Continuous fiber-reinforced bio-based copolyamide pipe and method of making and use thereof

Abstract

The application discloses a kind of continuous fiber reinforced bio-based copolyamide pipe and its preparation method and application.The continuous fiber reinforced bio-based copolyamide pipe includes bio-based copolyamide resin composition and continuous fiber, and the mass fraction ratio of bio-based copolyamide resin composition and continuous fiber is (10:90) to (50:50);Wherein, the bio-based copolyamide resin composition includes: bio-based copolyamide resin 60-90 parts, polyolefin 8-25 parts, compatible agent 3-12 parts, antioxidant 0.1-1 part, coupling agent 0.1-0.8 part, release agent 0.1-1 part.The pipe prepared by the application has low water absorption, good heat resistance, excellent mechanical properties, high temperature internal pressure resistance and other characteristics, and is more widely used.

Description

Technical Field

[0001] This invention relates to a continuous fiber-reinforced bio-based copolyamide pipe, its preparation method, and its application. Background Technology

[0002] As humanity continues to expand its research scope, pipeline engineering, as a fundamental construction project, is experiencing a surge in the demand for and demand for high-performance pipelines. Applications such as crude oil transportation, fly ash transportation in thermal power plants, and high-abrasion slurry transportation in mines require ultra-high wear resistance, corrosion resistance, and high-pressure resistance pipelines. Pipes made of single materials such as cast iron, steel, prestressed reinforced concrete, polyethylene, polypropylene, and rigid polyvinyl chloride cannot meet the requirements of these harsh environments. Therefore, composite pipes have become a research hotspot in recent years.

[0003] The preparation of composite pipes using fiber-reinforced thermoplastic materials is a currently popular research direction. The resulting pipes have a series of unique advantages, such as light weight, high strength, low cost, corrosion resistance, and environmental friendliness, and have great application prospects in municipal, water conservancy, coal, chemical, oil and gas and other fields.

[0004] Most existing fiber-reinforced thermoplastic spiral wound pipes use polyethylene, polypropylene, or polyvinyl chloride as the resin matrix. Although their performance is improved compared to traditional pipes, they can only be used to transport liquids or gases at around 100°C. Nylon plastic is a long-established and widely used general-purpose engineering plastic, with PA6 and PA66 being the most widely researched and applied. However, the material is prone to moisture absorption, which reduces its mechanical properties and limits its service life and application areas. In addition, the high-performance PA6 and PA66 raw materials are imported, which undoubtedly increases production and processing costs.

[0005] Therefore, there is an urgent need in this field for a fiber-reinforced polyamide pipe with low water absorption, good heat resistance, and good mechanical properties, as well as a method for its preparation. Summary of the Invention

[0006] This invention addresses the problems of poor mechanical properties and heat resistance in existing fiber-reinforced thermoplastic polyolefin pipes, and the high manufacturing cost and high water absorption of nylon plastics, which limit their application areas. It provides a continuous fiber-reinforced bio-based copolyamide pipe, its preparation method, and its applications. The preparation method of this invention is simple, feasible, low-cost, and highly efficient, with good impregnation effects. The resulting continuous fiber-reinforced bio-based copolyamide pipe exhibits excellent comprehensive performance, including good heat resistance, low water absorption, good mechanical properties, and is recyclable and reusable.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] The first aspect of the present invention provides a continuous fiber reinforced bio-based copolyamide pipe, comprising a bio-based copolyamide resin composition and continuous fibers, wherein the mass fraction ratio of the bio-based copolyamide resin composition to the continuous fibers is (10:90)-(50:50).

[0009] The bio-based copolyamide resin composition comprises: 60-90 parts of bio-based copolyamide resin, 8-25 parts of polyolefin, 3-12 parts of compatibilizer, 0.1-1 parts of antioxidant, 0.1-0.8 parts of coupling agent, and 0.1-1 parts of release agent.

[0010] In some specific embodiments, the bio-based copolyamide resin contains the following structural units (Ⅰ), (Ⅱ), and (Ⅲ).

[0011]

[0012] The molar ratio of structural unit (Ⅰ) to structural unit (Ⅱ) is 1:(0.1-0.9);

[0013] The molar ratio of structural unit (Ⅰ) to structural unit (Ⅲ) is 1:(0.1-0.9);

[0014] The molar ratio of structural unit (II) to structural unit (III) is 1:(0.1-1.5);

[0015] The structural units (Ⅰ), (Ⅱ) and (Ⅲ) are connected by amide bonds.

[0016] In some specific embodiments, the molar ratio of adipic acid to terephthalic acid can be 1:(0.35-0.55), for example 1:0.45; or 1:(0.55-0.85), for example 1:0.72; or 1:(0.85-1.2), for example 1:1.05.

[0017] In some specific embodiments, the relative viscosity of the bio-based copolyamide resin is 2.0–3.2. The relative viscosity is determined using the Ubbelohde viscometer method with concentrated sulfuric acid (96% concentration).

[0018] In some specific embodiments, the number-average molecular weight of the bio-based copolyamide resin is 20,000 to 70,000, and more specifically 30,000 to 60,000.

[0019] In some specific embodiments, the water content of the bio-based copolyamide resin is 500–2000 ppm. The water content can be reduced by drying.

[0020] In some specific embodiments, the melting point of the bio-based copolyamide resin is 260-330°C, and further 270-300°C.

[0021] In some specific embodiments, the bio-based copolyamide resin is formed from pentanediamine and dicarboxylic acid, wherein the molar ratio of pentanediamine to dicarboxylic acid is (1-1.05):1, for example 1.05:1.

[0022] In some specific embodiments, the preparation method of the bio-based copolyamide resin includes the following steps: preparing a polyamide salt solution by pentanediamine, dicarboxylic acid and water, and heating and polymerizing the polyamide salt solution to obtain the bio-based copolyamide resin.

[0023] In some specific embodiments, the dicarboxylic acid contains 40-90 mol% adipic acid and 10-60 mol% terephthalic acid or a derivative thereof, wherein the percentages are molar percentages.

