A low-cost, high-toughness nylon and its preparation method

Abstract

The present invention relates to the technical field of nylon materials, and in particular to a kind of low-cost high-toughness nylon and preparation method thereof, the nylon is made up of the raw materials of following parts by weight: 80-120 parts of resins, 200-400 parts of water, 1-2 parts of monoamines, 0.3-0.8 parts of toughening agents, 20-30 parts of fillers, 5-10 parts of composite nanofibers, 0.1-0.3 parts of fatty acid salt nucleating agents, 1-2 parts of antioxidants, 1-2 parts of pigments, 0.1-0.5 parts of catalysts. In the present invention, by adding to nylon after being pre-treated by specially made composite nanofibers, the network structure with high stability formed by mutual cross-linking in nylon can be better transmitted and dispersed external force, the energy of external force is consumed and dispersed, and network structure is separated under external force, more energy needs to be consumed, and crack needs to bypass network structure when expanding, further consumes crack propagation energy, so that nylon has better toughness strength, can meet the requirement of high toughness under the premise of using a small amount of toughening agent.

Description

Technical Field

[0001] The present invention relates to the technical field of nylon materials, in particular to low-cost high-toughness nylon and a preparation method thereof. Background Art

[0002] Nylon, one of the earliest developed engineering plastics, is widely used in the chemical, electrical, automotive, and other machinery manufacturing sectors due to its high strength, high modulus, excellent chemical and wear resistance, high melting point, and low coefficient of friction. However, in more demanding applications and further research, nylon exhibits brittleness at low temperatures and in a dry state, significantly limiting its application. For example, traditional nylon 66, nylon 610, and nylon 612 have high crystallinity. While they maintain mechanical strength at low temperatures and in a dry state, they exhibit significant brittleness, necessitating the addition of large amounts of toughening agents to adjust their toughness.

[0003] The invention patent with publication number CN103965467A discloses a tough nylon and a preparation method thereof. By utilizing the copolymerization method and the structural characteristics of aliphatic diacid monomers, aliphatic diamine monomers and alicyclic diamine monomers, a tough nylon material is prepared by copolymerizing aliphatic diacids with aliphatic diamines and / or alicyclic diamines with amide salts, etc. Due to the increase in the molecular chain unit length of the tough nylon, the tough nylon material of the present invention has significantly increased toughness compared with traditional nylon; however, since the spatial arrangement of the nylon molecular chain is changed in this technical solution, the spatial crystallization behavior of the nylon is reduced. As a result, although the nylon material has good toughness, its melting point is lowered, resulting in a significant decrease in the thermal stability of the nylon, which reduces the application range of the nylon and makes it unusable in some special fields under high-temperature environments, resulting in the inability to promote nylon on a large scale. Summary of the Invention

[0004] In view of the problems existing in the prior art, the object of the present invention is to provide a low-cost, high-toughness nylon and a preparation method thereof.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] Disclosed is a low-cost, high-toughness nylon, which is prepared from the following raw materials in parts by weight: 80-120 parts of resin, 200-400 parts of water, 1-2 parts of monoamine, 0.3-0.8 parts of toughening agent, 20-30 parts of filler, 5-10 parts of composite nanofibers, 0.1-0.3 parts of fatty acid salt nucleating agent, 1-2 parts of antioxidant, 1-2 parts of pigment, and 0.1-0.5 parts of catalyst.

[0007] As a further preferred embodiment of the present invention, the resin is composed of polydodecanediamine and polycaprolactam in a mass ratio of (10-12):1;

[0008] The monoamine is any one of aliphatic monoamine, alicyclic monoamine, and aromatic monoamine;

[0009] The toughening agent is maleic anhydride grafted polyolefin elastomer;

[0010] The filler is composed of barium sulfate, titanium dioxide, and kaolin in a mass ratio of (2-3):1:(1-2);

[0011] The antioxidant is composed of antioxidant 168 and antioxidant 1098 of equal mass;

[0012] The catalyst is any one of sodium hypophosphite and phosphorous acid.

