A bio-based nylon material with excellent flame retardancy and its preparation method

Abstract

The present invention relates to the technical field of bio-based nylon materials, and particularly relates to a bio-based nylon material with excellent flame retardancy and a preparation method thereof. The bio-based nylon material comprises the following components in parts by weight: 40-60 parts of bio-based nylon 510, 15-20 parts of high flame-retardant cellulose fiber, 10-25 parts of polyphenylene ether, 5-8 parts of toughening agent, 1-5 parts of nucleating agent, 1-2 parts of antioxidant, and 1-2 parts of lubricant. In the bio-based nylon material of the present invention, by adding a special high flame-retardant cellulose fiber, a network structure with a high flame-retardant effect can be constructed and formed in the bio-based nylon material, which not only helps to improve the toughness of the bio-based nylon material, but also the formed multi-level network structure can effectively inhibit the combustion behavior of the material, so that the bio-based nylon material has a good flame-retardant effect, and a firm bond is formed between the formed network structure and the material matrix, and migration is not likely to occur, thereby enabling the flame-retardant effect of the material not to decrease and enabling a persistent high flame-retardant effect to be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of bio-based nylon materials, and specifically to a bio-based nylon material with excellent flame retardancy and a preparation method thereof. Background Art

[0002] Bio-based nylon refers to monomers for synthesizing polyamides manufactured by means of biology, chemistry, physics, etc. using renewable biomass as raw materials, and then high-molecular materials synthesized through polymerization reactions. It has characteristics such as being green, environmentally friendly, and having renewable raw materials. Bio-based materials have the characteristics of being green, environmentally friendly, having renewable raw materials, and being biodegradable, and have revolutionary significance under the development strategy of carbon neutrality. Extrusion molding, also known as extrusion molding, is an efficient, continuous, low-cost, and wide-applicable molding processing method, and is one of the commonly used production processes for plastic products in industry. Extrusion molding requires materials to have relatively high melt strength to ensure that the continuously molded materials have uniform wall thickness and bright appearance.

[0003] For example, the invention patent with the publication number CN111004501A discloses a modified bio-based nylon 56 material, a preparation method thereof, and applications. The modified bio-based nylon 56 material is prepared according to parts by weight from 55 - 70 parts of PA56, 0.3 - 1 part of antioxidant, 0.3 - 1 part of lubricant, 15 - 20 parts of flame retardant, and 15 - 25 parts of heat-conducting filler. The PA56 is obtained by polycondensation of pentamethylenediamine and adipic acid, with a relative viscosity between 2.4 - 3.2 and a molecular weight between 15,000 - 35,000. Using PA56 synthesized from pentamethylenediamine as the matrix resin, through the optimization of the formula system, the prepared modified bio-based nylon 56 material has high thermal conductivity, excellent flame retardancy, and good toughness, and is particularly suitable for high-temperature and high-pressure environments such as LED brackets, casings, sockets, and switches. By directly adding a flame retardant, although it can achieve a certain flame retardant effect, in a high-temperature environment, the flame retardant is prone to migration, resulting in uneven flame retardant effect of the material, with good flame retardant effect in some areas and poor flame retardant effect in some areas. Moreover, with the migration of the flame retardant, some flame retardants will migrate to the surface of the material and be lost, thereby reducing the flame retardant performance of the material and not having a persistent high flame retardant effect. Summary of the Invention

[0004] Aiming at the problems existing in the prior art, the purpose of the present invention is to provide a bio-based nylon material with excellent flame retardancy and a preparation method thereof.

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

[0006] A bio-based nylon material with excellent flame retardancy, the bio-based nylon material comprising the following components in parts by weight: 40-60 parts of bio-based nylon 510, 15-20 parts of high flame retardant cellulose fiber, 10-25 parts of polyphenylene ether, 5-8 parts of toughening agent, 1-5 parts of nucleating agent, 1-2 parts of antioxidant, and 1-2 parts of lubricant.