[0024] In some specific embodiments, the preparation method of the bio-based copolyamide resin includes the following steps: (1) Under a nitrogen or inert gas atmosphere, water, pentanediamine, terephthalic acid or its derivatives, and adipic acid are mixed to prepare a polyamide salt aqueous solution with a concentration of 30-75wt%; (2) The polyamide salt aqueous solution is transferred to a polymerization apparatus (e.g., a polymerization kettle), heated under a nitrogen or inert gas atmosphere to raise the temperature of the reaction system to 230-310℃ and the pressure to 0.7-2.5MPa, and maintained for 60-180 minutes; then, the pressure is reduced to atmospheric pressure within 30-120 minutes by venting, while the temperature is raised to 260-340℃; vacuum is applied to reduce the pressure to -(0.02-0.08)MPa and maintained for 30-120 minutes to obtain a melt; (3) The melt is stretched and granulated to obtain the bio-based copolyamide resin PA56 / 5T.

[0025] In this invention, the content of the bio-based copolyamide resin is preferably 68-83 parts, for example 68 parts, 70 parts, 71 parts, 75 parts, 78 parts, 80 parts, or 83 parts.

[0026] In some specific embodiments, the polyolefin is selected from one or more of polyethylene, polypropylene, and polybutene; for example, polyethylene PE100S can be purchased from Jilin Petrochemical, and polypropylene PP212E can be purchased from Borealis.

[0027] In this invention, the content of the polyolefin is preferably 10-23 parts, for example 10 parts, 14 parts, 16 parts, 20 parts, or 23 parts.

[0028] In some specific embodiments, the compatibilizer may be selected from one or more of polyolefin-grafted maleic anhydride compatibilizers, polyolefin-grafted methyl ester-acrylate compatibilizers, and rubber elastomer-grafted maleic anhydride compatibilizers. The polyolefin-grafted maleic anhydride compatibilizer may be conventional in the art, such as PP-g-MAH or POE-g-MAH. The polyolefin-grafted methyl ester-acrylate compatibilizer may be conventional in the art, such as POE-g-GMA. The rubber elastomer-grafted maleic anhydride compatibilizer may be conventional in the art, such as EPDM-g-MAH.

[0029] Preferably, the compatibilizer is selected from one or more of PP-g-MAH, POE-g-MAH, POE-g-GMA, or EPDM-g-MAH.

[0030] In this invention, the content of the compatibilizer is preferably 4-9 parts, for example 5.8 parts, 7 parts, 7.6 parts, 8 parts, or 8.2 parts.

[0031] In some specific embodiments, the antioxidant may be selected from one or more of hindered phenolic antioxidants, hindered amine antioxidants, and phosphite antioxidants; preferably, a combination of hindered amine antioxidants and phosphite antioxidants. The hindered phenolic antioxidant may be conventional in the art, such as antioxidant 1010. The hindered amine antioxidant may be conventional in the art, such as antioxidant 1098 (CAS 23128-74-7). The phosphite antioxidant may be conventional in the art, such as antioxidant 168 (CAS 31570-04-4) and antioxidant S9228.

[0032] Preferably, the antioxidant is selected from one or more of antioxidant 168, antioxidant 1098, antioxidant 1010 and antioxidant S9228.

[0033] In this invention, the content of the antioxidant is preferably 0.2-1.0 parts, for example 0.3 parts, 0.5 parts, 0.6 parts, 0.7 parts, or 0.8 parts.

[0034] In some specific embodiments, the coupling agent may be selected from one or more of silane coupling agents, carbonate coupling agents, and aluminate coupling agents; preferably, a silane coupling agent, such as coupling agent KH550, coupling agent KH560, or coupling agent KH570. The coupling agent is generally selected based on the composition and surface structure of the fiber used and the melting point of the bio-based polyamide resin.

[0035] In this invention, the amount of the coupling agent is preferably 0.3-0.8 parts, for example 0.4 parts, 0.5 parts, or 0.7 parts.

[0036] In some specific embodiments, the release agent is selected from oleamide and / or erucamide.

[0037] In this invention, the content of the release agent is preferably 0.1-0.5 parts, for example 0.2 parts, 0.3 parts, or 0.4 parts.

[0038] In this invention, the continuous fiber can be of a type conventional in the art, such as one or more of carbon fiber, glass fiber, silicon carbide fiber, basalt fiber, natural flax fiber, aramid fiber, semi-aromatic polyamide fiber, or polyolefin fiber. Preferably, the continuous fiber can be a continuous long fiber.

[0039] Preferably, the continuous fiber is a continuous long glass fiber with a single filament diameter of 8-15 μm, and more preferably 8-10 μm. Preferably, the linear density of the continuous long glass fiber is 1200-4800 Tex, for example, 1200 Tex, 2400 Tex, or 3600 Tex. The continuous long glass fiber is, for example, a 1200 Tex continuous long glass fiber purchased from Owens Corning (OC) or a 2400 Tex continuous long glass fiber purchased from Jushi.

[0040] Preferably, the continuous fiber is a continuous long carbon fiber, such as polyacrylonitrile carbon fiber; the number of monofilaments of the continuous long carbon fiber can be 10K-60K, for example 12K, 24K, 36K. The diameter of the monofilaments of the continuous long carbon fiber can be 5-10μm. The continuous long carbon fiber is, for example, Toray T700 with a specification of 24K, or Guangwei Composites continuous long carbon fiber 700S with a specification of 12K or 24K.

[0041] In this invention, the bio-based copolyamide resin composition can be prepared using conventional methods in the art, generally involving mixing the above components in a high-speed mixer.

[0042] A second aspect of the present invention provides a method for preparing the above-mentioned continuous fiber reinforced bio-based copolyamide pipe, comprising the following steps:

[0043] S1. The bio-based copolyamide resin composition is extruded, and the melt enters the impregnation die;

[0044] S2. The continuous fiber is introduced into the impregnation die head, and the melt and the fiber are impregnated.

[0045] S3. The impregnated fibers are molded, cooled, drawn and wound to obtain a prepreg tape;

[0046] S4. Wrap the prepreg tape around the mandrel, roll it, cool it, demold it, and cut it into sections to obtain the final product.

[0047] In this invention, the mass fraction ratio of the bio-based copolyamide resin composition to the continuous fiber is controlled to be (10:90)-(50:50) by adjusting the extrusion speed and the winding speed.

[0048] Preferably, in step S1, the extrusion can be performed using a conventional twin-screw extruder or a single-screw extruder, with a twin-screw extruder being more preferred. The length-to-diameter ratio of the twin-screw extruder is preferably 36:1.

[0049] Preferably, in step S1, the extrusion temperature can be 170-340°C.

