A bio-based copolyamide composite for pipe and a method for preparing the same

Abstract

The present application relates to a kind of pipe with bio-based copolyamide composite material and its preparation method, including the following weight parts of component: bio-based copolyamide 50-75 parts, polyolefin 3-15 parts, fiber 10-30 parts, compatible agent 3-10 parts, antioxidant 0.1-2 parts, coupling agent 0.1-2 parts, cold resistance agent 0.1-5 parts and filling 1-5 parts;Wherein, the bio-based copolyamide is formed by pentanediamine (A) and dicarboxylic acid component (B), total is 100 mole %;The dicarboxylic acid component (B) is composed of (B1) 20-100 mole proportion of adipic acid, (B2) 10-80 mole proportion of terephthalic acid, and (B3) 0-40 mole proportion of isophthalic acid;(B1), (B2) and (B3) total is 100 mole proportion.The pipe with bio-based copolyamide composite material provided by the present application has the characteristics of high pressure resistance, good temperature resistance, low water absorption, high strength, good toughness, especially excellent toughness at low temperature, can be widely used in a variety of scenes under high and low temperature.

Description

Technical Field

[0001] This invention relates to a bio-based copolyamide composite material for pipes and its preparation method. Background Technology

[0002] Plastic pipes have rapidly developed due to their advantages such as light weight and corrosion resistance, gradually replacing metal pipes. Polyethylene (PE), polypropylene (PP), and rigid PVC (PVC) pipes are the most common. However, these general-purpose plastics are still unsuitable for harsh environments, such as high temperature and high pressure. Among engineering plastics, nylon possesses excellent comprehensive properties, such as high strength, high heat distortion temperature, and good mechanical properties under high temperature and high pressure. However, nylon itself suffers from high water absorption, resulting in reduced strength after water absorption, and poor toughness at room temperature and low temperatures, limiting its application in dry and cold environments.

[0003] To improve the toughness of nylon, researchers have conducted numerous studies on preparation processes and material selection, but none have been able to achieve a good balance between low-temperature toughness and high-temperature resistance. Therefore, there is an urgent need to provide a thermoplastic composite material with good mechanical properties at both high and low temperatures. Summary of the Invention

[0004] To overcome the shortcomings of the existing technology, this invention provides a bio-based copolyamide composite material for pipes and its preparation method. The copolyamide composite material for pipes provided by this invention is resistant to high and low temperatures, has high strength and good toughness, thus broadening the application scenarios of pipes; moreover, it is lightweight, better meeting the demand for lightweight pipes.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] The first aspect of this invention provides a bio-based copolyamide composite material for pipes, comprising the following components in parts by weight: 50-75 parts of bio-based copolyamide, 3-15 parts of polyolefin, 10-30 parts of fiber, 3-10 parts of compatibilizer, 0.1-2 parts of antioxidant, 0.1-2 parts of coupling agent, 0.1-5 parts of cold-resistant agent, and 1-5 parts of filler; wherein the bio-based copolyamide is formed from pentanediamine (A) and dicarboxylic acid component (B), with a total of 100 mol%; the dicarboxylic acid component (B) is composed of (B1) 20-100 mol of adipic acid, (B2) 10-80 mol of terephthalic acid, and (B3) 0-40 mol of isophthalic acid; the total of (B1), (B2), and (B3) is 100 mol%.

[0007] In some specific embodiments, the bio-based copolyamide has a melting point of 260-330°C, preferably 270-300°C. The melting point of the copolyamide is determined according to ASTM D3418-2003.

[0008] In some specific embodiments, the relative viscosity of the bio-based copolyamide is 2.0-2.7. The relative viscosity of the copolyamide is measured using the Ubbelohde viscometer method with concentrated sulfuric acid: 0.5 ± 0.0002 g of dried polyamide sample is accurately weighed, dissolved in 50 mL of concentrated sulfuric acid (98%), and the flow time t0 of the concentrated sulfuric acid and the flow time t0 of the polyamide solution are measured and recorded in a 25°C constant temperature water bath. The relative viscosity ηr = t / t0, where: t: solution flow time; t0: solvent flow time.

[0009] In some specific embodiments, the molar ratio of the pentanediamine and dicarboxylic acid components is (1-1.1):1, for example, 1.05:1.

