Polypropylene corrugated pipe composite material and preparation method of composite polypropylene corrugated pipe

Abstract

The invention discloses a polypropylene corrugated pipe composite material and a preparation method of a composite polypropylene corrugated pipe, and the polypropylene corrugated pipe composite material is prepared from the following raw materials in parts by weight: 90-100 parts of polypropylene, 15-20 parts of modified talcum powder, 2-3 parts of a compatilizer, 0.5-1 part of a lubricant and 0.5-0.8 part of an antioxidant. According to the polypropylene corrugated pipe composite material disclosed by the invention, rigid pyromellitic dianhydride and flexible castor oil are sequentially grafted on the surface of talcum powder, so that the obtained modified talcum powder has multiple functions of interface compatibility, heterogeneous nucleation, rigidity enhancement, flexible toughening and the like, and then the modified talcum powder is added into a polypropylene matrix as a functional filler; the polypropylene corrugated pipe composite material has the advantages of high ring stiffness, excellent toughness and impact resistance, simple formula and clear process route, and the prepared corrugated pipe has excellent comprehensive performance and high industrial application value.

Description

Technical Field

[0001] This invention belongs to the field of high-performance polypropylene materials technology, specifically relating to a polypropylene corrugated pipe composite material and a method for preparing a composite polypropylene corrugated pipe. Background Technology

[0002] Polypropylene is widely used in the production of various pipe products due to its excellent chemical resistance, good processing performance, low density, and cost advantage. Among them, polypropylene corrugated pipes, especially double-wall corrugated pipes, have become an indispensable key material in municipal drainage, sewage, and communication cable sheathing fields, thanks to their unique annular corrugated structure, which maintains high ring stiffness while keeping material consumption low.

[0003] With increasingly stringent engineering application requirements, the market has set higher standards for the performance of polypropylene corrugated pipes, especially in terms of ring stiffness, impact resistance, and long-term service life. Pure polypropylene materials have limited rigidity and toughness, making it difficult to fully meet the requirements of high-level engineering standards (such as SN8 and SN16 levels). Therefore, modifying polypropylene to improve its overall performance has become a technological development trend in this field.

[0004] Among numerous modification methods, inorganic mineral filling modification is an economical and efficient technique. Talc, as a common layered silicate filler, is often used to fill polypropylene to improve its flexural modulus and dimensional stability due to its low price, plate-like structure, and high rigidity, thereby effectively enhancing the ring stiffness of bellows.

[0005] However, traditional talc-filled polypropylene technology has long suffered from a technical bottleneck that has remained unresolved: the inherently poor compatibility between the inorganic filler and the non-polar polypropylene matrix. Talc is hydrophilic and polar, while polypropylene is hydrophobic and non-polar, resulting in weak interfacial bonding, much like oil and water. This weak interface leads to a series of problems, such as deterioration of mechanical properties. Under impact, the weak interface is prone to debonding, becoming a stress concentration point, causing a sharp decrease in the material's impact toughness, tensile strength, and elongation at break. This makes corrugated pipes particularly susceptible to brittle fracture at low temperatures, seriously affecting engineering safety. Furthermore, it is difficult to balance stiffness and toughness; increasing the talc filler content to improve ring stiffness inevitably sacrifices toughness, and vice versa.

[0006] To improve the interfacial compatibility between talc and polypropylene, those skilled in the art have made various attempts. For example, surface treatment of talc is performed using titanate or aluminate coupling agents, or compatibilizers such as maleic anhydride-grafted polypropylene are added to the formulation. These methods improve the interfacial bonding to some extent, but the effects are limited and cannot fundamentally solve the deep-seated contradiction between rigidity and toughness.

[0007] Therefore, it is of great significance to develop a new type of polypropylene corrugated pipe composite material to achieve a simultaneous and significant improvement in the rigidity and toughness of polypropylene materials. Summary of the Invention

[0008] In view of the shortcomings of the prior art, the purpose of this invention is to provide a polypropylene corrugated pipe composite material and a method for preparing a composite polypropylene corrugated pipe.

[0009] To achieve the above objectives, the present invention provides the following technical solution:

[0010] A polypropylene corrugated pipe composite material, comprising the following raw materials by weight:

[0011] 90-100 parts polypropylene, 15-20 parts modified talc, 2-3 parts compatibilizer, 0.5-1 part lubricant, and 0.5-0.8 parts antioxidant.