[0050] Preferably, the twin-screw extruder adopts an eight-zone heating mode, with the temperatures of zones one through eight being 205-260℃, 265-305℃, 275-325℃, 275-325℃, 275-325℃, 275-325℃, 275-325℃, and 275-325℃, respectively.

[0051] Preferably, in step S1, the extrusion speed, expressed in screw rotation speed, is 200-600 rpm, for example, 300 rpm or 400 rpm.

[0052] Preferably, in step S1, the post-extrusion process further includes a filtration step. The filtration can be performed using a melt filter conventional in the art. Preferably, when using a twin-screw extruder, the temperature of the melt filter is within 0-15°C above or below the temperature of the eight zones of the twin-screw extruder, for example, 275°C, 285°C, or 315°C.

[0053] In step S1, the impregnation die head can be a die head conventional in the art. Preferably, the width of the impregnation die head is 100-650 mm.

[0054] Preferably, in step S1, the temperature of the impregnation die is 240-330°C, more preferably 290-330°C. More preferably, when a twin-screw extruder is used, the temperature of the impregnation die is within 0-15°C above or below the temperature of the eight zones of the twin-screw extruder, for example, 290°C, 295°C, 315°C, or 330°C.

[0055] In step S2, when the fiber is a continuous long fiber, the introduction generally includes the following process: the continuous long fiber is unwound from the yarn rack by a tension controller, passes through a yarn separating frame, enters a yarn spreading system to fully spread each filament bundle, then enters a yarn drying device for preheating, and then enters an impregnation die; wherein, when the fiber is a continuous long glass fiber, the temperature of the yarn drying device is preferably 70-90℃, for example 80℃ or 85℃; when the fiber is a continuous long carbon fiber, the temperature of the yarn drying device is preferably 70-400℃, for example 80℃, 100℃, 200℃, 250℃, 300℃, or 350℃.

[0056] In step S2, the continuous fiber is as described above.

[0057] In step S3, the molding and cooling can be performed using conventional roller presses, preferably four-roll presses. The temperature of the internal circulating water in the four-roll press can be 15-40°C, for example, 20°C.

[0058] In step S3, the traction can be performed using a conventional traction device in the art, where further cooling and trimming are carried out. The traction speed can be 5-20 m / min, for example, 8 m / min or 5 m / min.

[0059] In step S3, the winding can be performed using conventional winding equipment in the art, preferably an automatic winding machine. The winding speed can be 3-15 m / min, for example, 8 m / min or 3 m / min.

[0060] In this invention, preferably, the prepreg tape refers to a strip-shaped prepreg made by impregnating resin with parallel continuous fibers.

[0061] In this invention, preferably, the thickness of the prepreg tape is 0.15-0.4 mm, for example 0.25 mm or 0.33 mm.

[0062] In this invention, preferably, in step S4, the winding temperature is 280-350°C, and the temperature is obtained by hot air heating or infrared heating.

[0063] In this invention, preferably, in step S4, the winding speed is 1-30 m / min, more preferably 5-20 m / min.

[0064] In this invention, preferably, in step S4, the winding angle is between 30° and 75°, and more preferably within the range of 40° and 60°.

[0065] In this invention, the mandrel is preferably circular. The rolling process uses steel rollers, the number and diameter of which are determined by those skilled in the art based on actual conditions. Cooling is achieved through water cooling.

[0066] The third aspect of this invention provides an application of the above-mentioned continuous fiber reinforced bio-based copolyamide pipe in the fields of building water supply and drainage pipes, heating pipes, gas pipes, electrical conduits, industrial pipes, submarine pipelines, and other facilities.

[0067] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of the present invention. All reagents and raw materials used in the present invention are commercially available.

[0068] The positive and progressive effects of this invention are as follows:

[0069] 1. This invention uses bio-based copolyamide as raw material:

[0070] (1) The monomer pentanediamine in the raw material is prepared by bio-fermentation. It has a high bio-based content, which can effectively reduce the use of fossil raw materials and thus reduce carbon emissions;

[0071] (2) The bio-based copolyamide material of the present invention has low viscosity and good fluidity in the molten state, and good wettability to fibers;

[0072] (3) It expands the range of materials for unidirectional belts and reduces costs.

[0073] 2. The pipe material described in this invention has a high fiber content, ranging from 50% to 90%; and features low water absorption, good heat resistance, excellent mechanical properties, high temperature resistance to internal pressure, and recyclability.

[0074] 3. The preparation method of the present invention is simple and quick, can realize continuous production of pipes, and has low cost and high practicality. Detailed Implementation

[0075] The present invention is further illustrated below by way of embodiments, but the invention is not limited to the scope of the embodiments described herein. Experimental methods in the following embodiments that do not specify specific conditions were performed according to conventional methods and conditions, or as selected according to the product instructions.

[0076] Unless otherwise specified, all raw materials used in the following examples and comparative examples are commercially available:

[0077] Pentylenediamine was purchased from Kaisai (Jinxiang) Biomaterials Co., Ltd.; polyethylene PE100S was purchased from Jilin Petrochemical; polypropylene PP212E was purchased from Borealis; antioxidants were purchased from BASF Group, Germany; compatibilizers were purchased from Shanghai Jiayirong Polymer Co., Ltd.; coupling agents were purchased from Hangzhou Jessica Chemical Co., Ltd.; release agents were purchased from Shanghai Kaiyin Chemical Co., Ltd.; continuous long glass fibers were purchased from Owens Corning (OC), with a specification of 1200Tex; continuous long carbon fibers were Toray T700, with a specification of 24K.

[0078] Bio-based copolyamide A: The preparation method includes the following steps: (1) Under a nitrogen atmosphere, water, pentanediamine, and dicarboxylic acid (amic acid and terephthalic acid in a molar ratio of 1:1.05) are mixed to prepare a polyamide salt aqueous solution with a concentration of 65wt%; the molar ratio of pentanediamine and dicarboxylic acid is 1.05:1; (2) The polyamide salt aqueous solution is transferred to a polymerization reactor, heated under a nitrogen atmosphere, the temperature inside the reactor is raised to 290℃, the pressure inside the polymerization device is raised to 1.6MPa, and maintained for 110 minutes; then the pressure is reduced to atmospheric pressure within 85 minutes, while the temperature inside the polymerization device is raised to 300℃; vacuum is drawn to reduce the pressure to -0.05MPa, maintained for 60 minutes, and a melt is obtained, which is then stretched and granulated to obtain bio-based polyamide resin PA56 / 5T-A (relative viscosity 2.24, number average molecular weight 30,000, melting point 300℃, water content after drying 800ppm).