[0010] In some specific embodiments, the preparation method of the bio-based copolyamide includes the following steps: preparing a polyamide salt solution by mixing pentanediamine (A), dicarboxylic acid component (B) and water, transferring the polyamide salt solution to a polymerization device for heating and polymerization, and obtaining the bio-based copolyamide.

[0011] In some specific embodiments, the dicarboxylic acid component consists of (B1) 40 to 90 molar proportions of adipic acid, (B2) 10 to 60 molar proportions of terephthalic acid, and (B3) 0 molar proportions of isophthalic acid.

[0012] Preferably, the molar ratio of adipic acid to terephthalic acid is 1:(0.1-1.5), more preferably 1:(0.55-0.85), for example 1:0.72.

[0013] In some specific embodiments, the preparation method of the bio-based copolyamide includes the following steps: (1) Under an inert gas atmosphere, water, pentanediamine, terephthalic acid, and adipic acid are mixed to prepare a polyamide salt aqueous solution with a concentration of 30-75 wt%; (2) The polyamide salt aqueous solution is transferred to a polymerization device (e.g., a polymerization kettle), heated under an inert gas atmosphere, so that the temperature in the reaction system rises to 230-310°C and the pressure rises to 0.7-2.5 MPa, and is maintained for 60-180 minutes; then, the pressure is reduced to atmospheric pressure within 30-120 minutes by venting, while the temperature is increased to 260-340°C; vacuum is drawn to reduce the pressure to -(0.02-0.08) MPa, and is maintained for 30-120 minutes to obtain a melt; (3) The melt is stretched and granulated to obtain the bio-based copolyamide PA56T.

[0014] In some specific embodiments, the bio-based copolyamide PA56T has a relative viscosity of 2.05-2.65 and a melting point of 260-330℃.

[0015] In some specific embodiments, the bio-based copolyamide PA56T has a relative viscosity of 2.24-2.45 and a melting point of 270-300℃.

[0016] In some specific embodiments, the dicarboxylic acid component is composed of (B1) 20-50 molar proportions of adipic acid, (B2) 30-65 molar proportions of terephthalic acid, and (B3) 10-40 molar proportions of isophthalic acid.

[0017] Preferably, the dicarboxylic acid component is composed of (B1) 25-40 molar proportions of adipic acid, (B2) 40-60 molar proportions of terephthalic acid, and (B3) 15-35 molar proportions of isophthalic acid.

[0018] Preferably, the molar ratio of terephthalic acid to isophthalic acid is (1.5-5):1, and more preferably (2-3.5):1.

[0019] In some specific embodiments, the preparation method of the bio-based copolyamide includes the following steps: (1) Under an inert gas atmosphere, water, pentanediamine, terephthalic acid, adipic acid and isophthalic 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 device (e.g., a polymerization kettle), heated under an inert gas atmosphere for 1-2 hours to raise the pressure in the reaction system to 1.5-3.2 MPa, vented, and pressure maintained for 2-5 hours, so that the temperature of the reaction system is 232-270℃ at the end of the pressure maintenance, and then the pressure is reduced to 0-0.2 MPa, and the temperature of the reaction system is 230-300℃ after the pressure reduction; a vacuum is drawn to a vacuum degree of -0.02 MPa to -0.1 MPa, and the vacuum time is 20-60 minutes to obtain a melt; (3) The melt is stretched and granulated to obtain the bio-based copolyamide PA56TI.

[0020] In some specific embodiments, the bio-based copolyamide PA56TI has a relative viscosity of 2.55-2.65 and a melting point of 260-285℃.

[0021] In some specific embodiments, when preparing the above-mentioned bio-based copolyamide PA56T or PA56TI, the concentration of the polyamide salt aqueous solution can be 45wt%, 50wt%, 55wt%, 60wt%, 65wt%, 70wt%, or 75wt% (mass percentage).

[0022] In some specific embodiments, when preparing the above-mentioned bio-based copolyamide PA56T or PA56TI, the inert gas includes, for example, nitrogen, argon or helium.

[0023] In some specific embodiments, the type of fiber is carbon fiber, glass fiber, basalt fiber or aramid fiber.

[0024] In some specific embodiments, the fiber is glass fiber; glass fiber is conventional in the art, and preferably, the monofilament diameter of the glass fiber is 5-15um and the length is 0.5-5mm, for example, ECS10-4.5-T435N purchased from Taishan Fiberglass, which has a monofilament diameter of 10um and a length of 4.5mm.