[0013] As a further preferred embodiment of the present invention, the preparation method of the composite nanofiber is as follows:

[0014] 1) adding silicon carbide nanofibers to toluene, ultrasonically dispersing for 10-20 minutes, then continuously introducing inert gas for 5-10 minutes with continuous stirring, then transferring to an oil bath, adding 3-aminopropyltriethoxysilane, and reacting at 150-160° C. for 6-8 hours. After the reaction is complete, the product is filtered, repeatedly washed, and then dried to obtain pretreated nanofibers;

[0015] 2) Weigh an appropriate amount of pretreated nanofibers, add deionized water, anhydrous ethanol and ammonia water, ultrasonically treat for 30-50 minutes, add resorcinol, stir thoroughly, add formaldehyde solution and continue stirring for 20-25 hours, then wash the product repeatedly with deionized water and anhydrous ethanol and dry it, transfer it to a tube furnace, keep it at 600-650°C for 5-8 hours under a nitrogen atmosphere, cool it naturally, immerse it in a concentrated acid solution, stir it at 200-300 r / min for 3-6 hours, filter it, wash it repeatedly, and dry it to obtain composite nanofibers.

[0016] As a further preferred embodiment of the present invention, in step 1), the ratio of the amount of the silicon carbide nanofiber, toluene, and 3-aminopropyltriethoxysilane is (1-3) g: (150-260) mL: (0.3-0.8) g;

[0017] The rotation speed of the continuous stirring is 300-500 r / min.

[0018] As a further preferred embodiment of the present invention, in step 2), the ratio of the amount of the pretreated nanofibers, deionized water, anhydrous ethanol, ammonia water, resorcinol, and formaldehyde solution is (0.1-0.5) g: (80-120) mL: (32-38) mL: (0.4-0.8) mL: (0.6-1.0) g: (1.0-1.6) mL;

[0019] The concentration of the formaldehyde solution is 38-40wt%;

[0020] The continuous stirring speed is 150-200 r / min;

[0021] The concentrated acid solution is composed of concentrated nitric acid and concentrated sulfuric acid in a volume ratio of 1:(3.0-3.5).

[0022] A method for preparing low-cost high-toughness nylon specifically comprises the following steps:

[0023] 1) adding resin, water, monoamine, antioxidant and catalyst into a reaction kettle according to parts by weight and mixing evenly, heating to 190-210° C., polymerizing at a pressure of 1.2-1.8 MPa for 3-7 hours, then slowly reducing the pressure to normal pressure, while raising the system temperature to 260-275° C., and continuing the reaction at a vacuum degree of 30-100 Pa for 3-7 hours to prepare a nylon substrate;

[0024] 2) The pretreated composite nanofibers are put into a low-speed mixer together with a nylon substrate, a toughening agent, a filler, a fatty acid salt nucleating agent, and a pigment, and mixed for 5-10 minutes to obtain a blended material, which is then put into a twin-screw extruder. After mixing, the mixture is melt-extruded, cooled, and pelletized and sieved to obtain the desired high-toughness nylon.

[0025] As a further preferred embodiment of the present invention, the temperature of the twin-screw extruder is 230-260° C. and the rotation speed is 300-400 r / min.

[0026] As a further preferred embodiment of the present invention, the pretreatment process of the composite nanofiber is as follows:

[0027] 1) dissolving molybdenum trioxide, thioacetamide, and urea in a mixed solution of deionized water and anhydrous ethanol, stirring thoroughly to obtain a reaction solution, then adding the composite nanofibers to the reaction solution, ultrasonically dispersing for 20-30 minutes, transferring the mixture to a reactor, and keeping the mixture at 200-230° C. for 18-23 hours. After the reaction is completed, the mixture is repeatedly washed with deionized water and anhydrous ethanol, dried, and transferred to a tube furnace, kept at 600-630° C. for 2-5 hours under an argon atmosphere, and cooled naturally in the furnace for later use;

[0028] 2) At room temperature, zinc nitrate hexahydrate is added to anhydrous ethanol, stirred to dissolve, and then 2-methylimidazole is added. After thorough stirring, the above-mentioned standby product is added. After ultrasonic dispersion for 10-20 minutes, the mixture is transferred to a hydrothermal reactor, sealed, and reacted at 60-70°C for 1-3 hours. After the reaction is completed, the mixture is cooled to room temperature, repeatedly rinsed with anhydrous toluene, and then dried.

[0029] As a further preferred embodiment of the present invention, in step 1), the usage ratio of molybdenum trioxide, thioacetamide, urea, deionized water, anhydrous ethanol, and composite nanofibers is (50-80) mg: (0.1-0.3) g: (1-2) g: (30-50) mL: (30-50) mL: (2-5) g.

