A high-temperature resistant bio-based nylon and its preparation method

Abstract

This invention specifically relates to a high-temperature resistant bio-based nylon and its preparation method. The bio-based nylon comprises the following raw materials in parts by weight: 28-35 parts of bio-based adipic acid, 35-40 parts of bio-based terephthalic acid, 8-10 parts of bio-based furanyl dicarboxylic acid, 50-55 parts of aromatic ring-containing diamine, 1.5-3 parts of nano-carbon filler, 2-4 parts of compatibilizer, 0.5-1.2 parts of aminated nano-boron nitride, 0.3-1.0 parts of antioxidant, and 0.05-0.12 parts of catalyst. This invention forms a semi-aromatic-aliphatic alternating copolymer with excellent temperature resistance through the co-reaction of multiple monomers. By introducing monomers with aromatic ring structures and adding nano-carbon filler and aminated nano-boron nitride to form a thermally conductive / reinforcing network, the resulting bio-based nylon material exhibits good high-temperature resistance, mechanical properties, and flame retardant properties. Furthermore, the high content of bio-based raw materials aligns with the development trend of green and environmentally friendly materials.

Description

Technical Field

[0001] This invention relates to the field of nylon materials and preparation technology, specifically to a high-temperature resistant bio-based nylon and its preparation method. Background Technology

[0002] Polyamide, also known as nylon, is one of the most widely used engineering plastics in the world due to its excellent properties. Based on whether it contains benzene rings in its main chain, nylon can be classified into aliphatic nylon, semi-aromatic nylon, and fully aromatic nylon. Aliphatic nylon possesses good mechanical properties, lubricity, and corrosion resistance, but poor water absorption. Fully aromatic nylon has good mechanical properties and high-temperature resistance, but its high rigidity and melting point significantly limit its application in engineering plastics. Semi-aromatic nylon combines the advantages of both aliphatic and fully aromatic nylons, and its application is particularly significant in high-temperature nylon. However, currently, there are few domestic manufacturers of high-temperature nylon, and their products are relatively limited, all using petroleum-based raw materials, resulting in a high dependence on petroleum resources. Driven by environmental policies, nylon materials made from bio-based raw materials can significantly reduce petroleum dependence, potentially achieving a closed-loop utilization of renewable raw materials and biodegradable products, which is more in line with the requirements of a "circular economy." Therefore, bio-based nylon shows great potential and development prospects in the context of sustainable development, but it also faces significant challenges.

[0003] Compared to traditional petroleum-based high-temperature nylons, bio-based nylons still lag significantly in terms of temperature resistance and mechanical properties. This is mainly because bio-based nylons have a higher proportion of aliphatic segments, which intensify chain segment movement at high temperatures, affecting their temperature resistance. For example, the melting temperature of ordinary PA56 is around 220℃, far lower than that of petroleum-based semi-aromatic nylons, making it fundamentally unable to meet the high-temperature stability requirements of nylon materials in the automotive and electronics industries, which require temperatures exceeding 250℃. To improve the high-temperature resistance of bio-based nylons, common methods include adding large amounts of heat-resistant fillers or introducing monomers such as aromatic rings to enhance their high-temperature performance. However, the addition of large amounts of fillers can easily lead to agglomeration in the system, making it difficult to establish effective interfacial bonding through traditional physical blending. Introducing aromatic rings may also increase melt viscosity, reduce fluidity, leading to increased processing difficulty and limited molecular weight control. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art by providing a high-temperature resistant bio-based nylon and its preparation method.

[0005] This invention provides a high-temperature resistant bio-based nylon, comprising the following raw materials in parts by weight: 28-35 parts of bio-based adipic acid, 35-40 parts of bio-based terephthalic acid, 8-10 parts of bio-based furanyl dicarboxylic acid, 50-55 parts of aromatic ring-containing diamine, 1.5-3 parts of nano-carbon filler, 2-4 parts of compatibilizer, 0.5-1.2 parts of aminated nano-boron nitride, 0.3-1.0 parts of antioxidant, and 0.05-0.12 parts of catalyst.

[0006] In this invention, bio-based terephthalic acid and bio-based furanyl dicarboxylic acid provide rigid aromatic rings, while bio-based adipic acid is used to adjust the material's flexibility. Aromatic ring-containing diamines help improve the high-temperature resistance of the bio-based nylon material. These monomers work together to form a semi-aromatic-aliphatic alternating copolymer with excellent temperature resistance. A thermally conductive reinforcing network is then constructed through the synergistic effect of nano-carbon fillers and aminated nano-boron nitride. Simultaneously, the dispersibility and compatibility of each component in the matrix are significantly improved by the compatibilizer. The long-term damp heat aging protection performance of the bio-based nylon material is enhanced through the combination of antioxidants and catalysts. The resulting bio-based nylon material exhibits good high-temperature resistance, mechanical properties, and anti-aging properties, and has a high bio-based raw material content, aligning with the development trend of green and environmentally friendly materials.