[0025] In some specific embodiments, the fiber is carbon fiber; carbon fiber is conventional in the art, and preferably, the diameter of the carbon fiber monofilament is 5-10μm and the length is 0.5-6mm, for example, DSC-4mm purchased from Texas Carbon Vanbo Composites Co., Ltd., whose fiber monofilament diameter is 8μm and the length is 4mm.

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

[0027] 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.

[0028] In some specific embodiments, the antioxidant may be selected from one or more of hindered phenolic antioxidants, 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 (CAS23128-74-7). The phosphite antioxidant may be conventional in the art, such as antioxidant 168 (CAS 31570-04-4) and antioxidant S9228.

[0029] Preferably, the antioxidant is selected from one or more of antioxidant 168, antioxidant 1098, antioxidant 1010 and antioxidant S9228.

[0030] In some specific embodiments, the coupling agent is selected from one or more of silane coupling agents, carbonate coupling agents, and aluminate coupling agents; preferably, it is a silane coupling agent, such as coupling agent KH550, coupling agent KH560, or coupling agent KH570 purchased from Nanjing Jingtianwei Chemical Co., Ltd.

[0031] In some specific embodiments, the cold-resistant agent is selected from at least one of dioctyl adipate (DOA), dioctyl sebacate (DOS), dibutyl sebacate, and maleic anhydride-grafted EPDM rubber copolymer; preferably, it is dioctyl adipate and / or dioctyl sebacate.

[0032] In some specific embodiments, the filler is selected from one or more of talc, carbon black, CaSO4 whiskers, attapulgite, glass beads, and kaolin.

[0033] A second aspect of the present invention provides a method for preparing a bio-based copolyamide composite material for pipes, comprising the following steps:

[0034] S1 is a premix obtained by mixing bio-based copolyamide, polyolefin, compatibilizer, antioxidant, coupling agent, cold resistant agent and filler;

[0035] S2 melt-extrudes the premix and fiber, cools, and pelletizes to obtain a bio-based copolyamide composite material for pipes.

[0036] In some specific embodiments, in step S2, the melt extrusion is carried out using a twin-screw extruder or a single-screw extruder, preferably a twin-screw extruder.

[0037] In some specific embodiments, the twin-screw extruder adopts a five-zone heating mode. Preferably, the temperature of zone one is 220-270°C, the temperature of zone two is 240-290°C, the temperature of zone three is 280-310°C, the temperature of zone four is 290-310°C, and the temperature of zone five is 290-310°C. For example, the processing temperatures from zone one to zone five are 250°C, 280°C, 300°C, 305°C, and 305°C, respectively.

[0038] In some specific embodiments, the die head temperature of the twin-screw extruder is 290-320°C.

[0039] In some specific embodiments, the screw speed of the twin-screw extruder is 300-500 r / min.

[0040] In this invention, the premix is ​​fed into a twin-screw extruder through the main feed port, and the fiber is fed into the twin-screw extruder through the side feed port. The amount of fiber added is adjusted by regulating the feeding rate.

[0041] In some specific embodiments, the main feed speed of the twin-screw extruder is 10-100 r / min; the side feed speed of the twin-screw extruder is 1-100 r / min.

[0042] In some specific embodiments, the length-to-diameter ratio of the twin-screw extruder is (30-50):1, preferably 36:1.

[0043] In some specific implementations, water cooling is used.

[0044] In some specific embodiments, the pelletizing can be performed using a pelletizer commonly used in the art.

[0045] In some specific embodiments, in step S2, the fiber-reinforced polyamide composite material is in particle shape, and the particle length is 3-5 mm, for example 4 mm.

[0046] The pipes made from the above-mentioned bio-based copolyamide composite material can be prepared using conventional processes in the field, such as extrusion using a pipe extruder, cooling and shaping, and cutting the pipes to the preset dimensions.

[0047] The third aspect of this invention provides the application of a bio-based copolyamide composite material for pipes in the aerospace, military, automotive, sporting goods, building materials, or electronic and electrical applications.

[0048] 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.

[0049] Compared with the prior art, the positive and progressive effects of the present invention are as follows: The present invention provides a bio-based copolyamide composite material for pipes, using bio-based copolyamide as the matrix material and modifying it with inexpensive fibers. On the one hand, it can reduce costs, and on the other hand, it can enhance the mechanical strength of nylon and reduce the water absorption of nylon, enabling its application in the field of lightweighting. At the same time, by compounding with polyolefins, cold-resistant agents and other additives, the resulting bio-based copolyamide composite material has low water absorption, high and low temperature resistance, and excellent mechanical properties, and can be widely used in aerospace, military, automotive materials, sports equipment, building materials or electronic and electrical appliances. Detailed Implementation

[0050] 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.