[0030] As a further preferred embodiment of the present invention, in step 2), the usage ratio of the zinc nitrate hexahydrate, anhydrous ethanol, 2-methylimidazole, and the standby product is (1-3) g: (100-150) mL: (3-8) g: (5-10) g.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] In the present invention, hydrophilic groups are grafted onto the surface of silicon carbide nanofibers by a silane coupling agent to reduce the agglomeration of silicon carbide nanofibers, and phenolic resin is coated on the surface of silicon carbide nanofibers by in-situ polymerization. Then, the phenolic resin layer is carbonized into a carbon layer under a nitrogen atmosphere, and acid etching with concentrated acid can effectively increase the roughness of the carbon layer, thereby increasing the contact area between the nanofibers and improving the mutual bonding strength, so that the network structure formed by the cross-linking of the nanofibers is more stable, and can better transmit and disperse external forces, consume and disperse the energy of the external forces, so that the nylon has better toughness and strength; at the same time, in order to further improve the toughness and strength of nylon, the present invention also pre-treats the composite nanofibers, uses the composite nanofibers as a deposition matrix, uses molybdenum trioxide and thioacetamide as molybdenum sources and sulfur sources, and forms a nanosheet array on the deposition matrix by a hydrothermal method. The deposited nanosheets have a larger contact area, which further improves the bonding strength between the nanofibers. At the same time, zinc nitrate and 2-methylimidazole are used as raw materials to deposit nanoparticles on the surface of the nanosheet array through hydrothermal reaction. The deposited nanoparticles increase the roughness of the nanosheets and increase the bonding strength between the two, so that more energy is required to separate the nanosheets, thereby enhancing the toughness. Moreover, since the strength of the nanosheets increases after stacking, the cracks need to bypass the nanosheets when expanding, thereby further consuming the crack expansion energy, thereby further enhancing the toughness; and since the deposited nanoparticles have a larger porosity and a larger specific surface area, they have abundant adsorption sites, which makes the bonding strength between the nanoparticles greater, making the nanosheets more difficult to separate, thereby significantly increasing the energy required to separate the nanosheets, and thus making the nylon have high toughness properties.

[0033] In the present invention, specially prepared composite nanofibers are pre-treated and then added to nylon, so that a highly stable network structure can be formed by cross-linking in the nylon, which can better transmit and disperse external forces, consume and disperse the energy of the external forces, and when the network structure is separated by an external force, more energy needs to be consumed, and the crack needs to bypass the network structure when expanding, which further consumes the crack expansion energy, thereby making the nylon have better toughness strength and can meet the high toughness requirements under the premise of using a small amount of toughening agent. DETAILED DESCRIPTION

[0034] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0035] In an embodiment of the present invention, the resin is composed of polydodecanediamine and polycaprolactam in a mass ratio of 10:1, the monoamine is octylamine (aliphatic monoamine), the toughening agent is maleic anhydride grafted polyolefin elastomer (POE-g-MAH, granular), the filler is composed of barium sulfate, titanium dioxide, and kaolin in a mass ratio of 2:1:1.5, the fatty acid salt nucleating agent is calcium stearate, the antioxidant is composed of equal masses of antioxidant 168 and antioxidant 1098, and the catalyst is sodium hypophosphite.

[0036] Example 1

[0037] A low-cost, high-toughness nylon is prepared from the following raw materials in parts by weight: 80 parts of resin, 200 parts of water, 1 part of monoamine, 0.3 parts of toughening agent, 20 parts of filler, 5 parts of composite nanofibers, 0.1 parts of fatty acid salt nucleating agent, 1 part of antioxidant, 1 part of pigment, and 0.1 parts of catalyst;

[0038] The preparation method of the low-cost high-toughness nylon specifically comprises the following steps:

[0039] 1) adding resin, water, monoamine, antioxidant and catalyst into a reaction kettle according to parts by weight, mixing uniformly, heating to 190° C., polymerizing under a pressure of 1.2 MPa for 3 hours, then slowly reducing the pressure to normal pressure, while raising the system temperature to 260° C., and continuing the reaction under a vacuum degree of 30 Pa for 3 hours to prepare a nylon substrate;

[0040] 2) The pretreated composite nanofibers are placed in a low-speed mixer together with a nylon substrate, a toughening agent, a filler, a fatty acid salt nucleating agent, and a pigment, and mixed for 5 minutes to obtain a blended material, which is then placed in a twin-screw extruder, mixed and melt-extruded at a temperature of 230° C. and a speed of 300 r / min. After cooling, pelletizing and screening are performed to obtain the desired high-toughness nylon;