[0012] Preferably, a polypropylene corrugated pipe composite material comprises, by weight, the following raw materials:

[0013] 95-100 parts polypropylene, 17-20 parts modified talc, 2.5-3 parts compatibilizer, 0.7-1 part lubricant, and 0.5-0.7 parts antioxidant.

[0014] Preferably, the method for preparing the modified talc powder includes the following steps:

[0015] S1. Add talc powder to an aqueous ethanol solution, then add γ-aminopropyltrimethoxysilane, stir and react. After the reaction is complete, filter, wash and dry to obtain amino-modified talc powder.

[0016] S2. Add the aminoated talc powder from step S1 to dimethylacetamide, then add pyromellitic dianhydride, and carry out a constant temperature reaction. After the reaction is completed, filter, wash, and dry to obtain functionalized talc powder.

[0017] S3. Add the functionalized talc powder from step S2 to dimethylacetamide, then add castor oil and dibutyltin dilaurate, and heat the mixture to react. After the reaction is complete, filter, wash, and dry to obtain modified talc powder.

[0018] In this invention, talc is used as an inorganic core, and active amino groups are introduced into the talc by reacting it with γ-aminopropyltrimethoxysilane, which is beneficial for subsequent reactions. Then, pyromellitic dianhydride is added, and the rigid pyromellitic dianhydride molecules are firmly anchored to the surface of the talc by reacting with the amino groups. This not only effectively improves the modulus and ring stiffness of the polypropylene corrugated pipe composite, but also provides reaction sites for subsequent reactions. Finally, castor oil containing three fatty acid chains with up to 18 carbon atoms is introduced into the talc by reacting with the anhydride and hydroxyl groups. Its long carbon chain structure significantly improves the impact toughness of the material by forming a physical entanglement network with the polypropylene matrix and improving interfacial compatibility. Through the synergistic effect of pyromellitic dianhydride and castor oil, the polypropylene corrugated pipe composite has better comprehensive performance.

[0019] Preferably, in step S1, the volume ratio of ethanol to water in the aqueous ethanol solution is 8-9:1-2, the mass ratio of talc to γ-aminopropyltrimethoxysilane is 100:6-9, and the stirring reaction temperature is 65-75℃ for 3-5 hours.

[0020] Preferably, in step S2, the mass ratio of the aminated talc to the pyromellitic dianhydride is 100:20-30, and the isothermal reaction is carried out at a temperature of 40-60°C for 4-6 hours.

[0021] Preferably, in step S3, the mass ratio of functionalized talc, castor oil, and dibutyltin dilaurate is 100:15-25:0.1-0.2, and the heating reaction temperature is 130-140℃ for 5-7 hours.

[0022] Preferably, the lubricant is one or more of erucamide, calcium stearate, and ethylene bis-stearamide, the compatibilizer is maleic anhydride-grafted polypropylene, and the antioxidant is composed of antioxidant 1098 and antioxidant 168 in a mass ratio of 2:1.

[0023] This invention also protects a method for preparing the polypropylene corrugated pipe composite material as described above, comprising the following steps:

[0024] Weigh the raw materials according to the formula, premix the polypropylene, modified talc, compatibilizer, lubricant and antioxidant in a high-speed mixer until uniform, and then add them to a twin-screw extruder. After melt blending, extrusion and pelletizing, the polypropylene corrugated pipe composite material is obtained.

[0025] Preferably, the processing temperatures of each zone of the twin-screw extruder are set as follows: Zone 1 170-190℃, Zone 2 180-200℃, Zone 3 190-210℃, Zone 4 200-220℃, Zone 5 200-220℃, and Die head 210-230℃; the main engine speed of the twin-screw extruder is 300-500 rpm.

[0026] This invention also protects a composite polypropylene corrugated pipe prepared from the polypropylene corrugated pipe composite material described above.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] (1) The polypropylene corrugated pipe composite material provided by the present invention is obtained by grafting rigid pyromellitic dianhydride and flexible castor oil onto the surface of talc powder in sequence. The modified talc powder has multiple functions such as interfacial compatibility, heterogeneous nucleation, rigidity enhancement and flexibility toughening. Subsequently, it is added to the polypropylene matrix as a functional filler, so that the obtained polypropylene corrugated pipe composite material not only has high ring stiffness, but also excellent toughness and impact resistance. It effectively solves the technical problem that traditional high-filled polypropylene materials cannot achieve both rigidity and toughness. The composite material has a simple formula and a clear process route. The corrugated pipe prepared has excellent comprehensive performance and has high industrial application value.