[0051] Glass fiber was purchased from Taishan Glass Fiber's ECS10-4.5-T435N, with a diameter of 10µm and a length of 4.5mm; carbon fiber was purchased from Dezhou Carbon Vanbo Composites Co., Ltd.'s DSC-4mm, with a diameter of 8µm and a length of 4mm; coupling agent was purchased from Nanjing Jingtianwei Chemical Co., Ltd.; polyethylene PE100S was purchased from Jilin Petrochemical; polypropylene PP212E was purchased from Borealis; antioxidant was purchased from BASF Group, Germany; compatibilizer was purchased from Shanghai Jiayirong Polymer Co., Ltd.; other raw materials were commercially available unless otherwise specified.

[0052] Preparation Example 1

[0053] (1) Under a nitrogen atmosphere, water, pentanediamine, and dicarboxylic acid (amic acid and terephthalic acid in a molar ratio of 1:0.72) were mixed to prepare a polyamide salt aqueous solution with a concentration of 65 wt%; the molar ratio of pentanediamine and dicarboxylic acid was 1.05:1; (2) The polyamide salt aqueous solution was transferred to a polymerization reactor and heated under a nitrogen atmosphere. The temperature inside the reactor was raised to 290°C and the pressure inside the polymerization device was raised to 1.6 MPa and maintained for 110 minutes. Then, the pressure was reduced to atmospheric pressure within 85 minutes, while the temperature inside the polymerization device was raised to 300°C. Vacuum was drawn to reduce the pressure to -0.05 MPa and maintained for 60 minutes to obtain a melt. The melt was drawn into strips and granulated to obtain bio-based copolyamide PA56T (relative viscosity 2.31, melting point 290°C).

[0054] Preparation Example 2

[0055] (1) Under a nitrogen atmosphere, pentanediamine, dicarboxylic acid (adipic acid, terephthalic acid, and isophthalic acid in a molar ratio of 3:5:2) and water were mixed evenly to prepare a 50 wt% polyamide salt aqueous solution. 0.1% sodium hypophosphite (as a percentage of the total molar amount of dicarboxylic acid) of heat stabilizer was added. The molar ratio of pentanediamine to dicarboxylic acid was 1.05:1. (2) The polyamide salt aqueous solution was transferred to a polymerization reactor and heated under a nitrogen atmosphere for 1.5 h, raising the pressure in the reaction system to 2.00 MPa. a. Exhaust the gas, maintain pressure for 3 hours. When the pressure is maintained, the temperature of the reaction system is 243°C. Then reduce the pressure to 0.005 MPa (gauge pressure) and reduce the pressure for 1 hour. When the pressure is reduced, the temperature of the reaction system is 288°C. Vacuum is maintained at -0.08 MPa for 45 minutes. The temperature after vacuum is 288°C, and the melt is obtained. (3) The melt is stretched and granulated to obtain bio-based copolyamide PA56TI (relative viscosity 2.61, melting point 270°C).

[0056] Example 1

[0057] S1. Add 60 parts of bio-based copolyamide PA56T, 8 parts of polyethylene, 0.7 parts of antioxidant 1098, 6.4 parts of PE-g-MAH, 0.7 parts of coupling agent KH550, 1.2 parts of dioctyl adipate and 3 parts of talc to a high-speed mixer and mix evenly to obtain a premix.

[0058] S2. The premix is ​​fed into the twin-screw extruder through the main feed port, and 20 parts of glass fiber are added into the twin-screw extruder through the side feed port. After melt extrusion, cooling and pelletizing, fiber-reinforced copolyamide particles with a length of 4 mm are obtained.

[0059] In step S2, the melt extrusion can be performed using a twin-screw extruder. The twin-screw extruder adopts a five-zone heating mode, with processing temperatures from zone 1 to zone 5 being 250℃, 280℃, 300℃, 305℃, and 305℃ respectively; the die head temperature is 305℃; the screw speed is 400 r / min; the main feed speed is 30 r / min; the side feed speed is 10 r / min; and the length-to-diameter ratio of the twin-screw extruder is 36:1.