[0007] As a further preferred embodiment of the present invention, the toughening agent is at least one of styrene-butadiene-styrene block copolymer grafted maleic anhydride, hydrogenated styrene-butadiene-styrene block copolymer grafted maleic anhydride, styrene-butadiene-styrene block copolymer, and hydrogenated styrene-butadiene-styrene block copolymer;

[0008] The nucleating agent is at least one of long-chain saturated linear carboxylates, sorbitol compounds, xylitol compounds, and phosphorus compounds;

[0009] The antioxidant is at least one of copper salt antioxidants, hindered phenol antioxidants, hindered amine antioxidants, and phosphite antioxidants;

[0010] The lubricant is at least one of silicone lubricants and amide lubricants.

[0011] As a further preferred embodiment of the present invention, the preparation method of the high flame retardant cellulose fiber is as follows:

[0012] 1) Add boric acid, calcium oxide, and sodium chloride to deionized water in sequence, pour it into a ball milling tank, ball mill in a ball mill for 5-8 h to obtain a lime milk slurry, then add boric acid and deionized water to the lime milk slurry, heat to 95-100 °C and stir for 4-6 h, while carrying out condensation reflux, let it stand for 12-18 h and then carry out suction filtration, repeatedly wash and filter the filter cake with deionized water at 80-85 °C, then add an appropriate amount of deionized water and put it into a ball mill to ball mill for 7-10 h, filter and dry to obtain calcium borate;

[0013] 2) Add magnesium hydroxide to a high-speed crusher, dropwise add silane coupling agent KH550 and deionized water, stir at 2000-3000 r / min during the dropping process, take out the powder after mixing evenly, place it in a blast drying oven, dry at 80-86 °C for 4-6 h, put the dried product into the high-speed crusher again, mix at 2000-3000 r / min for 1-3 min to obtain modified magnesium hydroxide;

[0014] 3) Put calcium borate and modified magnesium hydroxide into a high-speed crusher, mix at high speed for 1-3 min to obtain a composite flame retardant, use acetic acid solution with a concentration of 50-56 wt% as a solvent to prepare a spinning solution of chitosan and polyvinyl alcohol, then add the composite flame retardant to the spinning solution, disperse evenly by ultrasonic to form an electrospinning solution;

[0015] 4) Electrospin the electrospinning solution, using the modified cellulose fiber as the receiving material, then spray phytic acid solution on the surface of the product, and control the spraying amount ratio of the phytic acid solution to the product to be (4 - 6) mL: 100 g, and then dry it at 60 - 70 °C for 12 - 15 h.

[0016] As a further preferred embodiment of the present invention, the dosage ratio of boric acid, calcium oxide, sodium chloride, and deionized water is (80 - 100) g: (24 - 28) g: (14 - 17) g: (240 - 320) mL;

[0017] The dosage ratio of the lime milk slurry, boric acid, and deionized water is (380 - 460) g: (190 - 210) g: (240 - 300) mL;

[0018] The dosage ratio of magnesium hydroxide, silane coupling agent KH550, and deionized water is (100 - 130) g: (6 - 10) g: (10 - 20) mL.

[0019] As a further preferred embodiment of the present invention, the mass ratio of calcium borate to modified magnesium hydroxide is 1: (1 - 3);

[0020] The mass ratio of chitosan to polyvinyl alcohol is (80 - 95): (5 - 20);

[0021] The total concentration of the spinning solution is 3 - 5 wt%;

[0022] The addition amount of the composite flame retardant is 1 - 3% of the mass of the spinning solution.

[0023] As a further preferred embodiment of the present invention, in the electrospinning, the static voltage is 15 - 18 kV, the feeding speed is 0.3 - 0.6 mL / h, the receiving distance is 12 - 15 cm, and the rotation speed of the receiving roller is 150 - 200 rpm;

[0024] The concentration of the phytic acid solution is 1 - 3 wt%.

[0025] As a further preferred embodiment of the present invention, the preparation method of the modified cellulose fiber is as follows:

[0026] 1) Tear the wood pulp board into small pieces, soak it in clean water for 2 - 5 h, then use a disintegrator to disperse it at high speed until there is no blocky pulp board, then use a 400 - 600 - mesh pulp bag to squeeze out the water from the dispersed fibers, then put them into a sealed bag, and after the water balance, place the fibers in a blast drying oven and dry them at 105 - 115 °C for 6 - 10 h to obtain cellulose fibers;

[0027] 2) Weigh an appropriate amount of cellulose fibers. First, dissolve diammonium hydrogen phosphate and urea in deionized water, then add the cellulose fibers, and stir for 1 - 3 h. After mixing evenly, spread it on a PET film, put it into a forced-air drying oven, and dry it at 70 - 80 °C for 12 - 16 h to obtain pretreated cellulose fibers;

[0028] 3) Add the pretreated cellulose fibers to an oil bath pan and stir for 40 - 60 min. After the stirring ends, pour the fibers into a pulp bag with 400 - 600 mesh, wash them, and then dry them to obtain modified cellulose fibers.