[0007] Furthermore, the aromatic ring-containing diamine is at least one selected from p-phenylenediamine, m-phenylenediamine, and 1,5-pentanediamine. Preferably, the aromatic ring-containing diamine is a compound of p-phenylenediamine and 1,5-pentanediamine in a mass ratio of 1.8-2.5:1. P-phenylenediamine, by introducing a rigid aromatic ring, helps improve the material's high-temperature resistance; 1,5-pentanediamine provides a flexible spacer, which helps improve the system's processability and impact strength. This compounding ensures that the bio-based nylon has good high-temperature resistance while maintaining good mechanical properties and processability.

[0008] Furthermore, the nano-carbon filler is at least one of aminated graphene, carboxylated multi-walled carbon nanotubes, and graphene-multi-walled carbon nanotube hybrid filler. In this invention, the preparation method of the graphene-multi-walled carbon nanotube hybrid filler includes the following steps:

[0009] Step A1: Disperse graphene oxide in dimethylformamide by ultrasonic dispersion, then add 20-30 wt% ethylenediamine, and reflux under heating conditions for 8-12 h. After centrifugation, washing and vacuum drying, obtain amino graphene.

[0010] Step A2: Add multi-walled carbon nanotubes to a mixed acid solution for ultrasonic treatment, and obtain carboxylated multi-walled carbon nanotubes by centrifugation, washing and vacuum drying.

[0011] Step A3: The amino-derived graphene obtained in step A1 and the carboxylated multi-walled carbon nanotubes obtained in step A2 are added to dimethylformamide at a mass ratio of 1-2:1 and ultrasonically dispersed. Then, N,N'-dicyclohexylcarbodiimide and N-hydroxysuccinimide are added and mixed evenly. The mixture is heated and reacted under a nitrogen atmosphere for 10-12 hours. The product is centrifuged, washed and vacuum dried to obtain the graphene-multi-walled carbon nanotube hybrid filler.

[0012] Furthermore, in step A1, the graphene oxide sheet has a diameter of 1-5 μm and an oxygen content of 20-30%.

[0013] Furthermore, in step A2, the multi-walled carbon nanotubes have a diameter of 10-20 nm and a length of 1-2 μm; the mixed acid solution is obtained by mixing sulfuric acid and nitric acid in a volume ratio of 3:1.

[0014] Furthermore, in step A3, the N,N'-dicyclohexylcarbodiimide is 25-40% of the mass of the carboxylated carbon nanofiller, the N-hydroxysuccinimide is 14-25% of the mass of the carboxylated carbon nanofiller, and the heating reaction conditions are 60-65°C for 10-12 hours.

[0015] Furthermore, the preparation of the graphene-multi-walled carbon nanotube hybrid filler also includes: step A4, mixing the graphene-multi-walled carbon nanotube hybrid filler obtained in step A3 with ε-caprolactam, sodium hypophosphite and deionized water and placing it in a reaction vessel, first reacting at 120-130℃ and 0.1-0.3MPa for 0.5-1.5h, then reacting at 150-160℃ and 0.4-0.5MPa for 1-2h, and continuing to react at 210-220℃ and -0.1~0.15MPa for 0.5-1h, extracting the product with boiling water for 20-24h, and then drying it under vacuum to obtain the grafted graphene-multi-walled carbon nanotube hybrid filler.

[0016] Furthermore, in step A4, the mass ratio of the graphene-multi-walled carbon nanotube hybrid filler, ε-caprolactam, and deionized water is 1:8-10:1, and the amount of sodium hypophosphite used is 0.4-0.6 wt% of the graphene-multi-walled carbon nanotube hybrid filler.

[0017] In this invention, the inherent properties of nano-carbon fillers are utilized and they are uniformly dispersed in the matrix to generate a synergistic reinforcement / thermal conductivity effect, thereby significantly improving the high-temperature resistance and mechanical properties of the bio-based nylon. Specifically, aminated graphene and carboxylated multi-walled carbon nanotubes are covalently linked through an amidation reaction to achieve a chemical bonding interface, avoiding phase separation caused by direct physical mixing. Furthermore, one-dimensional fibers of multi-walled carbon nanotubes are intercalated into two-dimensional graphene sheets to form a three-dimensional conductive / reinforcing network, achieving uniform dispersion of raw materials and matrix and multi-dimensional synergistic reinforcement. At the same time, the excellent high specific surface area, high thermal stability, and high strength and toughness of graphene and multi-walled carbon nanotubes are combined, thus significantly improving the temperature resistance, mechanical properties, and crystallinity of the bio-based nylon.

[0018] Further, the compatibilizer is at least one selected from maleic anhydride-grafted nylon, glycidyl methacrylate-grafted nylon, and maleic anhydride and glycidyl methacrylate dimonomer-grafted nylon. The grafting rate of the maleic anhydride-grafted nylon is 1.5-1.8%, and the grafting rate of the glycidyl methacrylate is 0.9-1.2 mmol / g. In this invention, the preparation method of the maleic anhydride and glycidyl methacrylate dimonomer-grafted nylon includes the following steps:

[0019] Step B1: Place the grafted nylon matrix under vacuum drying at 80-90℃ for 12-16 hours, controlling the moisture content to be below 0.05%;

[0020] Step B2: The grafted nylon matrix obtained in step B1, 2.0-3.5 wt% maleic anhydride, 0.3-0.6 wt% dicumyl peroxide and 0.15-0.2 wt% stabilizer are premixed at high speed and then added to a twin-screw extruder.