[0060] Example 2

[0061] S1. Add 65 parts of bio-based polyamide PA56TI, 5 parts of polyethylene, 0.9 parts of antioxidant 1098, 3 parts of PE-g-MAH, 1.0 part of coupling agent KH550, 1.1 parts of dioctyl adipate and 1 part of talc to a high-speed mixer and mix evenly to obtain a premix.

[0062] S2. The premix is ​​fed into the twin-screw extruder through the main feed port, and 23 parts of glass fiber are added into the twin-screw extruder through the side feed port. After melt extrusion, cooling and pelletizing, fiber-reinforced copolyamide particles with a length of 4 mm are obtained.

[0063] In step S2, the melt extrusion can be performed using a twin-screw extruder. The twin-screw extruder adopts a five-zone heating mode, with processing temperatures from zone 1 to zone 5 being 250℃, 280℃, 300℃, 305℃, and 305℃ respectively; the die head temperature is 300℃; the screw speed is 400 r / min; the main feed speed is 30 r / min; the side feed speed is 10 r / min; and the length-to-diameter ratio of the twin-screw extruder is 36:1.

[0064] Example 3

[0065] S1. Add 67 parts of bio-based copolyamide PA56T, 5 parts of polypropylene, 0.7 parts of antioxidant 168, 3 parts of PP-g-MAH, 0.6 parts of coupling agent KH560, 1.7 parts of dioctyl adipate and 4 parts of talc to a high-speed mixer and mix evenly to obtain a premix.

[0066] S2. The premix is ​​fed into the twin-screw extruder through the main feed port, and 18 parts of glass fiber are added into the twin-screw extruder through the side feed port. After melt extrusion, cooling and pelletizing, fiber-reinforced copolyamide particles with a length of 4 mm are obtained.

[0067] In step S2, the melt extrusion can be performed using a twin-screw extruder. The twin-screw extruder adopts a five-zone heating mode, with processing temperatures from zone 1 to zone 5 being 250℃, 280℃, 300℃, 305℃, and 305℃ respectively; the die head temperature is 305℃; the screw speed is 400 r / min; the main feed speed is 30 r / min; the side feed speed is 10 r / min; and the length-to-diameter ratio of the twin-screw extruder is 36:1.

[0068] Example 4

[0069] S1. Add 55 parts of bio-based copolyamide PA56TI, 7 parts of polypropylene, 0.5 parts of antioxidant 168, 6 parts of PP-g-MAH, 1 part of coupling agent KH560, 1.5 parts of dioctyl adipate and 3 parts of CaSO4 to a high-speed mixer and mix evenly to obtain a premix.

[0070] S2. The premix is ​​fed into the twin-screw extruder through the main feed port, and 26 parts of glass fiber are added into the twin-screw extruder through the side feed port. After melt extrusion, cooling and pelletizing, fiber-reinforced copolyamide particles with a length of 4 mm are obtained.

[0071] In step S2, the melt extrusion can be performed using a twin-screw extruder. The twin-screw extruder adopts a five-zone heating mode, with processing temperatures from zone 1 to zone 5 being 250℃, 280℃, 300℃, 305℃, and 305℃ respectively; the die head temperature is 300℃; the screw speed is 400 r / min; the main feed speed is 30 r / min; the side feed speed is 10 r / min; and the length-to-diameter ratio of the twin-screw extruder is 36:1.

[0072] Example 5

[0073] S1. Add 52 parts of bio-based copolyamide PA56TI, 8 parts of polypropylene, 0.6 parts of antioxidant 168, 5.5 parts of PP-g-MAH, 1 part of coupling agent KH560, 2.4 parts of dioctyl sebacate and 2.5 parts of CaSO4 to a high-speed mixer and mix evenly to obtain a premix.

[0074] S2. The premix is ​​fed into the twin-screw extruder through the main feed port, and 28 parts of glass fiber are added into the twin-screw extruder through the side feed port. After melt extrusion, cooling and pelletizing, fiber-reinforced copolyamide particles with a length of 4 mm are obtained.

[0075] In step S2, the melt extrusion can be performed using a twin-screw extruder. The twin-screw extruder adopts a five-zone heating mode, with processing temperatures from zone 1 to zone 5 being 250℃, 280℃, 300℃, 305℃, and 305℃ respectively; the die head temperature is 300℃; the screw speed is 400 r / min; the main feed speed is 30 r / min; the side feed speed is 10 r / min; and the length-to-diameter ratio of the twin-screw extruder is 36:1.

