High-rigidity and high-resilience nylon composite material for human waist support chair in sitting position and preparation method and application thereof

Abstract

The present application relates to the technical field of nylon composite material, in particular to a high-rigidity and high-resilience nylon composite material for waist support chair for human body, and a preparation method and application thereof, which comprises the following raw materials: polyketone / nylon nanocomposite material, zinc oxide, modified glass fiber, glass microspheres, ethylene bis-stearamide, N,N'-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide], titanium dioxide. Through the copolymerization grafting structure of polyketone and nylon, the material has high rigidity of polyketone and toughness of nylon; the introduction of styrene-ethylene / butylene-styrene block copolymer grafted maleic anhydride effectively improves the phase separation problem of polyketone and nylon, and the addition of cellulose nanocrystals further enhances the interfacial bonding force; the unique nanocomposite structure can effectively disperse stress, ensuring that the material still maintains good resilience after repeated stress.

Description

Technical Field

[0001] This invention relates to the field of nylon composite materials technology, specifically to a high-rigidity, high-resilience nylon composite material for a lumbar support chair, its preparation method, and its application. Background Technology

[0002] With the fast pace of life and changes in lifestyle, prolonged sitting has become the norm for modern people. Sitting for long periods can easily lead to lumbar problems such as lumbar muscle strain and scoliosis. As a functional chair that improves posture and relieves back pain and fatigue caused by prolonged sitting, the lumbar support chair has received widespread attention in recent years. Currently, most lumbar support chairs on the market are made of modified polypropylene (PP) material. For people of average weight, lumbar support chairs made of PP material can have a certain degree of health benefits.

[0003] However, for heavier individuals, the stiffness and resilience provided by PP material lumbar support chairs are significantly insufficient, failing to effectively support the body weight and offering limited protection for the lumbar spine. In some cases, the chair may even collapse, failing to meet users' performance requirements for lumbar support chairs and potentially causing further damage to the user's lumbar health. Therefore, we propose a high-stiffness, high-resilience nylon composite material for lumbar support chairs, along with its preparation method and applications. Summary of the Invention

[0004] The purpose of this invention is to provide a high-rigidity, high-resilience nylon composite material for lumbar support chairs, its preparation method, and its application, in order to solve the problem mentioned in the background art that for heavier people, PP material lumbar support chairs provide insufficient rigidity and resilience, cannot effectively support the weight of the body, have limited protection for the lumbar spine, and may even collapse when seated. This not only fails to meet the performance requirements of users for lumbar support chairs, but also causes further damage to the user's lumbar spine health.

[0005] In a first aspect, the present invention provides a high-rigidity, high-resilience nylon composite material for a lumbar support chair, comprising the following raw materials: polyketone / nylon 6 nanocomposite material, zinc oxide, modified glass fiber, glass microspheres, ethylene bis-stearamide, N,N'-hexane-1,6-dimethylbis[3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide], and titanium dioxide;

[0006] Modified glass fiber is prepared by hydrolysis and condensation reaction of bis-[3-(triethoxysilyl)propyl]tetrasulfide with glass fiber, followed by deposition of nano-zinc oxide on its surface;

[0007] The polyketone / nylon 6 nanocomposite material is prepared by reacting polyketone with nylon 6 to generate a polyketone-grafted nylon 6 copolymer, and then grafting maleic anhydride and cellulose nanocrystals onto a styrene-ethylene / butene-styrene block copolymer.

[0008] Preferably, the polyketone / nylon 6 nanocomposite material comprises 60-70 parts by weight, zinc oxide 0.5-1 parts by weight, modified glass fiber 15-20 parts by weight, glass microspheres 5-8 parts by weight, ethylene bis-stearamide 0.3-0.5 parts by weight, N,N'-hexane-1,6-dimethylbis[3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide] 0.2-0.3 parts by weight, and titanium dioxide 1-2 parts by weight.