[0021] Step B3: Inject 3.0-4.5wt% glycidyl methacrylate, 0.1-0.15wt% tert-butyl peroxide, and 0.1-0.2wt% hydroquinone into the melting zone of the twin-screw extruder through the side feed port. Maintain the temperature of the reaction zone and react for 6-8 minutes. Extrude the strips, cool them with water, and granulate them to obtain the crude product.

[0022] Step B4: The crude product from step B3 is extracted with xylene using a Soxhlet extractor. The collected product is placed in methanol and stirred to precipitate. After filtration again, it is dried under vacuum to obtain the maleic anhydride and glycidyl methacrylate bis-monomer grafted nylon.

[0023] Furthermore, in step B1, the grafted nylon matrix is ​​nylon 66 or nylon 610.

[0024] Furthermore, in step B2, the zone temperatures of the twin-screw extruder are specifically as follows: the feed zone temperature is 210-220℃, the melt zone temperature is 230-240℃, the reaction zone temperature is 230-250℃, the die head temperature is 220-230℃, the screw speed is 200-300 rpm, and the residence time is 0.5-2 min.

[0025] In this invention, maleic anhydride and / or glycidyl methacrylate grafted nylon form a chemical bond with the nylon matrix through ester bonds and epoxy groups, which improves the dispersibility and interfacial compatibility of the reaction system, thereby solving the agglomeration problem caused by the addition of raw materials such as nano-carbon fillers and aminated nano-boron nitride.

[0026] Furthermore, the antioxidant is at least one of hindered phenolic antioxidants, phosphite antioxidants, and hindered amine antioxidants. Preferably, the antioxidant is a compound of antioxidant 1098 and antioxidant 168 in a mass ratio of 2:1.

[0027] Furthermore, the catalyst is at least one selected from phosphoric acid, phosphorous acid, hypophosphorous acid, and their salt derivatives.

[0028] This invention also provides a method for preparing the above-mentioned high-temperature resistant bio-based nylon, comprising the following steps:

[0029] Step S1: Dissolve bio-based adipic acid, bio-based terephthalic acid and bio-based furanyl dicarboxylic acid in a mixed solvent of ethanol / water by heating. Then slowly add a solution containing an aromatic ring diamine to adjust the pH of the system to 7-8. After precipitating nylon salt, dry the solution.

[0030] Step S2: Add the nylon salt and catalyst obtained in step S1 to a high-pressure reactor for high-temperature reaction, followed by depressurization reaction to obtain the prepolymer, which is then pulverized for later use.

[0031] Step S3: The prepolymer obtained in step S2, the dehydrated and dried nano-carbon filler, compatibilizer and antioxidant are premixed evenly and fed into a twin-screw extruder for melt blending. Aminated nano-boron nitride is added through the side feed port of the melt zone. When the intrinsic viscosity of the polymer reaches 1.5 dL / g or higher, it is extruded and granulated, water-cooled, pelletized and dried to obtain the high-temperature resistant bio-based nylon.

[0032] Furthermore, in step S2, the high-temperature reaction is carried out at a temperature of 250-260℃ for 2.5-3.5 hours; the low-pressure reaction is carried out at a pressure of -50 to -80 kPa for 0.5-1 hours.

[0033] Furthermore, in step S3, the temperature of the twin-screw extruder is 220-250℃, and the pressure is -80~-90kPa.

[0034] The beneficial effects of this invention are as follows: This invention employs a combination of multiple bio-based monomers. Bio-based terephthalic acid and bio-based furanyl dicarboxylic acid provide rigid aromatic rings, while bio-based adipic acid is used to adjust the material's flexibility. Aromatic ring-containing diamines help improve the high-temperature resistance of the bio-based nylon material. Through the combined action of these monomers, a semi-aromatic-aliphatic alternating copolymer with excellent temperature resistance is formed. Specifically, by introducing monomers with aromatic ring structures, and adding nano-carbon fillers and aminated nano-boron nitride to form a thermally conductive / reinforcing network, the bio-based nylon acquires excellent high-temperature resistance, flame retardancy, and mechanical properties. The addition of compatibilizers improves the compatibility between the components and also helps to synergistically improve the mechanical properties of the bio-based nylon material. The combination of antioxidants and catalysts enhances the long-term anti-aging performance of the bio-based nylon material. The resulting bio-based nylon material exhibits good high-temperature resistance, mechanical properties, and flame retardancy, and has a high bio-based raw material content, conforming to the development trend of green and environmentally friendly materials. Detailed Implementation

[0035] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments. The content mentioned in the embodiments is not intended to limit the present invention.

[0036] In the following embodiments of the present invention, it should be noted that the bio-based adipic acid used in the embodiments is obtained by glucose fermentation, and the bio-based terephthalic acid and bio-based furanyl dicarboxylic acid are obtained by lignocellulose conversion. The present invention can increase the bio-based content of the bio-based nylon by using monomers from bio-based raw materials.