[0029] (2) The polypropylene corrugated pipe composite material provided by the present invention, in which modified talc powder is prepared, introduces pyromellitic dianhydride and castor oil sequentially through chemical bonding. In step S2, at a relatively low constant temperature, the reaction between the anhydride and the amino group is utilized, and an excess of pyromellitic dianhydride is added to ensure single-arm grafting of the pyromellitic dianhydride. In step S3, the reaction is carried out at a higher temperature with the aid of an esterification catalyst, so that the anhydride reacts with the hydroxyl groups in the castor oil, effectively avoiding the occurrence of side reactions, and making the final product have high stability and repeatability. Among them, the introduced pyromellitic dianhydride can not only be used as The modified talc, while serving as a connecting skeleton, effectively enhances the modulus of the interface between the filler and the polymer matrix through its rigid benzene ring structure. It also acts as an excellent heterogeneous nucleating agent template, promoting polypropylene crystallization and providing the material with high ring stiffness. The three long fatty acid chains in the subsequently grafted castor oil act as non-polar compatibility arms, forming a robust physical entanglement network with the polypropylene matrix. This modified talc achieves synergistic effects between rigid and flexible units through chemical bonds, fundamentally improving the interfacial bonding between the inorganic filler and the organic matrix. This results in more efficient stress transfer in the composite material, significantly enhancing its tear resistance and impact toughness.

[0030] (3) The polypropylene corrugated pipe composite material provided by the present invention uses maleic anhydride-grafted polypropylene as a compatibilizer. Its anhydride group can react with the residual polar groups (such as hydroxyl or carboxyl groups) that may exist on the surface of modified talc powder to enhance the interfacial bonding effect. At the same time, the use of lubricant effectively reduces the friction between the high-fill melt and the processing equipment, improves the melt flowability, avoids material degradation caused by local shear overheating, ensures the stable production of the composite material in the twin-screw extrusion and subsequent corrugated pipe forming process, and improves the surface smoothness of the final product. Detailed Implementation

[0031] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0032] Unless otherwise specified, all chemical reagents and materials in this invention are purchased from the market or synthesized from raw materials purchased from the market.

[0033] In this invention, the polypropylene is grade PPH-T03, and the talc has a particle size of 5-10 μm.

[0034] Example 1

[0035] A polypropylene corrugated pipe composite material, comprising the following raw materials by weight:

[0036] 95 parts polypropylene, 18 parts modified talc, 2.5 parts compatibilizer, 0.8 parts lubricant, and 0.7 parts antioxidant.

[0037] The method for preparing the modified talc powder includes the following steps:

[0038] S1. Add 100g of talc powder to 800mL of ethanol-water solution (ethanol to water volume ratio of 9:1), then add 8g of γ-aminopropyltrimethoxysilane, stir at 70℃ for 4h, filter, wash and dry after the reaction is complete to obtain amino-modified talc powder.

[0039] S2. Add 100g of amino-modified talc powder to 1L of dimethylacetamide, then add 25g of pyromellitic dianhydride, and react at 50℃ for 5h. After the reaction is complete, filter, wash and dry to obtain functionalized talc powder.

[0040] S3. Add 100g of functionalized talc powder to 1L of dimethylacetamide, then add 20g of castor oil and 0.15g of dibutyltin dilaurate, and react at 135℃ for 6h. After the reaction is complete, filter, wash and dry to obtain modified talc powder.

[0041] The lubricant is erucamide, the compatibilizer is maleic anhydride-grafted polypropylene, and the antioxidant is composed of antioxidant 1098 and antioxidant 168 in a mass ratio of 2:1.

[0042] A method for preparing a polypropylene corrugated pipe composite material includes the following steps:

[0043] Weigh the raw materials according to the formula, premix the polypropylene, modified talc, compatibilizer, lubricant and antioxidant in a high-speed mixer until uniform, and then add them to a twin-screw extruder. After melt blending, extrusion and pelletizing, the polypropylene corrugated pipe composite material is obtained.

[0044] The processing temperatures of each zone of the twin-screw extruder are set as follows: Zone 1 180℃, Zone 2 190℃, Zone 3 200℃, Zone 4 210℃, Zone 5 220℃, and Die Head 215℃; the main engine speed of the twin-screw extruder is 400 rpm.