[0009] Modified glass fiber serves as the main load-bearing skeleton, forming chemical bonds with the matrix through surface nano-zinc oxide anchor points, thus directionally transmitting stress. In addition, the stress dispersion of zinc oxide nanoparticles allows the fiber to undergo minute displacements under stress, releasing local stress concentrations. The hollow structure of the microspheres undergoes elastic collapse under compression, while the bending deformation of the fibers absorbs impact energy, forming a spring-like step-by-step buffer to maintain the overall stability of the structure.

[0010] Preferably, the modified glass fiber is prepared by the following method:

[0011] Bis-[3-(triethoxysilyl)propyl]tetrasulfide was mixed with ethanol / water at a volume ratio of 9:1, the pH was adjusted to 4-5 with aqueous acetic acid, and the mixture was stirred at 300-400 rpm for 30-45 min to obtain a hydrolysate of bis-[3-(triethoxysilyl)propyl]tetrasulfide.

[0012] Pretreated glass fibers were immersed in a bis-[3-(triethoxysilyl)propyl]tetrasulfide hydrolysate at a solid-liquid ratio of 1:20 and reacted in a water bath at 50-60℃ for 3-4 hours. After the reaction was completed, the fibers were rinsed with ethanol 2-3 times and cured at 70-80℃ for 0.5-1 hours to obtain bis-[3-(triethoxysilyl)propyl]tetrasulfide modified glass fibers.

[0013] Glass fibers modified with bis-[3-(triethoxysilyl)propyl]tetrasulfide were immersed in zinc oxide sol and reacted at 100-110℃ for 4-6 h. After the reaction was completed, the fibers were washed 2-3 times with deionized water, dried at 100-120℃ for 1-2 h, and annealed at 150-200℃ for 1-1.5 h to obtain the modified glass fibers.

[0014] The ethoxy group of the silane coupling agent hydrolyzes to generate silanol, which undergoes a condensation reaction with the hydroxyl groups on the glass fiber surface to form Si-O-Si covalent bonds, thereby grafting long organic chains (containing sulfur bonds) onto the glass fiber surface. This chemical bonding enhances the adhesion between the glass fiber and the resin matrix, significantly improving the mechanical properties of the composite material, such as impact resistance and peel resistance. Nano-zinc oxide forms a uniform coating on the glass fiber surface, significantly improving the resilience of the composite material through physical cross-linking and nano-reinforcement effects.

[0015] Preferably, the concentration of the acetic acid aqueous solution is 0.5-1%.

[0016] Preferably, the preparation steps of the zinc oxide sol are as follows: zinc acetate with a concentration of 0.05-0.1 mol / L and hexamethylenetetramine with a concentration of 0.05-0.1 mol / L are dissolved in deionized water at a molar ratio of 1:1, polyvinylpyrrolidone with a concentration of 0.01-0.05 mol / L is added, and the mixture is stirred at a speed of 200-300 rpm for 15-30 min to obtain zinc oxide sol.

[0017] Preferably, the preparation method of the polyketone / nylon 6 nanocomposite material is as follows:

[0018] Styrene-ethylene / butene-styrene block copolymer grafted with maleic anhydride (8-10% by mass of polyketone / nylon 6 nanocomposite material) was dissolved in toluene, and cellulose nanocrystal dispersion was added. The mixture was stirred at 300-400 rpm for 1-2 hours at 50-60℃. After the reaction was completed, toluene was removed by rotary evaporation at 50-60℃ to obtain composite particles of cellulose nanocrystals coated with styrene-ethylene / butene-styrene block copolymer grafted with maleic anhydride.