[0037] Example 1

[0038] This embodiment provides a high-temperature resistant bio-based nylon, comprising the following raw materials in parts by weight: 32 parts of bio-based adipic acid, 38 parts of bio-based terephthalic acid, 10 parts of bio-based furanyl dicarboxylic acid, 53 parts of aromatic ring-containing diamine, 2.5 parts of nano-carbon filler, 3.5 parts of compatibilizer, 0.8 parts of aminated nano-boron nitride, 0.8 parts of antioxidant, and 0.1 parts of catalyst.

[0039] Furthermore, the aromatic ring-containing diamine is a compound of p-phenylenediamine and 1,5-pentanediamine in a 1.9:1 ratio.

[0040] Furthermore, the nano-carbon filler is a graphene-multi-walled carbon nanotube hybrid filler, and the preparation method of the graphene-multi-walled carbon nanotube hybrid filler includes the following steps:

[0041] Step A1: Graphene oxide was dispersed in dimethylformamide at a mass-to-volume ratio of 1:200 and ultrasonically dispersed for 1 hour at an ultrasonic power of 300W. Then, 25wt% ethylenediamine was added, and the mixture was refluxed at 80°C for 24 hours. The resulting product was obtained by centrifugation, washing, and vacuum drying.

[0042] Step A2: Add multi-walled carbon nanotubes to a mixed acid solution at a mass-to-volume ratio of 1:100 and sonicate in an ice-water bath for 2 hours; obtain carboxylated multi-walled carbon nanotubes by centrifugation, washing, and vacuum drying.

[0043] Step A3: The amino-derived graphene obtained in step A1 and the carboxylated multi-walled carbon nanotubes obtained in step A2 are added to dimethylformamide at a mass ratio of 1.5:1 and ultrasonically dispersed for 30 min. Then, N,N'-dicyclohexylcarbodiimide and N-hydroxysuccinimide are added and mixed evenly. The mixture is heated at 60°C for 12 h under a nitrogen atmosphere. The product is centrifuged, washed and vacuum dried to obtain the graphene-multi-walled carbon nanotube hybrid filler.

[0044] Furthermore, in step A1, the average sheet diameter of the graphene oxide is 3 μm and the oxygen content is 25%.

[0045] Furthermore, in step A2, the average diameter of the multi-walled carbon nanotubes is 20 nm and the average length is 2 μm; the mixed acid solution is obtained by mixing sulfuric acid and nitric acid in a volume ratio of 3:1.

[0046] Furthermore, in step A3, the N,N'-dicyclohexylcarbodiimide accounts for 40% of the mass of the carboxylated carbon nanofiller, and the N-hydroxysuccinimide accounts for 19% of the mass of the carboxylated carbon nanofiller.

[0047] Furthermore, the compatibilizer is maleic anhydride and glycidyl methacrylate dimonomer-grafted nylon, and the preparation method of the maleic anhydride and glycidyl methacrylate dimonomer-grafted nylon includes the following steps:

[0048] Step B1: Place the grafted nylon matrix under vacuum drying at 80℃ for 12 hours, and control the moisture content to be below 0.05%.

[0049] Step B2: The grafted nylon matrix obtained in step B1, 3 wt% maleic anhydride, 0.5 wt% dicumyl peroxide and 0.16 wt% stabilizer are premixed at high speed and then added to a twin-screw extruder.

[0050] Step B3: Inject 4wt% glycidyl methacrylate, 0.13wt% tert-butyl peroxide, and 0.1wt% hydroquinone into the melting zone of the twin-screw extruder through the side feed port. Maintain the temperature of the reaction zone and react for 6 minutes. Extrude the strips, cool them with water, and granulate them to obtain the crude product.

[0051] Step B4: The crude product from step B3 is extracted with xylene using a Soxhlet extractor. The collected product is placed in methanol and stirred to precipitate. After filtration again, it is dried under vacuum to obtain the maleic anhydride and glycidyl methacrylate bis-monomer grafted nylon.

[0052] Furthermore, in step B1, the grafted nylon matrix is ​​nylon 610, and the stabilizer is a compound of antioxidant 1010 and phosphite 168 in a mass ratio of 2:1.

[0053] Furthermore, in step B2, the zone temperatures of the twin-screw extruder are specifically as follows: the feed zone temperature is 210°C, the melt zone temperature is 230°C, the reaction zone temperature is 235°C, the die head temperature is 220°C, the screw speed is 300 rpm, and the residence time is 2 min.

[0054] Furthermore, the antioxidant is a compound of antioxidant 1098 and antioxidant 168 in a mass ratio of 2:1.

[0055] Furthermore, the catalyst is sodium hypophosphite.

[0056] This invention also provides a method for preparing the above-mentioned high-temperature resistant bio-based nylon, comprising the following steps:

[0057] Step S1: Dissolve bio-based adipic acid, bio-based terephthalic acid and bio-based furanyl dicarboxylic acid in a mixed solvent of ethanol / water at 80°C. Then slowly add a solution containing an aromatic ring diamine to adjust the pH of the system to 7.8. After precipitating nylon salt, dry the solution.