[0045] Example 2

[0046] A polypropylene corrugated pipe composite material, comprising the following raw materials by weight:

[0047] 100 parts polypropylene, 20 parts modified talc, 3 parts compatibilizer, 1 part lubricant, and 0.8 parts antioxidant.

[0048] The method for preparing the modified talc powder includes the following steps:

[0049] S1. Add 100g of talc powder to 800mL of ethanol aqueous solution (ethanol to water volume ratio of 8.5:1.5), then add 6g of γ-aminopropyltrimethoxysilane, stir at 75℃ for 3h, filter, wash and dry after the reaction is complete to obtain amino-modified talc powder.

[0050] S2. Add 100g of amino-modified talc powder to 1L of dimethylacetamide, then add 20g of pyromellitic dianhydride, and react at 60℃ for 4h. After the reaction is complete, filter, wash and dry to obtain functionalized talc powder.

[0051] S3. Add 100g of functionalized talc powder to 1L of dimethylacetamide, then add 15g of castor oil and 0.1g of dibutyltin dilaurate, and react at 140℃ for 5h. After the reaction is completed, filter, wash and dry to obtain modified talc powder.

[0052] The lubricant is calcium stearate, the compatibilizer is maleic anhydride-grafted polypropylene, and the antioxidant is composed of antioxidant 1098 and antioxidant 168 in a mass ratio of 2:1.

[0053] A method for preparing a polypropylene corrugated pipe composite material includes the following steps:

[0054] Weigh the raw materials according to the formula, premix the polypropylene, modified talc, compatibilizer, lubricant and antioxidant in a high-speed mixer until uniform, and then add them to a twin-screw extruder. After melt blending, extrusion and pelletizing, the polypropylene corrugated pipe composite material is obtained.

[0055] The processing temperatures of each zone of the twin-screw extruder are set as follows: Zone 1 180℃, Zone 2 190℃, Zone 3 200℃, Zone 4 210℃, Zone 5 220℃, and Die Head 215℃; the main engine speed of the twin-screw extruder is 400 rpm.

[0056] Example 3

[0057] A polypropylene corrugated pipe composite material, comprising the following raw materials by weight:

[0058] 90 parts polypropylene, 15 parts modified talc, 2 parts compatibilizer, 0.5 parts lubricant, and 0.5 parts antioxidant.

[0059] The method for preparing the modified talc powder includes the following steps:

[0060] S1. Add 100g of talc powder to 800mL of ethanol aqueous solution (ethanol to water volume ratio of 8:2), then add 9g of γ-aminopropyltrimethoxysilane, stir at 65℃ for 5h, filter, wash and dry after the reaction is completed to obtain amino-modified talc powder.

[0061] S2. Add 100g of amino-modified talc powder to 1L of dimethylacetamide, then add 30g of pyromellitic dianhydride, and react at 40℃ for 6h. After the reaction is complete, filter, wash and dry to obtain functionalized talc powder.

[0062] S3. Add 100g of functionalized talc powder to 1L of dimethylacetamide, then add 25g of castor oil and 0.2g of dibutyltin dilaurate, and react at 130℃ for 7h. After the reaction is completed, filter, wash and dry to obtain modified talc powder.

[0063] The lubricant is ethylene bis-stearamide, the compatibilizer is maleic anhydride-grafted polypropylene, and the antioxidant is composed of antioxidant 1098 and antioxidant 168 in a mass ratio of 2:1.

[0064] A method for preparing a polypropylene corrugated pipe composite material includes the following steps:

[0065] Weigh the raw materials according to the formula, premix the polypropylene, modified talc, compatibilizer, lubricant and antioxidant in a high-speed mixer until uniform, and then add them to a twin-screw extruder. After melt blending, extrusion and pelletizing, the polypropylene corrugated pipe composite material is obtained.

[0066] The processing temperatures of each zone of the twin-screw extruder are set as follows: Zone 1 180℃, Zone 2 190℃, Zone 3 200℃, Zone 4 210℃, Zone 5 220℃, and Die Head 215℃; the main engine speed of the twin-screw extruder is 400 rpm.

[0067] Example 4

[0068] A polypropylene corrugated pipe composite material, comprising the following raw materials by weight:

[0069] 93 parts polypropylene, 17 parts modified talc, 2.3 parts compatibilizer, 0.7 parts lubricant, and 0.6 parts antioxidant.