[0029] As a further preferred embodiment of the present invention, the mass ratio of the cellulose fibers, diammonium hydrogen phosphate, and urea is 1:(1.5 - 3.0):(10 - 18);

[0030] The dosage ratio of the cellulose fibers to deionized water is (15 - 30) g:(150 - 300) mL.

[0031] As a further preferred embodiment of the present invention, the temperature of the oil bath pan is 160 - 170 °C;

[0032] The operation of the washing is as follows: First, wash repeatedly with boiling deionized water, and then wash repeatedly with deionized water at room temperature.

[0033] A preparation method of a bio-based nylon material with excellent flame retardancy specifically includes the following steps:

[0034] 1) According to the weight parts, mix bio-based nylon 510, high flame-retardant cellulose fibers, polyphenylene ether, toughening agent, nucleating agent, antioxidant, and lubricant evenly to obtain a premix;

[0035] 2) Place the premix in a twin-screw extruder, carry out melt mixing and extrusion granulation to obtain the required bio-based nylon material.

[0036] Compared with the prior art, the beneficial effects of the present invention are:

[0037] In the present invention, phosphate and urea are used to chemically modify cellulose fibers to obtain phosphorylated modified cellulose fibers. Through the phosphorylated modification treatment, phosphate groups are grafted onto the cellulose fibers. When burning, the phosphate groups will dehydrate and carbonize the cellulose, and then form a carbon layer on the surface to isolate air and heat, thereby playing a certain flame retardant effect. Moreover, the presence of urea can prevent the cellulose from degrading due to the phosphoric acid generated during the high-temperature curing process, and can protect the phosphoric acid, making the formed modified cellulose fibers have stable flame retardancy.

[0038] In the present invention, calcium borate flakes are prepared from calcium oxide and boric acid by the lime milk method. When calcium borate decomposes at high temperature, it will release crystal water to lower the surface temperature of the material, and the boron oxide generated by decomposition will cover the surface of the material, thus further hindering the heat transfer and inhibiting the combustion behavior of the material; the magnesium hydroxide is modified with silane coupling agent KH550, which helps to enhance the synergistic effect between calcium borate and magnesium hydroxide, so that when the two are used in combination, they have a better flame retardant effect, can inhibit the combustion behavior of the material, and thus enable the material to have a better flame retardant effect; the composite flame retardant formed by compounding calcium borate and modified magnesium hydroxide is combined with chitosan, phytic acid, and polyvinyl alcohol to form an electrospinning solution, and by electrospinning, it is sprayed on the surface of the modified cellulose fiber, so as to form a flame retardant layer on the surface of the modified cellulose fiber. The phytic acid in the flame retardant layer will generate phosphoric acid during pyrolysis, which can catalyze chitosan to form carbon, and the generated phosphorus-containing free radicals can eliminate the free radicals in the flame zone, thus hindering the combustion reaction. Moreover, chitosan releases non-combustible gases such as ammonia and nitrogen at high temperature, on the one hand, making the carbon layer expand and thicken, and on the other hand, it can also dilute the concentration of combustible gases, so that the formed highly flame-retardant cellulose fiber has excellent flame retardant properties; by adding it to the bio-based nylon material, a network structure with a high flame retardant effect can be constructed in the bio-based nylon material, which not only helps to improve the toughness of the bio-based nylon material, but also the formed multi-level network structure can effectively inhibit the combustion behavior of the material, making the bio-based nylon material have a good flame retardant effect, and the formed network structure forms a firm bond with the material matrix and is not easy to migrate, so that the flame retardant effect of the material will not decrease and can have a persistent high flame retardant effect.