[0041] The pretreatment process of the composite nanofiber is as follows:

[0042] 50 mg of molybdenum trioxide, 0.1 g of thioacetamide, and 1 g of urea were dissolved in a mixed solution of 30 mL of deionized water and 30 mL of anhydrous ethanol, and the mixture was thoroughly stirred to obtain a reaction solution. 2 g of the composite nanofibers were then added to the reaction solution, ultrasonically dispersed at 200 W for 20 min, and then transferred to a reactor and kept at 200° C. for 18 h. After the reaction, the mixture was repeatedly washed with deionized water and anhydrous ethanol, dried, and transferred to a tube furnace. The mixture was kept at 600° C. for 2 h under an argon atmosphere, cooled naturally in the furnace, and then set aside.

[0043] At room temperature, add 1g of zinc nitrate hexahydrate to 100mL of anhydrous ethanol, stir to dissolve, then add 3g of 2-methylimidazole, stir thoroughly, add 5g of the above-mentioned spare product, ultrasonically disperse at 200W for 10min, transfer to a hydrothermal reactor, seal and react at 60°C for 1h, cool to room temperature after the reaction is completed, repeatedly wash with anhydrous toluene and dry.

[0044] The preparation method of the composite nanofiber is as follows:

[0045] 1) 1 g of silicon carbide nanofibers was added to 150 mL of toluene and ultrasonically dispersed at 200 W for 10 min. An inert gas was then introduced for 5 min and the mixture was stirred at 300 rpm. The mixture was then transferred to an oil bath and 0.3 g of 3-aminopropyltriethoxysilane was added. The mixture was reacted at 150° C. for 6 h. After the reaction was completed, the product was filtered, washed repeatedly, and dried to obtain pretreated nanofibers.

[0046] 2) Weigh 0.1 g of pretreated nanofibers, add 80 mL of deionized water, 32 mL of anhydrous ethanol and 0.4 mL of ammonia water, and after 200 W ultrasonic treatment for 30 min, add 0.6 g of resorcinol, stir thoroughly, add 1 mL of 38 wt% formaldehyde solution, and continue stirring at 150 r / min for 20 h. Then, the product is repeatedly washed with deionized water and anhydrous ethanol and dried, transferred to a tube furnace, kept warm at 600 ° C for 5 h under a nitrogen atmosphere, and immersed in a concentrated acid solution composed of concentrated nitric acid and concentrated sulfuric acid in a volume ratio of 1:3 after natural cooling. Stir at 200 r / min for 3 h, filter, wash repeatedly, and dry to obtain composite nanofibers.

[0047] Example 2

[0048] A low-cost, high-toughness nylon is prepared from the following raw materials in parts by weight: 100 parts of resin, 300 parts of water, 1.5 parts of monoamine, 0.5 parts of toughening agent, 25 parts of filler, 7 parts of composite nanofiber, 0.2 parts of fatty acid salt nucleating agent, 1.5 parts of antioxidant, 1.5 parts of pigment, and 0.3 parts of catalyst;

[0049] The preparation method of the low-cost high-toughness nylon specifically comprises the following steps:

[0050] 1) adding resin, water, monoamine, antioxidant and catalyst into a reaction kettle according to parts by weight and mixing uniformly, heating to 200° C., polymerizing under a pressure of 1.5 MPa for 5 hours, then slowly reducing the pressure to normal pressure, while raising the system temperature to 270° C., and continuing the reaction under a vacuum degree of 80 Pa for 5 hours to prepare a nylon substrate;

[0051] 2) The pretreated composite nanofibers are placed in a low-speed mixer together with a nylon substrate, a toughening agent, a filler, a fatty acid salt nucleating agent, and a pigment, and mixed for 8 minutes to obtain a blended material, which is then placed in a twin-screw extruder, mixed and melt-extruded at a temperature of 245° C. and a speed of 350 r / min. After cooling, pelletizing and screening are performed to obtain the desired high-toughness nylon;

[0052] The pretreatment process of the composite nanofiber is as follows:

[0053] 70 mg of molybdenum trioxide, 0.2 g of thioacetamide, and 1.5 g of urea were dissolved in a mixed solution of 40 mL of deionized water and 40 mL of anhydrous ethanol, and the mixture was thoroughly stirred to obtain a reaction solution. 3 g of the composite nanofibers were then added to the reaction solution, ultrasonically dispersed at 250 W for 25 min, and then transferred to a reactor and kept at 220° C. for 20 h. After the reaction, the mixture was repeatedly washed with deionized water and anhydrous ethanol, dried, and transferred to a tube furnace, kept at 620° C. for 3 h under an argon atmosphere, and naturally cooled with the furnace for later use.