[0079] Bio-based copolyamide B: The preparation method includes the following steps: (1) Under a nitrogen atmosphere, water, pentanediamine, and dicarboxylic acid (amic acid and terephthalic acid in a molar ratio of 1:0.72) are mixed to prepare a polyamide salt aqueous solution with a concentration of 65wt%; the molar ratio of pentanediamine and dicarboxylic acid is 1.05:1; (2) The polyamide salt aqueous solution is transferred to a polymerization reactor, heated under a nitrogen atmosphere, the temperature inside the reactor is raised to 290℃, the pressure inside the polymerization device is raised to 1.6MPa, and maintained for 110 minutes; then the pressure is reduced to atmospheric pressure within 85 minutes, while the temperature inside the polymerization device is raised to 300℃; vacuum is drawn to reduce the pressure to -0.05MPa, maintained for 60 minutes, and a melt is obtained, which is then stretched and granulated to obtain bio-based polyamide resin PA56 / 5T-B (relative viscosity 2.31, number average molecular weight 40,000, melting point 290℃, and water content 800ppm after drying).

[0080] Bio-based polyamide C: The preparation method includes the following steps: (1) Under a nitrogen atmosphere, water, pentanediamine, and dicarboxylic acid (amic acid and terephthalic acid in a molar ratio of 1:0.45) are mixed to prepare a polyamide salt aqueous solution with a concentration of 65wt%; the molar ratio of pentanediamine and dicarboxylic acid is 1.05:1; (2) The polyamide salt aqueous solution is transferred to a polymerization reactor, heated under a nitrogen atmosphere, the temperature inside the reactor is raised to 290℃, the pressure inside the polymerization device is raised to 1.6MPa, and maintained for 110 minutes; then the pressure is reduced to atmospheric pressure within 85 minutes, while the temperature inside the polymerization device is raised to 300℃; vacuum is drawn to reduce the pressure to -0.05MPa, maintained for 60 minutes, and a melt is obtained, which is then stretched and granulated to obtain bio-based polyamide resin PA56 / 5T-C (relative viscosity 2.45, number average molecular weight 60,000, melting point 270℃, and water content 800ppm after drying).

[0081] Example 1

[0082] 1. Preparation of bio-based copolyamide resin composition:

[0083] Bio-based copolyamide A: 68 parts, polyethylene PE100S: 23 parts, antioxidant 1098: 0.8 parts, compatibilizer PE-g-MAH: 7.6 parts, coupling agent KH560: 0.4 parts, release agent erucamide: 0.2 parts. The above components are added to a high-speed mixer and mixed to obtain a bio-based copolyamide resin composition.

[0084] 2. Preparation of continuous fiber-reinforced bio-based copolyamide pipes:

[0085] S1. The bio-based copolyamide resin composition obtained above is extruded using a twin-screw extruder. The extruded melt is filtered through a melt filter and enters the impregnation die. The twin-screw extruder is an eight-zone heating system, with zone 1 to zone 8 (feeding to the die head) temperatures of 250℃, 275℃, 300℃, 310℃, 310℃, 310℃, 310℃, and 300℃ respectively. The screw speed is 400 r / min. The length-to-diameter ratio of the twin-screw extruder is 36:1. The temperature of the melt filter is 300℃. The die head temperature is 300℃.

[0086] S2. The continuous long glass fiber is unwound from the yarn rack by the tension controller, passes through the yarn separating frame, and enters the yarn spreading system to fully spread each filament bundle. Then it enters the yarn drying device for preheating. The temperature of the yarn drying device is set at 85℃. Then it enters the impregnation die head, where the continuous long glass fiber is impregnated with the melt.

[0087] S3. The impregnated continuous long glass fibers are molded and cooled using a four-roll mill, with the circulating water temperature inside the four-roll mill set to 20℃. They then enter a traction device for further cooling and edge trimming, with a traction speed of 15m / min. Finally, they are wound into a roll in an automatic winding machine at a winding speed of 15m / min, yielding a unidirectional prepreg tape with a thickness of 0.22mm. During the preparation process, the screw speed of the twin-screw extruder and the winding speed of the automatic winding machine are controlled to ensure that the mass fraction ratio of the bio-based copolyamide resin composition to the continuous long glass fibers is 35:65.

[0088] S4. The unidirectional prepreg tape is wound on a circular winding mandrel at a winding angle of 60°. The winding temperature is 320°C (obtained by hot air heating or infrared heating), and the winding speed is 13m / min. After being rolled, it is cooled with water, demolded, and cut into sections to obtain the final product.

[0089] Example 2

[0090] 1. Preparation of bio-based copolyamide resin composition:

[0091] Bio-based copolyamide B: 83 parts, polypropylene PP212E: 10 parts, antioxidant 168: 0.5 parts, compatibilizer PP-g-MAH: 5.8 parts, coupling agent KH560: 0.5 parts, release agent erucamide: 0.2 parts. The above components are added to a high-speed mixer and mixed to obtain a bio-based copolyamide resin composition.

[0092] 2. Preparation of continuous fiber-reinforced bio-based copolyamide pipes:

[0093] S1. The bio-based copolyamide resin composition obtained above is extruded using a twin-screw extruder. The extruded melt is filtered through a melt filter and enters the impregnation die. The twin-screw extruder is an eight-zone heating mode, with zone 1 to zone 8 (feeding to the die head) temperatures of 250℃, 275℃, 300℃, 310℃, 310℃, 310℃, 310℃, and 300℃ respectively. The screw speed is 450 r / min. The length-to-diameter ratio of the twin-screw extruder is 36:1. The temperature of the melt filter is 300℃. The die head temperature is 300℃.

[0094] S2. The continuous long glass fiber is unwound from the yarn rack by the tension controller, passes through the yarn separating frame, and enters the yarn spreading system to fully spread each filament bundle. Then it enters the yarn drying device for preheating. The temperature of the yarn drying device is set at 85℃. Then it enters the impregnation die head, where the continuous long glass fiber is impregnated with the melt.

[0095] S3. The impregnated continuous long glass fibers are molded and cooled using a four-roll mill, with the circulating water temperature inside the mill set to 20℃. They then enter a traction device for further cooling and edge trimming at a traction speed of 9 m / min. Finally, they are wound into a roll using an automatic winding machine at a winding speed of 9 m / min, resulting in a unidirectional prepreg tape with a thickness of 0.20 mm. During the preparation process, the screw speed of the twin-screw extruder and the winding speed of the automatic winding machine are controlled to ensure that the mass fraction ratio of the bio-based copolyamide resin composition to the continuous long glass fibers is 25:75.