[0039] In the bio-based nylon material of the present invention, by adding a special highly flame-retardant cellulose fiber, a network structure with a high flame retardant effect can be constructed in the bio-based nylon material, which not only helps to improve the toughness of the bio-based nylon material, but also the formed multi-level network structure can effectively inhibit the combustion behavior of the material, making the bio-based nylon material have a good flame retardant effect, and the formed network structure forms a firm bond with the material matrix and is not easy to migrate, so that the flame retardant effect of the material will not decrease and can have a persistent high flame retardant effect. Detailed implementation manners

[0040] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0041] In the embodiments of the present invention, the bio-based nylon 510 is provided by Dongguan Yanmei New Materials Technology Co., Ltd.; the toughening agent is styrene-butadiene-styrene block copolymer grafted maleic anhydride; the nucleating agent is Clariant nucleating agent NaV101; the antioxidant is antioxidant 1010; the lubricant is oleic acid amide.

[0042] Example 1

[0043] A bio-based nylon material with excellent flame retardant performance, the bio-based nylon material comprises the following components in parts by weight: 40 parts of bio-based nylon 510, 15 parts of high flame retardant cellulose fiber, 10 parts of polyphenylene ether, 5 parts of toughening agent, 1 part of nucleating agent, 1 part of antioxidant, 1 part of lubricant;

[0044] The preparation method of the bio-based nylon material specifically comprises the following steps:

[0045] 1) According to the parts by weight, mix bio-based nylon 510, high flame retardant cellulose fiber, polyphenylene ether, toughening agent, nucleating agent, antioxidant, and lubricant evenly to obtain a premix.

[0046] 2) Place the premix in a twin-screw extruder for melt mixing and extrusion granulation to obtain the required bio-based nylon material.

[0047] Among them, the preparation method of the high flame retardant cellulose fiber is as follows:

[0048] 1) Tear the wood pulp board into small pieces, soak it in clear water for 2 h, then use a defibrator to disperse it at high speed until there are no blocky pulp boards, then use a 400-mesh pulp bag to squeeze out the water from the dispersed fibers, then put them into a sealed bag, and after the water balance, place the fibers in a forced-air oven and dry them at 105 °C for 6 h to obtain cellulose fibers.

[0049] 2) Weigh 15 g of cellulose fibers, and then according to the mass ratio of cellulose fiber, diammonium hydrogen phosphate, and urea of 1:1.5:10, first dissolve diammonium hydrogen phosphate and urea in 150 mL of deionized water, then add cellulose fibers, stir at 200 r / min for 1 h, spread them evenly on a PET film after mixing, and put them into a forced-air drying oven to dry at 70 °C for 12 h to obtain pretreated cellulose fibers.

[0050] 3) Add the pretreated cellulose fibers to an oil bath pot, stir at 160 °C at 100 r / min for 40 min, after the stirring is completed, pour the fibers into a 400-mesh pulp bag, wash them repeatedly with boiling deionized water, and then wash them repeatedly with deionized water at room temperature, and dry them to obtain modified cellulose fibers.

[0051] 4) Add 80 g of boric acid, 24 g of calcium oxide, and 14 g of sodium chloride to 240 mL of deionized water in sequence, pour it into a ball milling tank, and ball mill for 5 h in a ball mill to obtain a lime milk slurry. Then add 190 g of boric acid and 240 mL of deionized water to 380 g of the lime milk slurry, heat to 95 °C, stir at 300 r / min for 4 h, while carrying out condensation reflux. After standing for 12 h, carry out suction filtration, repeatedly wash the filter cake with 80 °C deionized water and carry out suction filtration, then add an appropriate amount of deionized water and put it into a ball mill to ball mill for 7 h, carry out suction filtration and then dry to obtain calcium borate;

[0052] 5) Add 100 g of magnesium hydroxide to a high-speed grinder, dropwise add 6 g of silane coupling agent KH550 and 10 mL of deionized water, and stir at 2000 r / min during the dropping process. After mixing evenly, take out the powder, place it in a blast drying oven, and dry at 80 °C for 4 h. Put the dried product into the high-speed grinder again and mix at 2000 r / min for 1 min to obtain modified magnesium hydroxide;