[0058] Step S2: Add the nylon salt and catalyst obtained in step S1 to a high-pressure reactor for high-temperature reaction, followed by depressurization reaction to obtain the prepolymer, which is then pulverized for later use.

[0059] Step S3: The prepolymer obtained in step S2, the dehydrated and dried nano-carbon filler, compatibilizer and antioxidant are premixed evenly and fed into a twin-screw extruder for melt blending. Aminated nano-boron nitride is added through the side feed port of the melt zone. When the intrinsic viscosity of the polymer reaches 1.5 dL / g or higher, it is extruded and granulated, water-cooled, pelletized and dried to obtain the high-temperature resistant bio-based nylon.

[0060] Furthermore, in step S2, the high-temperature reaction is carried out at a temperature of 250°C for 3 hours; the low-pressure reaction is carried out at a pressure of -60 kPa for 1 hour.

[0061] Furthermore, in step S3, the zone temperatures of the twin-screw extruder are specifically as follows: the feed zone temperature is 210°C, the melting zone temperature is 230°C, the reaction zone temperature is 250°C, the die head temperature is 230°C, and the pressure is -80 kPa.

[0062] Example 2

[0063] This embodiment provides a high-temperature resistant bio-based nylon, comprising the following raw materials in parts by weight: 32 parts of bio-based adipic acid, 38 parts of bio-based terephthalic acid, 10 parts of bio-based furanyl dicarboxylic acid, 53 parts of aromatic ring-containing diamine, 2.8 parts of nano-carbon filler, 4 parts of compatibilizer, 1 part of aminated nano-boron nitride, 1 part of antioxidant, and 0.1 parts of catalyst.

[0064] Furthermore, the aromatic ring-containing diamine is a compound of p-phenylenediamine and 1,5-pentanediamine in a 2:1 ratio.

[0065] Furthermore, the nano-carbon filler is aminated graphene, and the preparation method of the aminated graphene is consistent with step A1 in Example 1.

[0066] Furthermore, the compatibilizer is maleic anhydride-grafted nylon, and the preparation method of the maleic anhydride includes the following steps: placing the grafted nylon matrix under vacuum drying at 85℃ for 12 hours, controlling the water content to be below 0.05%; feeding the grafted nylon matrix, 3.2wt% maleic anhydride, 0.5wt% dicumyl peroxide, and 0.18wt% stabilizer into a twin-screw extruder for extrusion granulation at high speed; performing Soxhlet extraction on the crude product with xylene; collecting the product and placing it in methanol for stirring and precipitation; filtering again and then vacuum drying to obtain the maleic anhydride-grafted nylon. The grafted nylon matrix is ​​nylon 66, and the specific zone temperatures of the twin-screw extruder are: feed zone temperature 220℃, melt zone temperature 230℃, reaction zone temperature 245℃, die head temperature 230℃, screw speed 300rpm, and residence time 2min.

[0067] Furthermore, the antioxidant is a compound of antioxidant 1098 and antioxidant 168 in a mass ratio of 2:1.

[0068] Furthermore, the catalyst is sodium hypophosphite.

[0069] The preparation method of bio-based nylon in this embodiment is the same as that in Example 1, and will not be repeated here.

[0070] Example 3

[0071] This embodiment provides a high-temperature resistant bio-based nylon, comprising the following raw materials in parts by weight: 32 parts of bio-based adipic acid, 38 parts of bio-based terephthalic acid, 10 parts of bio-based furanyl dicarboxylic acid, 53 parts of aromatic ring-containing diamine, 2 parts of nano-carbon filler, 3 parts of compatibilizer, 0.7 parts of aminated nano-boron nitride, 0.8 parts of antioxidant, and 0.08 parts of catalyst.

[0072] Furthermore, the aromatic ring-containing diamine is a compound of p-phenylenediamine and 1,5-pentanediamine in a 2.3:1 ratio.

[0073] Furthermore, the nano-carbon filler is a carboxylated multi-walled carbon nanotube, and the preparation method of the carboxylated multi-walled carbon nanotube is the same as step A2 in Example 1.

[0074] Furthermore, the compatibilizer is glycidyl methacrylate-grafted nylon, and the preparation method of the glycidyl methacrylate-grafted nylon includes the following steps: placing the grafted nylon matrix under vacuum drying at 80℃ for 14h, controlling the water content to be below 0.05%; adding 3.8wt% glycidyl methacrylate, 0.15wt% tert-butyl peroxide, and 0.15wt% hydroquinone premixed into a twin-screw extruder, extruding and granulating, extracting the crude product with xylene using a Soxhlet extractor, collecting the product and placing it in methanol for stirring and precipitation, filtering again, and then vacuum drying to obtain the glycidyl methacrylate-grafted nylon. The grafted nylon matrix is ​​nylon 610, and the specific zone temperatures of the twin-screw extruder are: feed zone temperature 210℃, melt zone temperature 220℃, reaction zone temperature 230℃, die head temperature 220℃, screw speed 200rpm, and residence time 2min.

[0075] Furthermore, the antioxidant is a compound of antioxidant 1098 and antioxidant 168 in a mass ratio of 2:1.