[0096] S4. The unidirectional prepreg tape is wound on a circular winding mandrel at a winding angle of 50°. The winding temperature is 305°C (obtained by hot air heating or infrared heating), and the winding speed is 12m / min. After being rolled, it is cooled with water, demolded, and cut into sections to obtain the final product.

[0097] Example 3

[0098] 1. Preparation of bio-based copolyamide resin composition:

[0099] Bio-based copolyamide C: 71 parts, polyethylene PE100S: 20 parts, antioxidant 1098: 0.5 parts, compatibilizer POE-g-MAH: 8 parts, coupling agent KH550: 0.5 parts, release agent erucamide: 0.2 parts. The above components are added to a high-speed mixer and mixed to obtain a bio-based copolyamide resin composition.

[0100] 2. Preparation of continuous fiber-reinforced bio-based copolyamide pipes:

[0101] S1. The bio-based copolyamide resin composition obtained above is extruded using a twin-screw extruder. The extruded melt is filtered through a melt filter and enters the impregnation die. The twin-screw extruder is an eight-zone heating mode, with zone 1 to zone 8 (feeding to the die head) temperatures of 250℃, 275℃, 300℃, 310℃, 310℃, 310℃, 310℃, and 300℃ respectively. The screw speed is 350 r / min. The length-to-diameter ratio of the twin-screw extruder is 36:1. The temperature of the melt filter is 310℃. The die head temperature is 310℃.

[0102] S2. The continuous long glass fiber is unwound from the yarn rack by the tension controller, passes through the yarn separating frame, and enters the yarn spreading system to fully spread each filament bundle. Then it enters the yarn drying device for preheating. The temperature of the yarn drying device is set at 85℃. Then it enters the impregnation die head, where the continuous long glass fiber is impregnated with the melt.

[0103] S3. The impregnated continuous long glass fibers are molded and cooled using a four-roll mill, with the circulating water temperature inside the mill set to 20℃. They then enter a traction device for further cooling and edge trimming at a traction speed of 15 m / min. Finally, they are wound into a roll in an automatic winding machine at a winding speed of 15 m / min, yielding a unidirectional prepreg tape with a thickness of 0.20 mm. During the preparation process, the screw speed of the twin-screw extruder and the winding speed of the automatic winding machine are controlled to ensure that the mass fraction ratio of the bio-based copolyamide resin composition to the continuous long glass fibers is 30:70.

[0104] S4. The unidirectional prepreg tape is wound on a circular winding mandrel at a winding angle of 45°. The winding temperature is 300°C (obtained by hot air heating or infrared heating), and the winding speed is 15m / min. After being rolled, it is cooled with water, demolded, and cut into sections to obtain the final product.

[0105] Example 4

[0106] 1. Preparation of bio-based copolyamide resin composition:

[0107] Bio-based copolyamide A: 70 parts, polypropylene PP212E: 20 parts, antioxidant 168: 0.7 parts, compatibilizer POE-g-MAH: 8.2 parts, coupling agent KH550: 0.7 parts, release agent erucamide: 0.2 parts. The above components are added to a high-speed mixer and mixed to obtain a bio-based copolyamide resin composition.

[0108] 2. Preparation of continuous fiber-reinforced bio-based copolyamide pipes:

[0109] S1. The bio-based copolyamide resin composition obtained above is extruded using a twin-screw extruder. The extruded melt is filtered through a melt filter and enters the impregnation die. The twin-screw extruder is an eight-zone heating mode, with zone 1 to zone 8 (feeding to the die head) temperatures of 250℃, 275℃, 300℃, 310℃, 310℃, 310℃, 310℃, and 300℃ respectively. The screw speed is 450 r / min. The length-to-diameter ratio of the twin-screw extruder is 36:1. The temperature of the melt filter is 300℃. The die head temperature is 300℃.

[0110] S2. The continuous long glass fiber is unwound from the yarn rack by the tension controller, passes through the yarn separating frame, and enters the yarn spreading system to fully spread each filament bundle. Then it enters the yarn drying device for preheating. The temperature of the yarn drying device is set at 85℃. Then it enters the impregnation die head, where the continuous long glass fiber is impregnated with the melt.

[0111] S3. The impregnated continuous long glass fibers are molded and cooled using a four-roll mill, with the circulating water temperature inside the mill set to 20℃. They then enter a traction device for further cooling and edge trimming at a traction speed of 12 m / min. Finally, they are wound into a roll in an automatic winding machine at a winding speed of 12 m / min, yielding a unidirectional prepreg tape with a thickness of 0.24 mm. During the preparation process, the screw speed of the twin-screw extruder and the winding speed of the automatic winding machine are controlled to ensure that the mass fraction ratio of the bio-based copolyamide resin composition to the continuous long glass fibers is 25:75.

[0112] S4. The unidirectional prepreg tape is wound on a circular winding mandrel at a winding angle of 50°. The winding temperature is 320°C (obtained by hot air heating or infrared heating), and the winding speed is 10m / min. After being rolled, it is cooled with water, demolded, and cut into sections to obtain the final product.

[0113] Example 5

[0114] 1. Preparation of bio-based copolyamide resin composition:

[0115] Bio-based copolyamide B: 75 parts, polyethylene PE100S: 16 parts, antioxidant 1098: 0.6 parts, compatibilizer POE-g-MAH: 8 parts, coupling agent KH550: 0.4 parts, mold release agent erucamide: 0.3 parts. The above components are added to a high-speed mixer and mixed to obtain a bio-based copolyamide resin composition.

[0116] 2. Preparation of continuous fiber-reinforced bio-based copolyamide pipes:

[0117] S1. The bio-based copolyamide resin composition obtained above is extruded using a twin-screw extruder. The extruded melt is filtered through a melt filter and enters the impregnation die. The twin-screw extruder is an eight-zone heating system, with zone 1 to zone 8 (feeding to the die head) temperatures of 250℃, 275℃, 300℃, 310℃, 310℃, 310℃, 310℃, and 300℃ respectively. The screw speed is 400 r / min. The length-to-diameter ratio of the twin-screw extruder is 36:1. The temperature of the melt filter is 300℃. The die head temperature is 300℃.