[0053] 6) Put calcium borate and modified magnesium hydroxide into a high-speed grinder according to a mass ratio of 1:1, and mix at high speed for 1 min to obtain a composite flame retardant. Use a 50 wt% acetic acid solution as a solvent to prepare a spinning solution with a mass ratio of chitosan to polyvinyl alcohol of 80:20, and the total concentration of the spinning solution is 3 wt%. Then add the composite flame retardant to the spinning solution, and control the addition amount of the composite flame retardant to be 1% of the mass of the spinning solution. After ultrasonic dispersion and uniformity, an electrospinning solution is formed;

[0054] 7) Carry out electrospinning on the electrospinning solution, with a static voltage of 15 kV, a feeding speed of 0.3 mL / h, a receiving distance of 12 cm, use modified cellulose fiber as the receiving material and keep the rotation speed of the receiving roller at 150 rpm. Then spray a 1 wt% phytic acid solution on the surface of the product, and control the spraying amount ratio of the phytic acid solution to the product to be 4 mL:100 g, and then dry at 60 °C for 12 h.

[0055] Example 2

[0056] A bio-based nylon material with excellent flame retardancy, which contains the following components in parts by weight: 50 parts of bio-based nylon 510, 18 parts of high flame retardant cellulose fiber, 20 parts of polyphenylene ether, 7 parts of toughening agent, 3 parts of nucleating agent, 2 parts of antioxidant, 2 parts of lubricant;

[0057] The preparation method of the bio-based nylon material specifically includes the following steps:

[0058] 1) According to the parts by weight, mix bio-based nylon 510, high flame retardant cellulose fiber, polyphenylene ether, toughening agent, nucleating agent, antioxidant, and lubricant evenly to obtain a premix;

[0059] 2) Place the premix in a twin-screw extruder for melt mixing and extrusion granulation to obtain the required bio-based nylon material.

[0060] Among them, the preparation method of the high flame-retardant cellulose fiber is as follows:

[0061] 1) Tear the wood pulp board into small pieces, soak them in clean water for 3 h, then use a defibrator to disperse them at high speed until there are no blocky pulp boards. Then use a 500-mesh pulp bag to squeeze out the water from the dispersed fibers, and then put them into a sealed bag. After the water balance, place the fibers in a blast drying oven and dry them at 110 °C for 8 h to obtain cellulose fibers;

[0062] 2) Weigh 25 g of cellulose fibers, and then according to the mass ratio of cellulose fibers, diammonium hydrogen phosphate, and urea of 1:2.5:15, first dissolve diammonium hydrogen phosphate and urea in 250 mL of deionized water, then add cellulose fibers, stir at 250 r / min for 2 h, spread them evenly on a PET film after mixing, and put them into a blast drying oven to dry at 75 °C for 15 h to obtain pretreated cellulose fibers;

[0063] 3) Add the pretreated cellulose fibers to an oil bath pot, stir at 165 °C and 130 r / min for 50 min. After the stirring is completed, pour the fibers into a 500-mesh pulp bag, wash them repeatedly with boiling deionized water, and then wash them repeatedly with deionized water at room temperature. After drying, obtain modified cellulose fibers;

[0064] 4) Add 90 g of boric acid, 26 g of calcium oxide, and 15 g of sodium chloride to 300 mL of deionized water in sequence, pour them into a ball milling tank, and ball mill in a ball mill for 7 h to obtain a lime milk slurry. Then add 200 g of boric acid and 260 mL of deionized water to 420 g of the lime milk slurry, heat it to 98 °C, stir at 400 r / min for 5 h, while performing condensation reflux. After standing for 15 h, perform suction filtration, wash the filter cake repeatedly with 82 °C deionized water and perform suction filtration, then add an appropriate amount of deionized water and put it into a ball mill to ball mill for 8 h, perform suction filtration and then dry to obtain calcium borate;

[0065] 5) Add 120 g of magnesium hydroxide to a high-speed crusher, dropwise add 8 g of silane coupling agent KH550 and 15 mL of deionized water, stir at 2500 r / min during the dropping process, take out the powder after mixing evenly, place it in a blast drying oven, dry it at 83 °C for 5 h, put the dried product into the high-speed crusher again, and mix at 2500 r / min for 2 min to obtain modified magnesium hydroxide;