[0076] Example 6

[0077] S1. Add 70 parts of bio-based copolyamide PA56T, 5 parts of polypropylene, 0.5 parts of antioxidant 168, 3 parts of PP-g-MAH, 0.4 parts of coupling agent KH560, 3.1 parts of dioctyl adipate and 3 parts of CaSO4 to a high-speed mixer and mix evenly to obtain a premix.

[0078] S2. The premix is ​​fed into the twin-screw extruder through the main feed port, and 15 parts of glass fiber are added into the twin-screw extruder through the side feed port. After melt extrusion, cooling and pelletizing, fiber-reinforced copolyamide particles with a length of 4 mm are obtained.

[0079] In step S2, the melt extrusion can be performed using a twin-screw extruder. The twin-screw extruder adopts a five-zone heating mode, with processing temperatures from zone 1 to zone 5 being 250℃, 280℃, 300℃, 305℃, and 305℃ respectively; the die head temperature is 305℃; the screw speed is 400 r / min; the main feed speed is 30 r / min; the side feed speed is 10 r / min; and the length-to-diameter ratio of the twin-screw extruder is 36:1.

[0080] Example 7

[0081] The same method as in Example 1 was followed, except that carbon fiber was used when preparing the bio-based copolyamide composite material for pipes.

[0082] Example 8

[0083] The same method as in Example 2 was followed, except that carbon fiber was used when preparing the bio-based copolyamide composite material for pipes.

[0084] Example 9

[0085] The same method as in Example 3 was followed, except that carbon fiber was used when preparing the bio-based copolyamide composite material for pipes.

[0086] Example 10

[0087] The same method as in Example 4 was followed, except that carbon fiber was used when preparing the bio-based copolyamide composite material for pipes.

[0088] Example 11

[0089] The same method as in Example 5 was followed, except that carbon fiber was used when preparing the bio-based copolyamide composite material for pipes.

[0090] Example 12

[0091] The same method as in Example 6 was followed, except that carbon fiber was used when preparing the bio-based copolyamide composite material for pipes.

[0092] Comparative Example 1

[0093] S1. Add 45 parts of bio-based copolyamide PA56T, 23 parts of polyethylene, 0.7 parts of antioxidant 1098, 6.4 parts of PE-g-MAH, 0.7 parts of coupling agent KH550, 1.2 parts of dioctyl adipate and 3 parts of talc to a high-speed mixer and mix evenly to obtain a premix.

[0094] S2. The premix is ​​fed into the twin-screw extruder through the main feed port, and 20 parts of glass fiber are added into the twin-screw extruder through the side feed port. After melt extrusion, cooling and pelletizing, fiber-reinforced copolyamide particles with a length of 4 mm are obtained.

[0095] In step S2, the melt extrusion can be performed using a twin-screw extruder. The twin-screw extruder adopts a five-zone heating mode, with the processing temperatures from zone 1 to zone 5 to the die head being 250℃, 280℃, 300℃, 320℃, and 320℃ respectively; the die head temperature is 325℃; the screw speed is 400 r / min; the main feed speed is 30 r / min; the side feed speed is 10 r / min; and the length-to-diameter ratio of the twin-screw extruder is 36:1.

[0096] Comparative Example 2

[0097] S1. Add 60 parts of PA6 (purchased from Xinhui Meda Company, viscosity 2.3, terminal amino content 54 mmol / kg, melting point 223℃), 8 parts of polyethylene, 0.5 parts of antioxidant 1098, 6.5 parts of PE-g-MAH, 1.5 parts of coupling agent KH550, 2 parts of dioctyl adipate and 1.5 parts of talc to a high-speed mixer and mix evenly to obtain a premix;

[0098] S2. The premix is ​​fed into the twin-screw extruder through the main feed port, and 20 parts of glass fiber are fed into the twin-screw extruder through the side feed port. After melt extrusion, cooling and pelletizing, fiber-reinforced polyamide particles with a length of 4 mm are obtained.

[0099] In step S2, the melt extrusion can be performed using a twin-screw extruder. The twin-screw extruder adopts a five-zone heating mode, with processing temperatures from zone 1 to zone 5 being 210℃, 220℃, 230℃, 235℃, and 235℃ respectively; the die head temperature is 240℃; the screw speed is 280 r / min; the main feed speed is 30 r / min; and the length-to-diameter ratio of the twin-screw extruder is 36:1.