[0076] Furthermore, the catalyst is sodium hypophosphite.

[0077] The preparation method of bio-based nylon in this embodiment is the same as that in Example 1, and will not be repeated here.

[0078] Example 4

[0079] This embodiment provides a high-temperature resistant bio-based nylon, comprising the following raw materials in parts by weight: 30 parts of bio-based adipic acid, 36 parts of bio-based terephthalic acid, 8 parts of bio-based furanyl dicarboxylic acid, 50 parts of aromatic ring-containing diamine, 2.2 parts of nano-carbon filler, 3 parts of compatibilizer, 0.6 parts of aminated nano-boron nitride, 0.7 parts of antioxidant, and 0.08 parts of catalyst.

[0080] Furthermore, the aromatic ring-containing diamine is a compound of p-phenylenediamine and 1,5-pentanediamine in a 2:1 ratio.

[0081] Furthermore, the nano-carbon filler is a graphene-multi-walled carbon nanotube hybrid filler, and the preparation method of the graphene-multi-walled carbon nanotube hybrid filler includes the following steps:

[0082] Step A1: Graphene oxide was dispersed in dimethylformamide at a mass-to-volume ratio of 1:200 and ultrasonically dispersed for 1 hour at an ultrasonic power of 300W. Then, 25wt% ethylenediamine was added, and the mixture was refluxed at 80°C for 24 hours. The resulting product was obtained by centrifugation, washing, and vacuum drying.

[0083] Step A2: Add multi-walled carbon nanotubes to a mixed acid solution at a mass-to-volume ratio of 1:100 and sonicate in an ice-water bath for 2 hours; obtain carboxylated multi-walled carbon nanotubes by centrifugation, washing, and vacuum drying.

[0084] Step A3: The amino graphene obtained in step A1 and the carboxylated multi-walled carbon nanotubes obtained in step A2 are added to dimethylformamide at a mass ratio of 1.5:1 and ultrasonically dispersed for 30 min. Then, N,N'-dicyclohexylcarbodiimide and N-hydroxysuccinimide are added and mixed evenly. The mixture is heated at 60°C for 12 h under a nitrogen atmosphere. The product is centrifuged, washed and vacuum dried to obtain the graphene-multi-walled carbon nanotube hybrid filler.

[0085] Step A4: The graphene-multi-walled carbon nanotube hybrid filler obtained in step A3 is mixed with ε-caprolactam, sodium hypophosphite and deionized water and placed in a reaction vessel. The mixture is first reacted at 120℃ and 0.2MPa for 1 h, then at 160℃ and 0.5MPa for 2 h, and then at 220℃ and -0.1MPa for 0.5 h. The product is extracted with boiling water for 24 h and then dried under vacuum to obtain the grafted graphene-multi-walled carbon nanotube hybrid filler.

[0086] Furthermore, in step A1, the average sheet diameter of the graphene oxide is 3 μm and the oxygen content is 25%.

[0087] Furthermore, in step A2, the multi-walled carbon nanotubes have an average diameter of 20 nm and a length of 2 μm; the mixed acid solution is obtained by mixing sulfuric acid and nitric acid in a volume ratio of 3:1.

[0088] Furthermore, in step A3, the N,N'-dicyclohexylcarbodiimide is 40% of the mass of the carboxylated multi-walled carbon nanotubes, and the N-hydroxysuccinimide is 19% of the mass of the carboxylated multi-walled carbon nanotubes.

[0089] Furthermore, in step A4, the mass ratio of the graphene-multi-walled carbon nanotube hybrid filler, ε-caprolactam, and deionized water is 1:9:1, and the amount of sodium hypophosphite used is 0.5 wt% of the graphene-multi-walled carbon nanotube hybrid filler.

[0090] Furthermore, the compatibilizer is glycidyl methacrylate dimonomer-grafted nylon, and the preparation method of the maleic anhydride and glycidyl methacrylate dimonomer-grafted nylon includes the following steps:

[0091] Step B1: Place the grafted nylon matrix under vacuum drying at 80℃ for 12 hours, and control the moisture content to be below 0.05%.

[0092] Step B2: The grafted nylon matrix obtained in step B1, 3.2 wt% maleic anhydride, 0.5 wt% dicumyl peroxide and 0.16 wt% stabilizer are premixed at high speed and then added to a twin-screw extruder.

[0093] Step B3: Inject 4.5wt% glycidyl methacrylate, 0.15wt% tert-butyl peroxide, and 0.15wt% hydroquinone into the melting zone of the twin-screw extruder through the side feed port. Maintain the temperature of the reaction zone and react for 7 minutes. Extrude the strips, cool them with water, and granulate them to obtain the crude product.

[0094] Step B4: The crude product from step B3 is extracted with xylene using a Soxhlet extractor. The collected product is placed in methanol and stirred to precipitate. After filtration again, it is dried under vacuum to obtain the maleic anhydride and glycidyl methacrylate bis-monomer grafted nylon.

[0095] Furthermore, in step B1, the grafted nylon matrix is ​​nylon 66.