[0066] 6) Put calcium borate and modified magnesium hydroxide into a high-speed grinder according to a mass ratio of 1:2, and mix them at high speed for 2 min to obtain a composite flame retardant. Use acetic acid solution with a concentration of 53 wt% as the solvent to prepare a spinning solution with a mass ratio of chitosan to polyvinyl alcohol of 90:10, and the total concentration of the spinning solution is 4 wt%. Then add the composite flame retardant to the spinning solution, and control the addition amount of the composite flame retardant to be 2% of the mass of the spinning solution. After ultrasonic dispersion, an electrospinning solution is formed;

[0067] 7) Perform electrospinning on the electrospinning solution with a static voltage of 17 kV, a feeding speed of 0.5 mL / h, and a receiving distance of 13 cm. Use modified cellulose fiber as the receiving material and keep the rotation speed of the receiving roller at 180 rpm. Then spray 2 wt% phytic acid solution on the surface of the product, and control the spraying amount ratio of the phytic acid solution to the product to be 5 mL:100 g. Then dry it at 65 °C for 13 h.

[0068] Example 3

[0069] A bio-based nylon material with excellent flame retardancy, which contains the following components in parts by weight: 60 parts of bio-based nylon 510, 20 parts of high flame retardant cellulose fiber, 25 parts of polyphenylene ether, 8 parts of toughening agent, 5 parts of nucleating agent, 2 parts of antioxidant, and 2 parts of lubricant;

[0070] The preparation method of the bio-based nylon material specifically includes the following steps:

[0071] 1) According to the parts by weight, mix bio-based nylon 510, high flame retardant cellulose fiber, polyphenylene ether, toughening agent, nucleating agent, antioxidant, and lubricant evenly to obtain a premix;

[0072] 2) Place the premix in a twin-screw extruder for melt mixing and extrusion granulation to obtain the required bio-based nylon material.

[0073] Among them, the preparation method of the high flame retardant cellulose fiber is as follows:

[0074] 1) Tear the wood pulp board into small pieces, soak it in clean water for 5 h, then use a beating machine to disperse it at high speed until there is no blocky pulp board, and then use a 600-mesh pulp bag to squeeze out the water from the dispersed fibers. Then put them into a sealed bag. After the water balance, place the fibers in a blast drying oven and dry them at 115 °C for 10 h to obtain cellulose fibers;

[0075] 2) Weigh 30 g of cellulose fibers. Then, according to the mass ratio of cellulose fibers, diammonium hydrogen phosphate, and urea being 1:3:18, first dissolve diammonium hydrogen phosphate and urea in 300 mL of deionized water, then add the cellulose fibers, stir at 300 r / min for 3 h, spread evenly on a PET film after mixing, place it in a forced-air drying oven, and dry at 80 °C for 16 h to obtain pretreated cellulose fibers;

[0076] 3) Add the pretreated cellulose fibers to an oil bath pan, stir at 160 r / min at 170 °C for 60 min. After stirring, pour the fibers into a 600-mesh pulp bag, wash repeatedly with boiling deionized water, and then wash repeatedly with deionized water at room temperature. After drying, obtain modified cellulose fibers;

[0077] 4) Add 100 g of boric acid, 28 g of calcium oxide, and 17 g of sodium chloride to 320 mL of deionized water in sequence, pour it into a ball milling tank, and ball mill in a ball mill for 8 h to obtain a lime milk slurry. Then add 210 g of boric acid and 300 mL of deionized water to 460 g of the lime milk slurry, heat to 100 °C, stir at 500 r / min for 6 h, while carrying out condensation reflux. After standing for 18 h, carry out suction filtration, wash the filter cake repeatedly with 85 °C deionized water and carry out suction filtration, then add an appropriate amount of deionized water and put it into a ball mill to ball mill for 10 h. After suction filtration and drying, obtain calcium borate;

[0078] 5) Add 130 g of magnesium hydroxide to a high-speed grinder, dropwise add 10 g of silane coupling agent KH550 and 20 mL of deionized water, and stir at 3000 r / min during the dropping process. After mixing evenly, take out the powder, place it in a forced-air drying oven, and dry at 86 °C for 6 h. Put the dried product into the high-speed grinder again and mix at 3000 r / min for 3 min to obtain modified magnesium hydroxide;

