 ℃ and a screw speed of 350 rpm. Under the action of the LFT long glass fiber reinforced thermoplastic material production line, the composite plastic material is obtained by stretching, cooling and pelletizing.

[0072] The preparation steps and parameters of the super silent drainage pipe are the same as those in Example 1.

[0073] Comparative Example 1

[0074] Untreated expanded vermiculite was used instead of the modified expanded vermiculite composite, and the other steps were the same as in Example 1.

[0075] Comparative Example 2

[0076] No silane coupling agent was added in the preparation of the modified expanded vermiculite composite, and the other steps were the same as in Example 1.

[0077] Comparative Example 3

[0078] Sodium hydroxide was not added in the preparation of the modified expanded vermiculite composite, and the other steps were the same as in Example 1.

[0079] Comparative Example 4

[0080] Sodium oleate was not added in the preparation of the modified expanded vermiculite composite, and the other steps were the same as in Example 1.

[0081] Comparative Example 5

[0082] In the preparation of the modified expanded vermiculite composite, tetraethyl orthosilicate was not added, and the other steps were the same as in Example 1.

[0083] Comparative Example 6

[0084] Without adding long glass fibers, the other steps are the same as in Example 1.

[0085] Comparative Example 7

[0086] Without adding PP-g-MAH compatibilizer, the other steps are the same as in Example 1.

[0087] Comparative Example 8

[0088] The preparation of the super silent drain pipe does not include spiral ribs, and the other steps are the same as in Example 1.

[0089] Performance testing

[0090] The sound insulation performance of the examples and comparative data was tested in accordance with the standard GB / T 19889.3-2005; the flame retardant performance of the examples and comparative data was tested in accordance with the standard GB / T 2406.2-2009.

[0091]

[0092] As can be seen from the examples and comparative data, the material prepared by the present invention has good sound insulation and flame retardant properties.

[0093] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A high-strength, lightweight, sound-insulating, flame-retardant, expanded vermiculite composite plastic material, characterized in that, The formulation of the composite plastic material is as follows, by mass ratio: 80-90% modified expanded vermiculite polymer and 10-20% long glass fiber; The formulation of the modified expanded vermiculite polymer is as follows, by mass ratio: 40-55% modified expanded vermiculite composite, 40-55% plastic, and 1-8% maleic anhydride graft. The modified expanded vermiculite composite is prepared as follows: S2-1: Dry the expanded vermiculite in an oven at 90-100 ℃ for 2-4 hours. Add the dried expanded vermiculite to a high-speed mixer, heat to 80-90 ℃ and stir for 5-10 min. Add an ethanol solution containing 5-10% silane coupling agent to the expanded vermiculite by spraying and continue stirring for 20-30 min to obtain modified expanded vermiculite. S2-2: Mix magnesium hydroxide powder with deionized water at a mass ratio of 1: (5~10), heat to 60~70 ℃ and stir at high speed for 1~2 h, add sodium oleate, and continue stirring for 1~2 h to obtain slurry A; S2-3: Add modified expanded vermiculite to slurry A, stir continuously at 70~80 ℃ for 4~6 h, and then vacuum dry at 90~100 ℃ for 12 h to obtain composite B; S2-4: Mix complex B with 50% ethanol solution at a mass ratio of 1:10, add 3-5% tetraethyl orthosilicate by mass of complex, adjust the pH to 9-10 with ammonia water, react at 50-60 ℃ for 4-6 h, wash with deionized water and dry to obtain the modified expanded vermiculite complex.

2. The high-strength, lightweight, sound-insulating, flame-retardant, expanded vermiculite composite plastic material according to claim 1, characterized in that, The silane coupling agent in S2-1 is one or more of KH-550, KH-560 and KH-570.

3. The high-strength, lightweight, sound-insulating, flame-retardant, expanded vermiculite composite plastic material according to claim 1, characterized in that, The mass ratio of the ethanol solution containing 5-10% silane coupling agent to expanded vermiculite in S2-1 is (1-2):

10.

4. The high-strength, lightweight, sound-insulating, flame-retardant, expanded vermiculite composite plastic material according to claim 1, characterized in that, The amount of sodium oleate added in S2-2 is 2-5% of the mass of magnesium hydroxide.

5. The high-strength, lightweight, sound-insulating, flame-retardant, expanded vermiculite composite plastic material according to claim 1, characterized in that, The mass ratio of modified expanded vermiculite to slurry A in S2-3 is (1~3):

10.

6. The high-strength, lightweight, sound-insulating, flame-retardant, expanded vermiculite composite plastic material according to claim 1, characterized in that, The plastic is one or more of PP, PE, PVC, PA or ABS.

7. A method for preparing a composite plastic material as described in any one of claims 1 to 6, characterized in that, The specific steps of the preparation method are as follows: S8-1: The mixed modified expanded vermiculite polymer is added to a twin-screw extruder for extrusion granulation according to the formula ratio. The processing temperature range of the twin-screw extruder is 180~220 ℃ and the screw speed is 300~500 rpm to obtain modified expanded vermiculite polymer particles. S8-2: Modified expanded vermiculite polymer particles are added to the feed port of a twin-screw extruder and extruded into a glass fiber impregnation and coating die. The twin-screw extruder has a processing temperature of 180~220 ℃ and a screw speed of 250~350 rpm. Under the action of the LFT long glass fiber reinforced thermoplastic material production line, the material is obtained by stretching, cooling and pelletizing.

8. A drainage pipe with high strength, lightweight, sound insulation, and flame retardant properties prepared from the composite plastic material as described in any one of claims 1 to 6, characterized in that, The drainage pipe includes an inner layer of smooth-wall modified expanded vermiculite polymer, a middle layer of composite plastic material, an outer layer of smooth-wall modified expanded vermiculite polymer, and inner wall spiral ribs, the inner wall spiral ribs being arranged at 20~45° along the pipe axis.

9. A drainage pipe with high strength, lightweight, sound-absorbing, and flame-retardant properties, prepared from the composite plastic material as described in any one of claims 1 to 6, characterized in that, The drainage pipe comprises an inner layer of smooth-walled modified expanded vermiculite polymer, a middle layer of composite plastic material, and an outer layer of smooth-walled modified expanded vermiculite polymer.

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