[0118] S2. The continuous long glass fiber is unwound from the yarn rack by the tension controller, passes through the yarn separating frame, and enters the yarn spreading system to fully spread each filament bundle. Then it enters the yarn drying device for preheating. The temperature of the yarn drying device is set at 85℃. Then it enters the impregnation die head, where the continuous long glass fiber is impregnated with the melt.

[0119] S3. The impregnated continuous long glass fibers are molded and cooled using a four-roll mill, with the circulating water temperature inside the mill set to 20℃. They then enter a traction device for further cooling and edge trimming at a traction speed of 15 m / min. Finally, they are wound into a roll using an automatic winding machine at a winding speed of 15 m / min, yielding a unidirectional prepreg tape with a thickness of 0.23 mm. During the preparation process, the screw speed of the twin-screw extruder and the winding speed of the automatic winding machine are controlled to ensure that the mass fraction ratio of the bio-based copolyamide resin composition to the continuous long glass fibers is 35:65.

[0120] S4. The unidirectional prepreg tape is wound on a circular winding mandrel at a winding angle of 45°. The winding temperature is 305°C (obtained by hot air heating or infrared heating), and the winding speed is 15m / min. After being rolled, it is cooled with water, demolded, and cut into sections to obtain the final product.

[0121] Example 6

[0122] 1. Preparation of bio-based copolyamide resin composition:

[0123] Bio-based copolyamide C: 78 parts, polypropylene PP212E: 14 parts, antioxidant 168: 0.3 parts, compatibilizer PE-g-MAH: 7 parts, coupling agent KH560: 0.5 parts, release agent erucamide: 0.2 parts. The above components are added to a high-speed mixer and mixed to obtain a bio-based copolyamide resin composition.

[0124] 2. Preparation of continuous fiber-reinforced bio-based copolyamide pipes:

[0125] S1. The bio-based copolyamide resin composition obtained above is extruded using a twin-screw extruder. The extruded melt is filtered through a melt filter and enters the impregnation die. The twin-screw extruder is an eight-zone heating system, with zone 1 to zone 8 (feeding to the die head) temperatures of 250℃, 275℃, 300℃, 310℃, 310℃, 310℃, 310℃, and 300℃ respectively. The screw speed is 400 r / min. The length-to-diameter ratio of the twin-screw extruder is 36:1. The temperature of the melt filter is 300℃. The die head temperature is 300℃.

[0126] S2. The continuous long glass fiber is unwound from the yarn rack by the tension controller, passes through the yarn separating frame, and enters the yarn spreading system to fully spread each filament bundle. Then it enters the yarn drying device for preheating. The temperature of the yarn drying device is set at 85℃. Then it enters the impregnation die head, where the continuous long glass fiber is impregnated with the melt.

[0127] S3. The impregnated continuous long glass fibers are molded and cooled using a four-roll mill, with the circulating water temperature inside the mill set to 20℃. They then enter a traction device for further cooling and edge trimming at a traction speed of 10m / min. Finally, they are wound into a roll in an automatic winding machine at a winding speed of 10m / min, yielding a unidirectional prepreg tape with a thickness of 0.18mm. During the preparation process, the screw speed of the twin-screw extruder and the winding speed of the automatic winding machine are controlled to ensure that the mass fraction ratio of the bio-based copolyamide resin composition to the continuous long glass fibers is 22:78.

[0128] S4. The unidirectional prepreg tape is wound on a circular winding mandrel at a winding angle of 45°. The winding temperature is 300°C (obtained by hot air heating or infrared heating), and the winding speed is 10m / min. After being rolled, it is cooled with water, demolded, and cut into sections to obtain the final product.

[0129] Example 7

[0130] The procedure was carried out in the same manner as in Example 1, except that bio-based copolyamide B was used, and all other conditions were the same as in Example 1.

[0131] Example 8

[0132] The procedure was carried out in the same manner as in Example 1, except that bio-based copolyamide C was used, and all other conditions were the same as in Example 1.

[0133] Example 9

[0134] The process was carried out in the same manner as in Example 1, except that continuous long carbon fibers were used when preparing the continuous fiber reinforced bio-based copolyamide pipe.

[0135] Example 10

[0136] The process was carried out in the same manner as in Example 2, except that continuous long carbon fibers were used when preparing the continuous fiber reinforced bio-based copolyamide pipe.

[0137] Example 11

[0138] The process was carried out in the same manner as in Example 3, except that continuous long carbon fibers were used when preparing the continuous fiber reinforced bio-based copolyamide pipe.

[0139] Comparative Example 1

[0140] The procedure is the same as in Example 1, except that:

[0141] 1. Preparation of bio-based copolyamide resin composition:

[0142] Bio-based copolyamide A: 45 parts, polyethylene PE100S: 46 parts, antioxidant 1098: 0.5 parts, compatibilizer PE-g-MAH: 8 parts, coupling agent KH560: 0.5 parts, release agent erucamide: 0.2 parts. Other conditions are the same as in Example 1.

[0143] Comparative Example 2

[0144] The procedure was performed in the same manner as Comparative Example 1, with the following difference:

[0145] 2. Preparation of continuous fiber-reinforced bio-based copolyamide pipes:

[0146] In S2, continuous long glass fibers are replaced with continuous long carbon fibers. Other conditions are the same as in Example 1.

[0147] Comparative Example 3

[0148] The procedure is the same as in Example 1, except that:

[0149] 1. Preparation of bio-based copolyamide resin composition:

[0150] Replace the bio-based copolyamide A with polyamide PA6 (purchased from Xinhui Meda Company, viscosity 2.3, melting point 223℃).

[0151] 2. Preparation of continuous fiber-reinforced bio-based copolyamide pipes:

[0152] The twin-screw extruder uses an eight-zone heating mode, with zone 1 to zone 8 (from feed to die head) temperatures of 230℃, 250℃, 270℃, 275℃, 275℃, 275℃, 275℃, and 260℃ respectively; the screw speed is 300 r / min; the melt filter temperature is 250℃; and the die head temperature is 250℃. Other conditions are the same as in Example 1.

[0153] Comparative Example 4

[0154] The procedure was carried out in the same manner as in Comparative Example 3, except that continuous long glass fibers were replaced with continuous long carbon fibers.

[0155] Comparative Example 5

[0156] The procedure is the same as in Example 1, except that:

[0157] 1. Preparation of bio-based copolyamide resin composition:

[0158] Replace the bio-based copolyamide A with polyamide PA66 (purchased from DuPont, viscosity 2.6, melting point 255℃).