[0100] Comparative Example 3

[0101] S1. Add 60 parts of PA66 (purchased from DuPont, viscosity 2.6, terminal amino content 48 mmol / kg, melting point 255℃), 8 parts of polyethylene, 0.5 parts of antioxidant 1098, 6.5 parts of PE-g-MAH, 1.5 parts of coupling agent KH550, 2 parts of dioctyl adipate and 1.5 parts of talc to a high-speed mixer and mix evenly to obtain a premix;

[0102] S2. The premix is ​​fed into the twin-screw extruder through the main feed port, and 20 parts of glass fiber are fed into the twin-screw extruder through the side feed port. After melt extrusion, cooling and pelletizing, fiber-reinforced polyamide particles with a length of 4 mm are obtained.

[0103] In step S2, the melt extrusion can be performed using a twin-screw extruder. The twin-screw extruder adopts a five-zone heating mode, with processing temperatures from zone 1 to zone 5 being 260℃, 260℃, 265℃, 270℃, and 270℃ respectively; the die head temperature is 280℃; the screw speed is 400 r / min; the main feed speed is 30 r / min; and the length-to-diameter ratio of the twin-screw extruder is 36:1.

[0104] The bio-based copolyamide composites prepared in the above examples and comparative examples were subjected to performance tests according to the following methods, and the results are shown in Table 1:

[0105] (1) According to the requirements of GB / T1447-2005 standard, a strip with a length of 180 mm, a width of 10 mm, and a thickness of 3.8 mm was prepared for tensile testing;

[0106] (2) Referring to the national standard GB / T 1634.2-2004, a strip 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;

[0107] (3) Referring to the standard ASTM-D570-2005, first prepare a water-absorbing board with a length of 60mm, a width of 60mm, and a thickness of 2mm, and test it according to the test method of plastic water absorption rate. The test time is 24 hours.

[0108] (4) In accordance with the requirements of GB / T 1843-2008 standard, notched strips with a length of 80 mm, a width of 10 mm, and a thickness of 4 mm were prepared and subjected to impact testing at 23℃; after freezing at -40℃ for 4 h, impact testing was also conducted.

[0109] (5) The high temperature resistance to internal pressure was determined according to GB / T 6111-2018 standard.

[0110] Table 1

[0111]

[0112] As can be seen from Table 1, the bio-based copolyamide composite material of the present invention has good high pressure resistance, good temperature resistance, low water absorption, high strength, and good toughness. In particular, it still has excellent toughness at low temperatures and can be widely used in various scenarios at high and low temperatures.

[0113] The embodiments described in this invention are for illustrative purposes only and are not intended to limit the scope of protection of this invention. Those skilled in the art can make various other substitutions, changes and improvements within the scope of this invention. Therefore, this invention is not limited to the above embodiments, but is only defined by the claims.

Claims

1. A bio-based copolyamide composite for pipe applications, characterized in that, The product comprises the following components in parts by weight: 50-75 parts bio-based copolyamide, 3-15 parts polyolefin, 10-30 parts fiber, 3-10 parts compatibilizer, 0.1-2 parts antioxidant, 0.1-2 parts coupling agent, 0.1-5 parts cold-resistant agent, and 1-5 parts filler; wherein the bio-based copolyamide is formed from pentanediamine (A) and dicarboxylic acid component (B), with a total content of 100 mol%; the dicarboxylic acid component (B) consists of (B1) adipic acid in a 20-100 mol proportion, (B2) terephthalic acid in a 10-80 mol proportion, and (B3) The composition is composed of isophthalic acid in a molar ratio of 0-40; the sum of (B1), (B2) and (B3) is 100 molar ratio, and the cold-resistant agent is selected from at least one of dioctyl adipic acid, dioctyl sebacate, and dibutyl sebacate; the molar ratio of adipic acid and terephthalic acid is 1:(0.55-0.85).

2. The bio-based copolyamide composite material for pipe applications according to claim 1, characterized in that, The dicarboxylic acid component consists of (B1) 40 to 90 molar proportions of adipic acid, (B2) 10 to 60 molar proportions of terephthalic acid, and (B3) 0 molar proportions of isophthalic acid. And / or, the molar ratio between the pentanediamine (A) and the dicarboxylic acid component (B) is (1-1.1):

1.