[0079] 6) Put calcium borate and modified magnesium hydroxide into a high-speed grinder according to a mass ratio of 1:3, and mix at high speed for 3 min to obtain a composite flame retardant. Use a 56 wt% acetic acid solution as a solvent to prepare a spinning solution with a mass ratio of chitosan to polyvinyl alcohol of 95:5, and the total concentration of the spinning solution is 5 wt%. Then add the composite flame retardant to the spinning solution, and control the addition amount of the composite flame retardant to be 3% of the mass of the spinning solution. After ultrasonic dispersion and uniformity, form an electrospinning solution;

[0080] 7) Carry out electrospinning on the electrospinning solution, with an electrostatic voltage of 18 kV, a propulsion speed of 0.6 mL / h, a receiving distance of 15 cm, use modified cellulose fibers as the receiving material and keep the rotation speed of the receiving roller at 200 rpm. Then spray a 3 wt% phytic acid solution on the surface of the product, and control the spraying amount ratio of the phytic acid solution to the product to be 6 mL:100 g. Then dry at 70 °C for 15 h.

[0081] Comparative Example 1: This comparative example is basically the same as Example 1, except that an organic hypophosphite flame retardant is used to replace the highly flame-retardant cellulose fiber.

[0082] Comparative Example 2: This comparative example is basically the same as Example 1, except that in the preparation of the highly flame-retardant cellulose fiber, cellulose fiber is used to replace the modified cellulose fiber.

[0083] Comparative Example 3: This comparative example is basically the same as Example 1, except that in the preparation of the highly flame-retardant cellulose fiber, pretreated cellulose fiber is used to replace the modified cellulose fiber.

[0084] Comparative Example 4: This comparative example is basically the same as Example 1, except that in the preparation of the highly flame-retardant cellulose fiber, step 4) is omitted.

[0085] Comparative Example 5: This comparative example is basically the same as Example 1, except that in the preparation of the highly flame-retardant cellulose fiber, step 5) is omitted.

[0086] Testing experiment:

[0087] The samples of the bio-based nylon materials provided in Examples 1-3 and Comparative Examples 1-5 were first placed in an environment of 120 °C for 48 h, and after cooling to room temperature, the flame retardancy was measured according to UL-94. The results are shown in Table 1.

[0088] Table 1

[0089] Example 1 Example 2 Example 3 Comparative Example 1 Flame retardancy rating (1.6 mm) V0 V0 V0 V2 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Flame retardancy rating (1.6 mm) V1 V1 V1 V1

[0090] It can be seen from Table 1 that the bio-based nylon material in the present invention has a stable flame retardant effect, and a long-term high-temperature environment will not cause a decrease in the flame retardancy, and has a persistent high flame retardant effect.