[0096] Furthermore, in step B2, the zone temperatures of the twin-screw extruder are specifically as follows: the feed zone temperature is 220°C, the melt zone temperature is 240°C, the reaction zone temperature is 250°C, the die head temperature is 230°C, the screw speed is 200 rpm, and the residence time is 2 min.

[0097] Furthermore, the antioxidant is a compound of antioxidant 1098 and antioxidant 168 in a mass ratio of 2:1.

[0098] Furthermore, the catalyst is sodium hypophosphite.

[0099] Example 5

[0100] This embodiment provides a high-temperature resistant bio-based nylon, comprising the following raw materials in parts by weight: 30 parts of bio-based adipic acid, 34 parts of bio-based terephthalic acid, 9 parts of bio-based furanyl dicarboxylic acid, 49 parts of aromatic ring-containing diamine, 2.2 parts of nano-carbon filler, 2.8 parts of compatibilizer, 1 part of aminated nano-boron nitride, 0.8 parts of antioxidant, and 0.06 parts of catalyst.

[0101] Furthermore, the aromatic ring-containing diamine is a compound of p-phenylenediamine and 1,5-pentanediamine in a 2:1 ratio.

[0102] Furthermore, the nano-carbon filler is aminated graphene, and the preparation method of the aminated graphene is consistent with step A1 of Example 1.

[0103] Furthermore, the compatibilizer is maleic anhydride and glycidyl methacrylate dimonomer grafted nylon, and the preparation method of the maleic anhydride and glycidyl methacrylate dimonomer grafted nylon is the same as in Example 1.

[0104] Furthermore, the antioxidant is a compound of antioxidant 1098 and antioxidant 168 in a mass ratio of 2:1.

[0105] Furthermore, the catalyst is sodium hypophosphite.

[0106] Example 6

[0107] This embodiment provides a high-temperature resistant bio-based nylon, comprising the following raw materials in parts by weight: 32 parts of bio-based adipic acid, 36 parts of bio-based terephthalic acid, 9 parts of bio-based furanyl dicarboxylic acid, 52 parts of aromatic ring-containing diamine, 2 parts of nano-carbon filler, 3 parts of compatibilizer, 0.6 parts of aminated nano-boron nitride, 0.8 parts of antioxidant, and 0.07 parts of catalyst.

[0108] Furthermore, the aromatic ring-containing diamine is a compound of m-phenylenediamine and 1,5-pentanediamine in a 2:1 ratio.

[0109] Furthermore, the nano-carbon filler is a carboxylated multi-walled carbon nanotube, and the preparation method of the carboxylated multi-walled carbon nanotube is the same as step A1 in Example 1.

[0110] Furthermore, the compatibilizer is maleic anhydride and glycidyl methacrylate dimonomer grafted nylon, and the preparation method of the maleic anhydride and glycidyl methacrylate dimonomer grafted nylon is the same as in Example 1.

[0111] Furthermore, the antioxidant is a compound of antioxidant 1098 and antioxidant 168 in a mass ratio of 2:1.

[0112] Furthermore, the catalyst is sodium hypophosphite.

[0113] Comparative Example 1

[0114] The difference between this comparative example and Example 1 is that this comparative example is a high-temperature resistant bio-based nylon, comprising the following raw materials in parts by weight: 32 parts of bio-based adipic acid, 48.5 parts of bio-based terephthalic acid, 53 parts of 1,5-pentanediamine, 2.5 parts of nano-carbon filler, 3.5 parts of compatibilizer, 0.8 parts of aminated nano-boron nitride, 0.8 parts of antioxidant, and 0.1 parts of catalyst; the rest of the contents of this comparative example are the same as those of Example 1.

[0115] Comparative Example 2

[0116] The difference between this comparative example and Comparative Example 1 is that this comparative example did not add 0.8 parts of aminated nano boron nitride, while the remaining components were varied proportionally. The rest of the contents of this comparative example are the same as in Example 1.

[0117] Comparative Example 3

[0118] The difference between this comparative example and Comparative Example 1 is that this comparative example uses an equal amount of maleic anhydride polyethylene to replace the compatibilizer in Example 1, and uses an equal amount of commercially available graphene oxide to replace the nano-carbon filler in Example 1.

[0119] This invention involves performance testing of the high-temperature resistant bio-based nylons prepared in Examples 1-6 and Comparative Examples 1-3. Tensile strength and elongation at break were tested using ISO 527-2; simply supported beam impact strength was tested using ISO 1179-1; flame retardancy rating was tested using UL 94; and melting temperature was tested using the DSC method: the temperature was increased from room temperature to 250°C at a rate of 10°C / min, held for 5 minutes, cooled to 30°C, and then increased again to 250°C at the same rate. The second heating curve was analyzed, and the temperature corresponding to the highest point of the endothermic peak was taken as the melting temperature. Specific test results are shown in the table below.