[0159] 2. Preparation of continuous fiber-reinforced bio-based copolyamide pipes:

[0160] The twin-screw extruder uses an eight-zone heating mode, with zone 1 to zone 8 (from feed to die head) temperatures of 240℃, 270℃, 280℃, 285℃, 285℃, 285℃, 285℃, and 280℃ respectively; the screw speed is 400 r / min; the melt filter temperature is 270℃; and the die head temperature is 270℃. Other conditions are the same as in Example 1.

[0161] Comparative Example 6

[0162] The procedure was carried out in the same manner as in Comparative Example 5, except that continuous long glass fibers were replaced with continuous long carbon fibers.

[0163] The continuous fiber-reinforced bio-based copolyamide pipes of Examples 1-11 and Comparative Examples 1-6 were subjected to performance tests according to the following test methods:

[0164] (1) According to the requirements of ISO-178-2010 standard, a sample strip with a length of 80 mm, a width of 10 mm and a thickness of 4 mm was cut and used for bending test;

[0165] (2) Referring to the national standard GB / T 1634.2-2004, a sample with a length of 80 mm, a width of 10 mm, and a thickness of 4 mm was first prepared, and the bending stress applied was 1.8 MPa for HDT test;

[0166] (3) Prepare a water-absorbing board with a length of 60 mm, a width of 60 mm, and a thickness of 2 mm according to the standard ASTM-D570-2005, and test it according to the test method of plastic water absorption rate. The test time is 24 hours.

[0167] (4) According to the requirements of GB / T6671-2001 standard, a 200mm pipe section was cut for longitudinal shrinkage rate determination;

[0168] (5) The high temperature internal pressure resistance was determined according to GB / T 6111-2018 standard, and the results are shown in Table 1.

[0169] Table 1

[0170]

[0171]

[0172] As can be seen from Table 1, the mechanical properties, heat resistance, water absorption, and high-temperature internal pressure resistance of the fiber-reinforced bio-based copolyamide pipes prepared by the present invention are significantly improved compared with the corresponding properties of fiber-reinforced composite pipes based on PA6 or PA66, and the application fields are more extensive.

Claims

1. A continuous fiber-reinforced bio-based copolyamide pipe, characterized in that, It includes a bio-based copolyamide resin composition and continuous fibers, wherein the mass fraction ratio of the bio-based copolyamide resin composition to the continuous fibers is (10:90)-(50:50). The bio-based copolyamide resin composition comprises: 60-90 parts of bio-based copolyamide resin, 8-25 parts of polyolefin, 3-12 parts of compatibilizer, 0.1-1 parts of antioxidant, 0.1-0.8 parts of coupling agent, and 0.1-1 parts of release agent; the bio-based copolyamide resin contains the following structural units (Ⅰ), (Ⅱ) and (Ⅲ). 、 、 ； The molar ratio of structural unit (Ⅰ) to structural unit (Ⅱ) is 1:(0.1-0.9). The molar ratio of structural unit (Ⅰ) to structural unit (Ⅲ) is 1:(0.1-0.9). The molar ratio of the structural unit (II) to the structural unit (III) is 1:(0.1-1.5). The structural units (Ⅰ), (Ⅱ) and (Ⅲ) are connected by amide bonds; The relative viscosity of the bio-based copolyamide resin is 2.0~3.2, and the polyolefin is selected from one or more of polyethylene, polypropylene, and polybutene.

2. The continuous fiber-reinforced bio-based copolyamide pipe according to claim 1, characterized in that, The number-average molecular weight of the bio-based copolyamide resin is 20,000 to 70,000. And / or, the water content of the bio-based copolyamide resin is 500~2000ppm; And / or, the melting point of the bio-based copolyamide resin is 260-330°C; And / or, the content of the bio-based copolyamide resin is 68-83 parts.

3. The continuous fiber-reinforced bio-based copolyamide pipe according to claim 2, characterized in that, The content of the bio-based copolyamide resin is 68 parts, 70 parts, 71 parts, 75 parts, 78 parts, 80 parts, and 83 parts.

4. The continuous fiber-reinforced bio-based copolyamide pipe according to claim 1, characterized in that, The content of the polyolefin is 10-23 parts; And / or, the compatibilizer is selected from one or more of polyolefin-grafted maleic anhydride compatibilizers, polyolefin-grafted methyl ester acrylic compatibilizers, and rubber elastomer-grafted maleic anhydride compatibilizers; And / or, the antioxidant is selected from one or more of hindered phenolic antioxidants, hindered amine antioxidants, and phosphite antioxidants; And / or, the coupling agent is selected from one or more of silane coupling agents, carbonate coupling agents, and aluminate coupling agents; And / or, the release agent is selected from oleamide and / or erucamide; and / or, the content of the release agent is 0.1-0.5 parts.

5. The continuous fiber-reinforced bio-based copolyamide pipe according to claim 4, characterized in that, The content of the polyolefin is 10 parts, 14 parts, 16 parts, 20 parts, and 23 parts.

6. The continuous fiber-reinforced bio-based copolyamide pipe according to claim 4, characterized in that, The compatibilizer is selected from one or more of PP-g-MAH, POE-g-MAH, POE-g-GMA or EPDM-g-MAH; and / or, the content of the compatibilizer is 4-9 parts.

7. The continuous fiber-reinforced bio-based copolyamide pipe according to claim 4, characterized in that, The antioxidant is selected from one or more of antioxidant 168, antioxidant 1098, antioxidant 1010 and antioxidant S9228; and / or, the content of the antioxidant is 0.2-1.0 parts.

8. The continuous fiber-reinforced bio-based copolyamide pipe according to claim 4, characterized in that, The coupling agent is a silane-based coupling agent; and / or, the content of the coupling agent is 0.3-0.8 parts.

9. The continuous fiber-reinforced bio-based copolyamide pipe according to claim 6, characterized in that, The compatibilizer content is 5.8 parts, 7 parts, 7.6 parts, 8 parts, and 8.2 parts.

10. The continuous fiber-reinforced bio-based copolyamide pipe according to claim 4, characterized in that, The antioxidant content is 0.3 parts, 0.5 parts, 0.6 parts, 0.7 parts, and 0.8 parts.

11. The continuous fiber-reinforced bio-based copolyamide pipe according to claim 8, characterized in that, The silane coupling agent is coupling agent KH550, coupling agent KH560, or coupling agent KH570.