[0054] At room temperature, add 2g of zinc nitrate hexahydrate to 130mL of anhydrous ethanol, stir to dissolve, then add 5g of 2-methylimidazole, stir thoroughly, add 8g of the above-mentioned spare product, and ultrasonically disperse at 250W for 15min. Then transfer to a hydrothermal reactor, seal it, and react at 65°C for 2h. After the reaction is completed, cool to room temperature, wash repeatedly with anhydrous toluene, and dry it.

[0055] The preparation method of the composite nanofiber is as follows:

[0056] 1) 2 g of silicon carbide nanofibers were added to 200 mL of toluene and ultrasonically dispersed at 250 W for 15 min. An inert gas was then continuously introduced for 8 min, and the mixture was continuously stirred at 400 rpm. The mixture was then transferred to an oil bath, 0.5 g of 3-aminopropyltriethoxysilane was added, and the mixture was reacted at 155° C. for 7 h. After the reaction was completed, the product was filtered, repeatedly washed, and dried to obtain pretreated nanofibers.

[0057] 2) Weigh 0.3 g of pretreated nanofibers, add 100 mL of deionized water, 35 mL of anhydrous ethanol and 0.6 mL of ammonia water, and after 250 W ultrasonic treatment for 40 min, add 0.8 g of resorcinol, stir thoroughly, add 1.5 mL of 38 wt% formaldehyde solution, and continue stirring at 200 r / min for 24 h. Then, the product is repeatedly washed with deionized water and anhydrous ethanol and dried, transferred to a tube furnace, kept warm at 630 ° C for 6 h under a nitrogen atmosphere, and immersed in a concentrated acid solution composed of concentrated nitric acid and concentrated sulfuric acid in a volume ratio of 1:3.2 after natural cooling. Stir at 250 r / min for 5 h, filter, wash repeatedly, and dry to obtain composite nanofibers.

[0058] Example 3

[0059] A low-cost, high-toughness nylon is prepared from the following raw materials in parts by weight: 120 parts of resin, 400 parts of water, 2 parts of monoamine, 0.8 parts of toughening agent, 30 parts of filler, 10 parts of composite nanofiber, 0.3 parts of fatty acid salt nucleating agent, 2 parts of antioxidant, 2 parts of pigment, and 0.5 parts of catalyst;

[0060] The preparation method of the low-cost high-toughness nylon specifically comprises the following steps:

[0061] 1) adding resin, water, monoamine, antioxidant and catalyst into a reaction kettle according to parts by weight and mixing uniformly, heating to 210° C., polymerizing under a pressure of 1.8 MPa for 7 hours, then slowly reducing the pressure to normal pressure, while raising the system temperature to 275° C., and continuing the reaction under a vacuum degree of 100 Pa for 7 hours to prepare a nylon substrate;

[0062] 2) The pretreated composite nanofibers are placed in a low-speed mixer together with a nylon substrate, a toughening agent, a filler, a fatty acid salt nucleating agent, and a pigment, and mixed for 10 minutes to obtain a blended material, which is then placed in a twin-screw extruder, mixed and melt-extruded at a temperature of 260° C. and a speed of 400 r / min. After cooling, pelletizing and screening are performed to obtain the desired high-toughness nylon;

[0063] The pretreatment process of the composite nanofiber is as follows:

[0064] 80 mg of molybdenum trioxide, 0.3 g of thioacetamide, and 2 g of urea were dissolved in a mixed solution of 50 mL of deionized water and 50 mL of anhydrous ethanol, and the mixture was thoroughly stirred to obtain a reaction solution. 5 g of the composite nanofibers were then added to the reaction solution, ultrasonically dispersed at 300 W for 30 min, and then transferred to a reactor and kept at 230° C. for 23 h. After the reaction, the mixture was repeatedly washed with deionized water and anhydrous ethanol, dried, and transferred to a tube furnace, kept at 630° C. for 5 h under an argon atmosphere, and naturally cooled with the furnace for later use.