[0120]

[0121] As shown in the table above, the high-temperature resistant bio-based nylons prepared through Examples 1-6 possess high mechanical properties, with melting temperatures all above 235°C, and maintain good flame retardancy without the addition of flame retardants. This invention utilizes the co-reaction of bio-based adipic acid, bio-based terephthalic acid, and bio-based furanyl dicarboxylic acid with various monomers, including aromatic ring-containing diamines, to form a semi-aromatic-aliphatic alternating copolymer with excellent temperature resistance. By controlling the ratio of aromatic rings to aliphatic segments, the temperature resistance of the bio-based nylon material is significantly improved while maintaining its mechanical properties, enabling long-term use in high-temperature environments. Furthermore, the synergistic effect of the aromatic ring structure, nano-carbon fillers, and aminated nano-boron nitride forms a thermally conductive / reinforcing network, coupled with the interface-improving effect of compatibilizers, further significantly enhancing the temperature resistance and mechanical properties of this bio-based nylon.

[0122] The specific embodiments described above are further illustrations of the technical solution and beneficial effects of the present invention, and are not intended to limit the implementation methods. For those skilled in the art, any obvious substitutions without departing from the concept of the present invention are within the protection scope of the present invention.

Claims

1. A high temperature resistant bio-based nylon, characterized in that: The raw materials include the following parts by weight: 28-35 parts of bio-based adipic acid, 35-40 parts of bio-based terephthalic acid, 8-10 parts of bio-based furanyl dicarboxylic acid, 50-55 parts of aromatic ring-containing diamine, 1.5-3 parts of nano-carbon filler, 2-4 parts of compatibilizer, 0.5-1.2 parts of aminated nano-boron nitride, 0.3-1.0 parts of antioxidant, and 0.05-0.12 parts of catalyst; The aromatic ring-containing diamine is composed of p-phenylenediamine and 1,5-pentanediamine in a mass ratio of 1.8-2.5:1; The compatibilizer is at least one of maleic anhydride-grafted nylon, glycidyl methacrylate-grafted nylon, and maleic anhydride and glycidyl methacrylate dimonomer-grafted nylon. The nano-carbon filler is selected from at least one of the following three categories: (i) Aminographene, wherein the preparation method of the aminographene is as follows: dispersing graphene oxide in dimethylformamide by ultrasonic dispersion, then adding 20-30wt% ethylenediamine, refluxing under heating conditions for 8-12h, and obtaining aminographene by centrifugation, washing and vacuum drying. (ii) Carboxylated multi-walled carbon nanotubes, wherein the preparation method of the carboxylated multi-walled carbon nanotubes is as follows: multi-walled carbon nanotubes are added to a mixed acid solution and ultrasonically treated, and then centrifuged, washed and vacuum dried to obtain carboxylated multi-walled carbon nanotubes; (iii) Graphene-multi-walled carbon nanotube hybrid filler, wherein the preparation method of the graphene-multi-walled carbon nanotube hybrid filler is as follows: (i) amino-graphene and (ii) carboxylated multi-walled carbon nanotubes are added to dimethylformamide at a mass ratio of 1-2:1 and ultrasonically dispersed. Then, N,N'-dicyclohexylcarbodiimide and N-hydroxysuccinimide are added and mixed evenly. The mixture is heated and reacted under a nitrogen atmosphere for 10-12 hours. The product is centrifuged, washed and vacuum dried to obtain the graphene-multi-walled carbon nanotube hybrid filler.

2. The high-temperature resistant bio-based nylon according to claim 1, characterized in that: The antioxidant is at least one of hindered phenolic antioxidants, phosphite antioxidants, and hindered amine antioxidants.

3. The high-temperature resistant bio-based nylon according to claim 1, characterized in that: The catalyst is at least one of phosphoric acid, phosphorous acid, hypophosphorous acid, and sodium hypophosphite.

4. The method for preparing high-temperature resistant bio-based nylon according to any one of claims 1-3, characterized in that: Includes the following steps: Step S1: Dissolve bio-based adipic acid, bio-based terephthalic acid and bio-based furanyl dicarboxylic acid in a mixed solvent of ethanol / water by heating. Then slowly add a solution containing an aromatic ring diamine to adjust the pH of the system to 7-8. After precipitating nylon salt, dry the solution. Step S2: Add the nylon salt and catalyst obtained in step S1 to a high-pressure reactor for high-temperature reaction, followed by depressurization reaction to obtain the prepolymer, which is then pulverized for later use. Step S3: The prepolymer obtained in step S2, the dehydrated and dried nano-carbon filler, compatibilizer and antioxidant are premixed evenly and fed into a twin-screw extruder for melt blending. Aminated nano-boron nitride is added through the side feed port of the melt zone. When the intrinsic viscosity of the polymer reaches 1.5 dL / g or higher, it is extruded and granulated, water-cooled, pelletized and dried to obtain the high-temperature resistant bio-based nylon.

5. The method for preparing high-temperature resistant bio-based nylon according to claim 4, characterized in that: In step S2, the high-temperature reaction is carried out at a temperature of 250-260℃ for 2.5-3.5 hours; the low-pressure reaction is carried out at a pressure of -50 to -80 kPa for 0.5-1 hours.

6. The method for preparing high-temperature resistant bio-based nylon according to claim 4, characterized in that: In step S3, the temperature of the twin-screw extruder is 220-250℃ and the pressure is -80 ~ -90kPa.

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