[0070] The method for preparing the modified talc powder includes the following steps:

[0071] S1. Add 100g of talc powder to 800mL of ethanol aqueous solution (ethanol to water volume ratio of 8:2), then add 7g of γ-aminopropyltrimethoxysilane, stir at 70℃ for 4h, filter, wash and dry after the reaction is completed to obtain amino-modified talc powder.

[0072] S2. Add 100g of amino-modified talc powder to 1L of dimethylacetamide, then add 27g of pyromellitic dianhydride, and react at 50℃ for 5h. After the reaction is complete, filter, wash and dry to obtain functionalized talc powder.

[0073] S3. Add 100g of functionalized talc powder to 1L of dimethylacetamide, then add 22g of castor oil and 0.25g of dibutyltin dilaurate, and react at 135℃ for 6h. After the reaction is complete, filter, wash and dry to obtain modified talc powder.

[0074] The lubricant is ethylene bis-stearamide, the compatibilizer is maleic anhydride-grafted polypropylene, and the antioxidant is composed of antioxidant 1098 and antioxidant 168 in a mass ratio of 2:1.

[0075] A method for preparing a polypropylene corrugated pipe composite material includes the following steps:

[0076] Weigh the raw materials according to the formula, premix the polypropylene, modified talc, compatibilizer, lubricant and antioxidant in a high-speed mixer until uniform, and then add them to a twin-screw extruder. After melt blending, extrusion and pelletizing, the polypropylene corrugated pipe composite material is obtained.

[0077] The processing temperatures of each zone of the twin-screw extruder are set as follows: Zone 1 180℃, Zone 2 190℃, Zone 3 200℃, Zone 4 210℃, Zone 5 220℃, and Die Head 215℃; the main engine speed of the twin-screw extruder is 400 rpm.

[0078] Comparative Example 1

[0079] A polypropylene corrugated pipe composite material, comprising the following raw materials by weight:

[0080] 95 parts polypropylene, 18 parts modified talc, 2.5 parts compatibilizer, 0.8 parts lubricant, and 0.7 parts antioxidant.

[0081] The method for preparing the modified talc powder includes the following steps:

[0082] S1. Add 100g of talc powder to 800mL of ethanol-water solution (ethanol to water volume ratio of 9:1), then add 8g of γ-aminopropyltrimethoxysilane, stir at 70℃ for 4h, filter, wash and dry after the reaction is complete to obtain amino-modified talc powder.

[0083] S2. Add 100g of aminated talc powder to 1L of dimethylacetamide, then add 25g of pyromellitic dianhydride, and react at a constant temperature of 50℃ for 5h. After the reaction is completed, filter, wash and dry to obtain modified talc powder.

[0084] The lubricant is erucamide, the compatibilizer is maleic anhydride-grafted polypropylene, and the antioxidant is composed of antioxidant 1098 and antioxidant 168 in a mass ratio of 2:1.

[0085] A method for preparing a polypropylene corrugated pipe composite material includes the following steps:

[0086] Weigh the raw materials according to the formula, premix the polypropylene, modified talc, compatibilizer, lubricant and antioxidant in a high-speed mixer until uniform, and then add them to a twin-screw extruder. After melt blending, extrusion and pelletizing, the polypropylene corrugated pipe composite material is obtained.

[0087] The processing temperatures of each zone of the twin-screw extruder are set as follows: Zone 1 180℃, Zone 2 190℃, Zone 3 200℃, Zone 4 210℃, Zone 5 220℃, and Die Head 215℃; the main engine speed of the twin-screw extruder is 400 rpm.

[0088] Compared to Example 1, this comparative example did not introduce castor oil into the modified talc.

[0089] Comparative Example 2

[0090] A polypropylene corrugated pipe composite material, comprising the following raw materials by weight:

[0091] 95 parts polypropylene, 18 parts modified talc, 2.5 parts compatibilizer, 0.8 parts lubricant, and 0.7 parts antioxidant.

[0092] The method for preparing the modified talc powder includes the following steps:

[0093] S1. Add 100g of talc powder to 800mL of ethanol-water solution (ethanol to water volume ratio of 9:1), then add 8g of γ-aminopropyltrimethoxysilane, stir at 70℃ for 4h, filter, wash and dry after the reaction is complete to obtain amino-modified talc powder.

[0094] S2. Add 100g of amino-modified talc powder to 1L of dimethylacetamide, then add 25g of ethylenediaminetetraacetic acid dianhydride, and react at 50℃ for 5h. After the reaction is complete, filter, wash and dry to obtain functionalized talc powder.