[0019] Polyketone / nylon 6 was premixed at a weight ratio of 6:4 and fed into a twin-screw extruder. Composite particles of styrene-ethylene / butene-styrene block copolymer grafted with maleic anhydride and coated with cellulose nanocrystals and dicumyl peroxide were added. The temperature was set at 200-235℃, the speed at 200-300 rpm, and the pressure at -0.05~-0.08 MPa. The melt was granulated by a pelletizer, dried at 60-80℃ for 3-4 hours, and annealed at 100-110℃ for 1-2 hours to obtain polyketone / nylon 6 nanocomposite material.

[0020] The high crystallinity of the polyketone backbone endows the material with high rigidity, while the amide bonds in the nylon 6 molecular chain enhance the material's resilience through hydrogen bonding. The maleic anhydride groups react chemically with the amino groups of nylon 6 to form covalent bonds, thereby improving the interfacial bonding strength of the polymer and preventing the delamination failure of multi-component materials. The styrene-ethylene / butene-styrene block copolymer elastomer phase is physically entangled and dispersed in the polyketone / nylon 6 matrix, further enhancing the material's mechanical properties. In addition, the hydroxyl groups on the surface of cellulose nanocrystals form a hydrogen bond network with nylon 6, enhancing tensile strength, and forming a "brick-and-mortar" structure through nanoscale dispersion, effectively hindering crack propagation paths.

[0021] Preferably, the preparation steps of the cellulose nanocrystal dispersion are as follows: 3-5% of the mass of the polyketone / nylon 6 nanocomposite material is mixed with a polyvinylpyrrolidone aqueous solution with a concentration of 0.01-0.05 mol / L, and ultrasonically treated with a power of 400-500W for 20-30 minutes to obtain the cellulose nanocrystal dispersion.

[0022] Preferably, the amount of dicumyl peroxide added is 0.1-0.3% of the mass of the polyketone / nylon 6 nanocomposite material.

[0023] Secondly, the present invention provides a method for preparing a high-stiffness, high-resilience nylon composite material for a lumbar support chair, which is used in any one of the above-mentioned high-stiffness, high-resilience nylon composite materials for a lumbar support chair, comprising the following steps:

[0024] S1.1 Weigh the above-mentioned parts by weight of raw materials respectively;

[0025] S1.2 Add the weighed raw materials to a twin-screw extruder, set the temperature to 200-240℃, the screw speed to 200-300rpm, and the extrusion pressure to -0.05~-0.08MPa; granulate the melt using a pelletizer, dry it at 60-80℃ for 3-4h, and anneal it at 100-110℃ for 1-2h to obtain a high-rigidity, high-resilience nylon composite material for lumbar support chairs.

[0026] Thirdly, the present invention provides an application of a high-rigidity, high-resilience nylon composite material for a lumbar support chair, which adopts the following technical solution: the application of the above-mentioned high-rigidity, high-resilience nylon composite material for a lumbar support chair in the preparation of a lumbar support chair.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] 1. This invention relates to a high-rigidity, high-resilience nylon composite material for lumbar support chairs, its preparation method, and its application. By introducing bis-[3-(triethoxysilane)propyl]tetrasulfide onto the surface of glass fibers, chemical bonds are formed, significantly improving the interfacial adhesion between the glass fibers and the nylon 6 matrix. This effectively reduces fiber debonding, thereby enhancing the overall rigidity of the material and preventing collapse. Simultaneously, the addition of a nano-zinc oxide coating inhibits the propagation of microcracks and improves the material's fatigue resistance. This composite material not only maintains high rigidity but also possesses excellent resilience and durability, resisting deformation during long-term use and quickly restoring its shape.