[0065] At room temperature, add 3g of zinc nitrate hexahydrate to 150mL of anhydrous ethanol, stir to dissolve, then add 8g of 2-methylimidazole, stir thoroughly, add 10g of the above-mentioned spare product, ultrasonically disperse at 300W for 20min, transfer to a hydrothermal reactor, seal and react at 70°C for 3h, cool to room temperature after the reaction is completed, repeatedly wash with anhydrous toluene and dry.

[0066] The preparation method of the composite nanofiber is as follows:

[0067] 1) 3 g of silicon carbide nanofibers were added to 260 mL of toluene and ultrasonically dispersed at 300 W for 20 min. An inert gas was then introduced for 10 min and the mixture was stirred at 500 rpm. The mixture was then transferred to an oil bath and 0.8 g of 3-aminopropyltriethoxysilane was added. The mixture was reacted at 160° C. for 8 h. After the reaction was completed, the product was filtered, washed repeatedly, and dried to obtain pretreated nanofibers.

[0068] 2) Weigh 0.5 g of pretreated nanofibers, add 120 mL of deionized water, 38 mL of anhydrous ethanol and 0.8 mL of ammonia water, and after 300 W ultrasonic treatment for 50 min, add 1 g of resorcinol, stir thoroughly, add 1.6 mL of 40 wt% formaldehyde solution, and continue stirring at 200 r / min for 25 h. Then, the product is repeatedly washed with deionized water and anhydrous ethanol and dried, transferred to a tube furnace, kept warm at 650 ° C for 8 h under a nitrogen atmosphere, and immersed in a concentrated acid solution composed of concentrated nitric acid and concentrated sulfuric acid in a volume ratio of 1:3.5 after natural cooling. Stir at 300 r / min for 6 h, filter, wash repeatedly, and dry to obtain composite nanofibers.

[0069] Comparative Example 1: This comparative example is basically the same as Example 1, except that it does not contain composite nanofibers.

[0070] Comparative Example 2: This comparative example is basically the same as Example 1, except that silicon carbide nanofibers are used instead of composite nanofibers.

[0071] Comparative Example 3: This comparative example is basically the same as Example 1, except that pretreated nanofibers are used instead of composite nanofibers.

[0072] Comparative Example 4: This comparative example is basically the same as Example 1, except that the composite nanofibers are not pretreated.

[0073] Comparative Example 5: This comparative example is basically the same as Example 1, except that, in the pretreatment process of the composite nanofibers, no subsequent hydrothermal reaction is performed.

[0074] Test experiment:

[0075] The nylon samples provided in Examples 1-3 and Comparative Examples 1-5 were tested for performance using a universal mechanical properties testing machine. The results are shown in Table 1.

[0076] Table 1

[0077]

[0078]

[0079] As can be seen from Table 1, the nylon material of the present invention has excellent mechanical strength and high toughness, good stability, and greatly increased service life and application range.