[0095] S3. Add 100g of functionalized talc powder to 1L of dimethylacetamide, then add 20g of castor oil and 0.15g of dibutyltin dilaurate, and react at 135℃ for 6h. After the reaction is complete, filter, wash and dry to obtain modified talc powder.

[0096] The lubricant is erucamide, the compatibilizer is maleic anhydride-grafted polypropylene, and the antioxidant is composed of antioxidant 1098 and antioxidant 168 in a mass ratio of 2:1.

[0097] A method for preparing a polypropylene corrugated pipe composite material includes the following steps:

[0098] Weigh the raw materials according to the formula, premix the polypropylene, modified talc, compatibilizer, lubricant and antioxidant in a high-speed mixer until uniform, and then add them to a twin-screw extruder. After melt blending, extrusion and pelletizing, the polypropylene corrugated pipe composite material is obtained.

[0099] The processing temperatures of each zone of the twin-screw extruder are set as follows: Zone 1 180℃, Zone 2 190℃, Zone 3 200℃, Zone 4 210℃, Zone 5 220℃, and Die Head 215℃; the main engine speed of the twin-screw extruder is 400 rpm.

[0100] Compared with Example 1, this comparative example replaces the pyromellitic dianhydride in the modified talc with ethylenediaminetetraacetic dianhydride.

[0101] Comparative Example 3

[0102] A polypropylene corrugated pipe composite material, comprising the following raw materials by weight:

[0103] 95 parts polypropylene, 18 parts modified talc, 2.5 parts compatibilizer, 0.8 parts lubricant, and 0.7 parts antioxidant.

[0104] The method for preparing the modified talc powder includes the following steps:

[0105] S1. Add 100g of talc powder to 800mL of ethanol-water solution (ethanol to water volume ratio of 9:1), then add 8g of γ-aminopropyltrimethoxysilane, stir at 70℃ for 4h, filter, wash and dry after the reaction is complete to obtain amino-modified talc powder.

[0106] S2. Mix 100g of amino-modified talc powder, 25g of pyromellitic dianhydride, and 20g of castor oil evenly to obtain modified talc powder.

[0107] The lubricant is erucamide, the compatibilizer is maleic anhydride-grafted polypropylene, and the antioxidant is composed of antioxidant 1098 and antioxidant 168 in a mass ratio of 2:1.

[0108] A method for preparing a polypropylene corrugated pipe composite material includes the following steps:

[0109] Weigh the raw materials according to the formula, premix the polypropylene, modified talc, compatibilizer, lubricant and antioxidant in a high-speed mixer until uniform, and then add them to a twin-screw extruder. After melt blending, extrusion and pelletizing, the polypropylene corrugated pipe composite material is obtained.

[0110] The processing temperatures of each zone of the twin-screw extruder are set as follows: Zone 1 180℃, Zone 2 190℃, Zone 3 200℃, Zone 4 210℃, Zone 5 220℃, and Die Head 215℃; the main engine speed of the twin-screw extruder is 400 rpm.

[0111] Compared with Example 1, the modified talc in this comparative example was prepared by physical blending of aminated talc, pyromellitic dianhydride and castor oil.

[0112] The polypropylene corrugated pipe composites prepared in Examples 1-4 and Comparative Examples 1-3 were subjected to performance tests. Tensile strength and elongation at break were tested according to GB / T 1040.2-2022 "Determination of Tensile Properties of Plastics - Part 2: Test Conditions for Molded and Extruded Plastics" using a 180mm × 10mm × 4mm specimen at a tensile speed of 50mm / min. Corrugated pipes were prepared from the polypropylene corrugated pipe composites of Examples 1-4 and Comparative Examples 1-3. The ring stiffness of the samples was tested according to the test methods disclosed in GB / T 35451.1-2017 "Polypropylene (PP) Structural Wall Piping Systems for Buried Drainage and Sewage". Notched impact strength was tested according to GB / T 1843-2008 "Determination of Impact Strength of Plastic Cantilever Beams" using an 80mm × 10mm × 4mm specimen with a remaining notch thickness of 2mm at a test temperature of 23℃. Flexural modulus was tested according to GB / T... The test was conducted according to the standard 9341-2008 "Determination of Flexural Properties of Plastics". The sample size was 80mm×10mm×4mm. The test results are shown in Table 1 below.