[0091] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor limit the invention to the specific embodiments described. Obviously, many modifications and variations can be made according to the content of this specification. These embodiments are selected and specifically described in this specification to better explain the principle and practical application of the present invention, so that those skilled in the art can well understand and utilize the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A bio-based nylon material with excellent flame retardancy performance, characterized in that, the bio-based nylon material comprises the following components in parts by weight: 40-60 parts of bio-based nylon 510, 15-20 parts of high flame retardant cellulose fiber, 10-25 parts of polyphenylene ether, 5-8 parts of toughening agent, 1-5 parts of nucleating agent, 1-2 parts of antioxidant, 1-2 parts of lubricant; The preparation method of the high flame retardant cellulose fiber is as follows: 1) Add boric acid, calcium oxide and sodium chloride to deionized water in sequence, pour it into a ball milling tank, ball mill in a ball mill for 5-8 h to obtain a lime milk slurry, then add boric acid and deionized water to the lime milk slurry, heat to 95-100 °C and stir for 4-6 h, while carrying out condensation reflux, let it stand for 12-18 h and then carry out suction filtration, repeatedly wash and suction filter the filter cake with deionized water at 80-85 °C, then add an appropriate amount of deionized water and put it into a ball mill to ball mill for 7-10 h, suction filter and dry to obtain calcium borate; 2) Add magnesium hydroxide to a high-speed pulverizer, dropwise add silane coupling agent KH550 and deionized water, stir at 2000-3000 r / min during the dropping process, take out the powder after mixing evenly, place it in a blast drying oven, dry at 80-86 °C for 4-6 h, put the dried product into the high-speed pulverizer again, mix at 2000-3000 r / min for 1-3 min to obtain modified magnesium hydroxide; 3) Put calcium borate and modified magnesium hydroxide into a high-speed pulverizer, mix at high speed for 1-3 min to obtain a composite flame retardant, use acetic acid solution with a concentration of 50-56 wt% as a solvent to prepare a spinning solution of chitosan and polyvinyl alcohol, then add the composite flame retardant to the spinning solution, ultrasonically disperse evenly to form an electrospinning solution; 4) Carry out electrospinning on the electrospinning solution, use modified cellulose fiber as the receiving material, then spray phytic acid solution on the surface of the product, and control the spraying amount ratio of the phytic acid solution to the product to be (4-6) mL: 100 g, and then dry at 60-70 °C for 12-15 h; The dosage ratio of boric acid, calcium oxide, sodium chloride and deionized water is (80-100) g: (24-28) g: (14-17) g: (240-320) mL; The dosage ratio of the lime milk slurry, boric acid and deionized water is (380-460) g: (190-210) g: (240-300) mL; The dosage ratio of magnesium hydroxide, silane coupling agent KH550 and deionized water is (100-130) g: (6-10) g: (10-20) mL; The mass ratio of calcium borate and modified magnesium hydroxide is 1: (1-3); The mass ratio of chitosan and polyvinyl alcohol is (80-95): (5-20); The total concentration of the spinning solution is 3-5 wt%; The addition amount of the composite flame retardant is 1-3% of the mass of the spinning solution; In the electrospinning, the static voltage is 15-18 kV, the propulsion speed is 0.3-0.6 mL / h, the receiving distance is 12-15 cm, and the rotation speed of the receiving roller is 150-200 rpm; The concentration of the phytic acid solution is 1-3 wt%. The preparation method of the modified cellulose fiber is as follows: 1) Tear the wood pulp sheet into small pieces, soak them in clear water for 2-5 h, then use a disintegrator to disperse them at high speed until there are no lumps of pulp sheet. Then use a 400-600 mesh pulp bag to squeeze out the water from the dispersed fibers, and then put them into a sealed bag. After the water balance, place the fibers in a forced-air oven and dry them at 105-115 °C for 6-10 h to obtain cellulose fibers; 2) Weigh an appropriate amount of cellulose fibers. First, dissolve diammonium hydrogen phosphate and urea in deionized water, then add the cellulose fibers and stir for 1-3 h. After mixing evenly, spread them on a PET film and put them into a forced-air drying oven to dry at 70-80 °C for 12-16 h to obtain pretreated cellulose fibers; 3) Add the pretreated cellulose fibers to an oil bath pan and stir for 40-60 min. After the stirring ends, pour the fibers into a 400-600 mesh pulp bag, wash them and then dry them to obtain modified cellulose fibers; The mass ratio of the cellulose fiber, diammonium hydrogen phosphate, and urea is 1:(1.5-3.0):(10-18); The dosage ratio of the cellulose fiber to deionized water is (15-30) g:(150-300) mL; The temperature of the oil bath pan is 160-170 °C; The operation of the washing is as follows: First, wash repeatedly with boiling deionized water, and then wash repeatedly with deionized water at room temperature.

2. According to a bio-based nylon material with excellent flame retardancy according to claim 1, characterized in that the toughening agent is at least one of styrene-butadiene-styrene block copolymer grafted maleic anhydride, hydrogenated styrene-butadiene-styrene block copolymer grafted maleic anhydride, styrene-butadiene-styrene block copolymer, and hydrogenated styrene-butadiene-styrene block copolymer; the nucleating agent is at least one of long-chain saturated linear carboxylates, sorbitol compounds, xylitol compounds, and phosphorus compounds; the antioxidant is at least one of copper salt antioxidants, hindered phenol antioxidants, hindered amine antioxidants, and phosphite antioxidants; the lubricant is at least one of silicone lubricants and amide lubricants.

3. According to the preparation method of a bio-based nylon material with excellent flame retardancy according to any one of claims 1-2, characterized in that it specifically includes the following steps: 1) According to the weight parts, mix bio-based nylon 510, high flame-retardant cellulose fibers, polyphenylene ether, toughening agent, nucleating agent, antioxidant, and lubricant evenly to obtain a premix; 2) Place the premix in a twin-screw extruder for melt mixing and extrusion granulation to obtain the required bio-based nylon material.