[0080] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to the specific embodiments described. Obviously, many modifications and variations are possible based on the content of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A low-cost, high-toughness nylon, characterized in that: The nylon is made of the following raw materials in parts by weight: 80-120 parts of resin, 200-400 parts of water, 1-2 parts of monoamine, 0.3-0.8 parts of toughening agent, 20-30 parts of filler, 5-10 parts of composite nanofiber, 0.1-0.3 parts of fatty acid salt nucleating agent, 1-2 parts of antioxidant, 1-2 parts of pigment, and 0.1-0.5 parts of catalyst; The resin is composed of polydodecanediamine and polycaprolactam in a mass ratio of (10-12):1; The preparation method of the composite nanofiber is as follows: 1) adding silicon carbide nanofibers to toluene, ultrasonically dispersing for 10-20 minutes, then continuously introducing inert gas for 5-10 minutes with continuous stirring, then transferring to an oil bath, adding 3-aminopropyltriethoxysilane, and reacting at 150-160° C. for 6-8 hours. After the reaction is complete, the product is filtered, repeatedly washed, and then dried to obtain pretreated nanofibers; 2) Weighing an appropriate amount of pretreated nanofibers, adding deionized water, anhydrous ethanol and ammonia water, ultrasonically treating for 30-50 minutes, adding resorcinol, stirring thoroughly, adding formaldehyde solution and continuing stirring for 20-25 hours, then repeatedly washing the product with deionized water and anhydrous ethanol and drying it, transferring it to a tube furnace, keeping it at 600-650°C for 5-8 hours under a nitrogen atmosphere, cooling it naturally, immersing it in a concentrated acid solution, stirring it at 200-300 r / min for 3-6 hours, filtering it, repeatedly washing it, and drying it to obtain composite nanofibers; The method for preparing low-cost high-toughness nylon specifically comprises the following steps: 1) adding resin, water, monoamine, antioxidant and catalyst into a reaction kettle according to parts by weight and mixing evenly, heating to 190-210° C., polymerizing at a pressure of 1.2-1.8 MPa for 3-7 hours, then slowly reducing the pressure to normal pressure, while raising the system temperature to 260-275° C., and continuing the reaction at a vacuum degree of 30-100 Pa for 3-7 hours to prepare a nylon substrate; 2) The pretreated composite nanofibers are placed in a low-speed mixer together with a nylon substrate, a toughening agent, a filler, a fatty acid salt nucleating agent, and a pigment, and mixed for 5-10 minutes to obtain a blended material, which is then placed in a twin-screw extruder. After mixing, the mixture is melt-extruded, cooled, and pelletized and sieved to obtain the desired high-toughness nylon. The pretreatment process of the composite nanofiber is as follows: 1) dissolving molybdenum trioxide, thioacetamide, and urea in a mixed solution of deionized water and anhydrous ethanol, stirring thoroughly to obtain a reaction solution, then adding the composite nanofibers to the reaction solution, ultrasonically dispersing for 20-30 minutes, transferring the mixture to a reactor, and keeping the mixture at 200-230° C. for 18-23 hours. After the reaction is completed, the mixture is repeatedly washed with deionized water and anhydrous ethanol, dried, and transferred to a tube furnace, kept at 600-630° C. for 2-5 hours under an argon atmosphere, and cooled naturally in the furnace for later use; 2) At room temperature, zinc nitrate hexahydrate is added to anhydrous ethanol, stirred to dissolve, and then 2-methylimidazole is added. After thorough stirring, the above-mentioned standby product is added. After ultrasonic dispersion for 10-20 minutes, the mixture is transferred to a hydrothermal reactor, sealed, and reacted at 60-70°C for 1-3 hours. After the reaction is completed, the mixture is cooled to room temperature, repeatedly rinsed with anhydrous toluene, and then dried.

2. The low-cost, high-toughness nylon according to claim 1, characterized in that: The monoamine is any one of aliphatic monoamine, alicyclic monoamine, and aromatic monoamine; The toughening agent is maleic anhydride grafted polyolefin elastomer; The filler is composed of barium sulfate, titanium dioxide, and kaolin in a mass ratio of (2-3):1:(1-2); The antioxidant is composed of antioxidant 168 and antioxidant 1098 of equal mass; The catalyst is any one of sodium hypophosphite and phosphorous acid.

3. The low-cost, high-toughness nylon according to claim 1, characterized in that: In step 1), the ratio of the silicon carbide nanofibers, toluene, and 3-aminopropyltriethoxysilane is (1-3) g: (150-260) mL: (0.3-0.8) g; and the speed of the continuous stirring is 300-500 r / min.

4. The low-cost, high-toughness nylon according to claim 1, characterized in that: In step 2), the ratio of the amount of the pretreated nanofibers, deionized water, anhydrous ethanol, ammonia water, resorcinol, and formaldehyde solution is (0.1-0.5) g: (80-120) mL: (32-38) mL: (0.4-0.8) mL: (0.6-1.0) g: (1.0-1.6) mL; The concentration of the formaldehyde solution is 38-40wt%; The continuous stirring speed is 150-200 r / min; The concentrated acid solution is composed of concentrated nitric acid and concentrated sulfuric acid in a volume ratio of 1:(3.0-3.5).

5. The low-cost, high-toughness nylon according to claim 1, characterized in that: The twin-screw extruder has a temperature of 230-260° C. and a rotation speed of 300-400 r / min.

6. The low-cost, high-toughness nylon according to claim 1, characterized in that: In step 1), the usage ratio of molybdenum trioxide, thioacetamide, urea, deionized water, anhydrous ethanol, and composite nanofiber is (50-80) mg: (0.1-0.3) g: (1-2) g: (30-50) mL: (30-50) mL: (2-5) g.

7. The low-cost, high-toughness nylon according to claim 1, characterized in that: In step 2), the usage ratio of the zinc nitrate hexahydrate, anhydrous ethanol, 2-methylimidazole, and the standby product is (1-3) g: (100-150) mL: (3-8) g: (5-10) g.

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