[0113] Table 1

[0114] Tensile strength (MPa) Elongation at break (%) <![CDATA[Ring stiffness (kN / m 2 )]]> <![CDATA[Izod impact strength (kJ / m 2 )]]> Flexural modulus (MPa) Example 1 36.7 138 15.9 21.6 2960 Example 2 35.6 142 15.2 20.9 2830 Example 3 36.1 126 15.4 21.5 2890 Example 4 36.4 135 15.8 21.1 2940 Comparative Example 1 28.5 54 16.1 11.3 3050 Comparative Example 2 30.3 147 12.9 16.5 2540 Comparative Example 3 27.6 46 9.5 10.2 2680

[0115] As can be seen from Table 1 above, the polypropylene corrugated pipe composite material provided by the present invention has good comprehensive performance and high industrial application value.

[0116] The above description is a further detailed explanation of the present invention in conjunction with specific implementation examples. It should not be considered that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept of the present invention, and all such deductions or substitutions should be considered to fall within the protection scope of the present invention.

[0117] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A polypropylene corrugated pipe composite material, characterized in that, By weight, it includes the following ingredients: 90-100 parts polypropylene, 15-20 parts modified talc, 2-3 parts compatibilizer, 0.5-1 part lubricant, and 0.5-0.8 parts antioxidant.

2. The polypropylene corrugated pipe composite material according to claim 1, characterized in that, By weight, it includes the following ingredients: 95-100 parts polypropylene, 17-20 parts modified talc, 2.5-3 parts compatibilizer, 0.7-1 part lubricant, and 0.5-0.7 parts antioxidant.

3. The polypropylene corrugated pipe composite material according to claim 1, characterized in that, The method for preparing the modified talc powder includes the following steps: S1. Add talc powder to an aqueous ethanol solution, then add γ-aminopropyltrimethoxysilane, stir and react. After the reaction is complete, filter, wash and dry to obtain amino-modified talc powder. S2. Add the aminoated talc powder to dimethylacetamide, then add pyromellitic dianhydride, and carry out a constant temperature reaction. After the reaction is completed, filter, wash and dry to obtain functionalized talc powder. S3. Functionalized talc powder is added to dimethylacetamide, followed by castor oil and dibutyltin dilaurate. The mixture is heated to react. After the reaction is complete, the mixture is filtered, washed, and dried to obtain modified talc powder.

4. The polypropylene corrugated pipe composite material according to claim 3, characterized in that, In step S1, the volume ratio of ethanol to water in the aqueous ethanol solution is 8-9:1-2, the mass ratio of talc to γ-aminopropyltrimethoxysilane is 100:6-9, and the stirring reaction is carried out at a temperature of 65-75℃ for 3-5 hours.

5. The polypropylene corrugated pipe composite material according to claim 3, characterized in that, In step S2, the mass ratio of aminated talc to pyromellitic dianhydride is 100:20-30, and the isothermal reaction is carried out at a temperature of 40-60°C for 4-6 hours.

6. The polypropylene corrugated pipe composite material according to claim 3, characterized in that, In step S3, the mass ratio of functionalized talc, castor oil, and dibutyltin dilaurate is 100:15-25:0.1-0.2, and the heating reaction temperature is 130-140℃ for 5-7 hours.

7. The polypropylene corrugated pipe composite material according to claim 1, characterized in that, The lubricant is one or more of erucamide, calcium stearate, and ethylene bis-stearamide; the compatibilizer is maleic anhydride-grafted polypropylene; and the antioxidant is composed of antioxidant 1098 and antioxidant 168 in a mass ratio of 2:

1.

8. A method for preparing a polypropylene corrugated pipe composite material as described in any one of claims 1-7, characterized in that, Includes the following steps: Weigh the raw materials according to the formula, premix the polypropylene, modified talc, compatibilizer, lubricant and antioxidant in a high-speed mixer until uniform, and then add them to a twin-screw extruder. After melt blending, extrusion and pelletizing, the polypropylene corrugated pipe composite material is obtained.

9. The preparation method according to claim 8, characterized in that, The processing temperatures of each zone of the twin-screw extruder are set as follows: Zone 1 170-190℃, Zone 2 180-200℃, Zone 3 190-210℃, Zone 4 200-220℃, Zone 5 200-220℃, and Die head 210-230℃; the main engine speed of the twin-screw extruder is 300-500 rpm.

10. A composite polypropylene corrugated pipe prepared from the polypropylene corrugated pipe composite material as described in any one of claims 1-7.