3. The bio-based copolyamide composite material for pipe applications according to claim 1, characterized in that, The dicarboxylic acid component is composed of (B1) 20-50 molar proportion of adipic acid, (B2) 30-65 molar proportion of terephthalic acid, and (B3) 10-40 molar proportion of isophthalic acid; the molar ratio of terephthalic acid to isophthalic acid is (1.5-5):

1.

4. The bio-based copolyamide composite material for pipe applications according to claim 1, characterized in that, The dicarboxylic acid component consists of (B1) 25-40 molar proportions of adipic acid, (B2) 40-60 molar proportions of terephthalic acid, and (B3) 15-35 molar proportions of isophthalic acid. And / or, the molar ratio of terephthalic acid to isophthalic acid is (2-3.5):

1.

5. The bio-based copolyamide composite material for pipe applications according to claim 1, wherein, The bio-based copolyamide has a melting point of 260-330°C and / or a relative viscosity of 2.0-2.

7.

6. The bio-based copolyamide composite material for pipe applications as claimed in claim 5, wherein, The bio-based copolyamide has a melting point of 270-300℃.

7. The bio-based copolyamide composite material for pipe applications as claimed in claim 1, wherein, The type of fiber is carbon fiber, glass fiber, basalt fiber or aramid fiber; And / or, the polyolefin is selected from one or more of polyethylene, polypropylene, and polybutene.

8. The bio-based copolyamide composite material for pipe applications according to claim 7, characterized in that, The fiber is glass fiber; the diameter of the glass fiber monofilament is 5-15 μm and the length is 0.5-5 mm.

9. The bio-based copolyamide composite material for pipe applications according to claim 7, characterized in that, The fiber is carbon fiber, and the single filament diameter of the carbon fiber is 5-10 μm and the length is 0.5-6 mm.

10. The bio-based copolyamide composite material for pipe applications as claimed in claim 1, wherein, The compatibilizer is selected from one or more of the following: polyolefin grafted maleic anhydride compatibilizer, polyolefin grafted methyl ester acrylic compatibilizer, and rubber elastomer grafted maleic anhydride compatibilizer. And / or, the antioxidant may be selected from one or more of hindered phenolic antioxidants, hindered amine antioxidants, and phosphite antioxidants.

11. The bio-based copolyamide composite material for pipes according to claim 10, 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 antioxidant is selected from one or more of antioxidant 168, antioxidant 1098, antioxidant 1010 and antioxidant S9228.

12. The bio-based copolyamide composite material for pipe applications according to claim 1, characterized in that, The coupling agent is selected from one or more of silane coupling agents, carbonate coupling agents, and aluminate coupling agents; and / or, The filler is selected from one or more of talc, carbon black, CaSO4 whiskers, attapulgite, glass beads, and kaolin.

13. The bio-based copolyamide composite material for pipe applications as claimed in claim 12, wherein, The coupling agent is selected from silane coupling agents, specifically coupling agent KH550, coupling agent KH560, or coupling agent KH570.

14. A method for preparing a bio-based copolyamide composite material for pipes according to any one of claims 1-13, comprising the following steps: S1 is a premix obtained by mixing bio-based copolyamide, polyolefin, compatibilizer, antioxidant, coupling agent, cold resistant agent and filler; S2 melt-extrudes the premix and fiber, cools, and pelletizes to obtain a bio-based copolyamide composite material for pipes.

15. The method of producing a bio-based copolyamide composite for pipe applications according to claim 14, characterized in that, In step S2, the melt extrusion is performed using a twin-screw extruder; and / or, The twin-screw extruder adopts a five-zone heating mode, with zone 1 temperature of 220~270℃, zone 2 temperature of 240~290℃, zone 3 temperature of 280~310℃, zone 4 temperature of 290~310℃, and zone 5 temperature of 290~310℃. And / or, the die head temperature of the twin-screw extruder is 290-320°C; And / or, the screw speed of the twin-screw extruder is 300-500 r / min; And / or, the length-to-diameter ratio of the twin-screw extruder is (30-50):1; And / or, in step S2, the composite material is in particle shape, and the particle length is 3-5 mm.

16. The application of a bio-based copolyamide composite material for pipes according to any one of claims 1-13 in the aerospace, military, automotive, sporting goods, building materials or electronic and electrical applications.

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