12. The continuous fiber-reinforced bio-based copolyamide pipe according to claim 8, characterized in that, The coupling agent is present in amounts of 0.4 parts, 0.5 parts, and 0.7 parts.

13. The continuous fiber-reinforced bio-based copolyamide pipe according to claim 4, characterized in that, The release agent is present in amounts of 0.2 parts, 0.3 parts, and 0.4 parts.

14. The continuous fiber-reinforced bio-based copolyamide pipe according to claim 1, characterized in that, The continuous fiber includes one or more of carbon fiber, glass fiber, silicon carbide fiber, basalt fiber, natural flax fiber, aramid fiber, semi-aromatic polyamide fiber, or polyolefin fiber.

15. The continuous fiber-reinforced bio-based copolyamide pipe according to claim 14, characterized in that, The continuous fiber is a continuous long fiber.

16. The continuous fiber-reinforced bio-based copolyamide pipe according to claim 15, characterized in that, The continuous fiber is a continuous long glass fiber.

17. The continuous fiber-reinforced bio-based copolyamide pipe according to claim 16, characterized in that, The diameter of the single filament of the continuous long glass fiber is 8-15 μm; the linear density of the continuous long glass fiber is 1200-4800 TeX.

18. The continuous fiber-reinforced bio-based copolyamide pipe according to claim 15, characterized in that, The continuous fiber is a continuous long carbon fiber.

19. The continuous fiber-reinforced bio-based copolyamide pipe according to claim 18, characterized in that, The number of monofilaments in the continuous long carbon fiber is 10K-60K; the diameter of the monofilaments in the continuous long carbon fiber is 5-10μm.

20. The continuous fiber-reinforced bio-based copolyamide pipe according to claim 18, characterized in that, The continuous long carbon fiber is a polyacrylonitrile carbon fiber.

21. A method for preparing a continuous fiber-reinforced bio-based copolyamide pipe according to any one of claims 1-20, comprising the following steps: S1. The bio-based copolyamide resin composition is extruded, and the melt enters the impregnation die; S2. The continuous fiber is introduced into the impregnation die head, and the melt and the fiber are impregnated. S3. The impregnated fibers are molded, cooled, drawn and wound to obtain a prepreg tape; S4. Wrap the prepreg tape around the mandrel, roll it, cool it, demold it, and cut it into sections to obtain the final product.

22. The preparation method according to claim 21, characterized in that, In step S1, the extrusion is performed using a twin-screw extruder or a single-screw extruder; And / or, in step S1, the extrusion temperature is 170-340°C; And / or, in step S1, the extrusion speed, expressed in screw rotation speed, is 200-600 rpm; And / or, in step S1, the extrusion process further includes a filtration step, wherein the filtration is performed using a melt filter; And / or, in step S1, the width of the impregnation die head is 100-650mm; And / or, in step S1, the temperature of the impregnation die head is 240-330°C.

23. The preparation method according to claim 22, characterized in that, The extrusion is performed using a twin-screw extruder.

24. The preparation method according to claim 23, characterized in that, The length-to-diameter ratio of the twin-screw extruder is 36:

1.

25. The preparation method according to claim 22, characterized in that, The twin-screw extruder adopts an eight-zone heating mode, with zone 1 to zone 8 temperatures of 205-260℃, 265-305℃, 275-325℃, 275-325℃, 275-325℃, 275-325℃, 275-325℃, and 275-325℃, respectively.

26. The preparation method according to claim 22, characterized in that, In step S1, the extrusion speed is expressed in terms of screw rotation speed, which is 300 rpm or 400 rpm.

27. The preparation method according to claim 22, characterized in that, A twin-screw extruder is used, and the temperature of the melt filter is within the range of 0-15℃ above and below the temperature of the eight zones of the twin-screw extruder.

28. The preparation method according to claim 22, characterized in that, In step S1, the temperature of the impregnation die head is 290-330℃.

29. The preparation method according to claim 28, characterized in that, A twin-screw extruder is used, and the temperature of the impregnation die is within the range of 0-15°C above and below the temperature of the eight zones of the twin-screw extruder.

30. The preparation method according to claim 21, characterized in that, In step S2, when the fiber is a continuous long fiber, the introduction includes the following process: the fiber is unwound from the yarn rack by a tension controller, passes through a yarn separating frame, enters a yarn spreading system to fully spread each filament bundle, then enters a yarn drying device for preheating, and then enters an impregnation die; wherein, when the fiber is a continuous long glass fiber, the temperature of the yarn drying device is 70-90℃; when the fiber is a continuous long carbon fiber, the temperature of the yarn drying device is 70-400℃; And / or, in step S3, the molding and cooling are performed using a pressure roller machine; And / or, in step S3, the traction is performed using a traction device, in which further cooling and trimming are carried out; And / or, in step S3, the winding is performed using a winding device; And / or, in step S3, the thickness of the obtained prepreg tape is 0.15-0.4 mm.

31. The preparation method according to claim 30, characterized in that, The fiber is a continuous long glass fiber, and the temperature of the yarn drying device is 80°C or 85°C.

32. The preparation method according to claim 30, characterized in that, The fiber is a continuous long carbon fiber, and the temperature of the drying device is 80℃, 100℃, 250℃, 300℃ or 350℃.

33. The preparation method according to claim 30, characterized in that, In step S3, the molding and cooling processes are performed using a four-roll mill.

34. The preparation method according to claim 33, characterized in that, The temperature of the internal circulating water in the four-roll mill is 15-40℃.

35. The preparation method according to claim 30, characterized in that, In step S3, the traction speed is 5-20 m / min.

36. The preparation method according to claim 30, characterized in that, In step S3, the winding device is an automatic winding machine.

37. The preparation method according to claim 21, characterized in that, In step S4, the winding temperature is 280-350℃, which is obtained by hot air heating or infrared heating; And / or, in step S4, the winding speed is 1-30 m / min; And / or, in step S4, the winding angle is between 30° and 75°.

38. The preparation method according to claim 37, characterized in that, In step S4, the winding speed is 5-20 m / min.

39. The preparation method according to claim 37, characterized in that, In step S4, the winding angle is in the range of 40°-60°.

40. The application of any one of the continuous fiber reinforced bio-based copolyamide pipes according to claims 1-20 in the fields of building water supply and drainage pipes, heating pipes, gas pipes, electrical conduits, industrial pipes, and submarine pipeline facilities.

Images