[0029] 2. This high-rigidity, high-resilience nylon composite material for lumbar support chairs, its preparation method, and its application: Through the copolymerization and grafting structure of polyketone and nylon 6, the material combines the high rigidity of polyketone with the toughness of nylon 6; the introduction of maleic anhydride grafted onto styrene-ethylene / butene-styrene block copolymer effectively improves the phase separation problem between polyketone and nylon 6, while the addition of cellulose nanocrystals further enhances the interfacial bonding force; in addition, the unique nanocomposite structure can effectively disperse stress, ensuring that the material maintains good resilience after repeated stress. Detailed Implementation

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0031] This invention provides a high-rigidity, high-resilience nylon composite material for a lumbar support chair, comprising the following raw materials: polyketone / nylon 6 nanocomposite material, zinc oxide, modified glass fiber, glass microspheres, ethylene bis-stearamide, N,N'-hexane-1,6-dimethylbis[3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide], and titanium dioxide;

[0032] The following embodiments are used:

[0033] The glass microspheres used are high-performance glass microspheres from Hainuo, with a particle size of 45μm;

[0034] The titanium dioxide used is Helian titanium dioxide with a particle size of 0.42μm;

[0035] The CAS number for zinc oxide is 1314-13-2;

[0036] The glass fiber has a diameter of 10μm, a length of 4.5nm, and CAS number 65997-17-3.

[0037] Modified glass fiber is prepared by hydrolysis and condensation reaction of bis-[3-(triethoxysilyl)propyl]tetrasulfide with glass fiber, followed by deposition of nano-zinc oxide on its surface;

[0038] The polyketone / nylon 6 nanocomposite material is prepared by reacting polyketone with nylon 6 to generate a polyketone-grafted nylon 6 copolymer, and then grafting maleic anhydride and cellulose nanocrystals onto a styrene-ethylene / butene-styrene block copolymer.

[0039] Pre-treated glass fiber: Immerse the glass fiber in acetone and sonicate it at 300W for 30 minutes to remove the surface wetting agent; rinse it three times with deionized water and vacuum dry it at 80℃ for 12 hours; immerse the dried glass fiber in a 5% sodium hydroxide solution (60℃, 1 hour); after soaking, wash it with deionized water until neutral and dry it for later use.

[0040] Example 1: A method for preparing a high-stiffness, high-resilience nylon composite material for a lumbar support chair, comprising the following steps:

[0041] S1.1 Weigh the following raw materials in parts by weight: 60 parts by weight of polyketone / nylon 6 nanocomposite material, 0.5 parts by weight of zinc oxide, 15 parts by weight of modified glass fiber, 5 parts by weight of glass microspheres, 0.3 parts by weight of ethylene bis-stearamide, 0.2 parts by weight of N,N'-hexane-1,6-dimethylbis[3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide], and 1 part by weight of titanium dioxide;

[0042] S1.2 Add the weighed raw materials to a twin-screw extruder, set the temperature to 240℃, the screw speed to 300rpm, and the extrusion pressure to -0.08MPa; granulate the melt using a pelletizer, dry it at 80℃ for 4h, and anneal it at 100℃ for 2h to obtain a high-rigidity, high-resilience nylon composite material for lumbar support chairs.

[0043] The preparation method of modified glass fiber is as follows:

[0044] Bis-[3-(triethoxysilyl)propyl]tetrasulfide was mixed with 90% ethanol at a mass ratio of 1:4, the pH was adjusted to 5 with 0.5% acetic acid aqueous solution, and the mixture was stirred at 400 rpm for 45 min to obtain bis-[3-(triethoxysilyl)propyl]tetrasulfide hydrolysate.

[0045] The pretreated glass fiber was immersed in bis-[3-(triethoxysilyl)propyl]tetrasulfide hydrolysate at a solid-liquid ratio of 1:20 and reacted in a water bath at 60°C for 4 hours. After the reaction was completed, it was rinsed three times with ethanol and cured at 80°C for 1 hour to obtain bis-[3-(triethoxysilyl)propyl]tetrasulfide modified glass fiber.

[0046] Zinc acetate (0.05 mol / L) and hexamethylenetetramine (0.05 mol / L) were dissolved in 500 mL of deionized water at a molar ratio of 1:1. Polyvinylpyrrolidone (0.01 mol / L) was added, and the mixture was stirred at 300 rpm for 30 min to obtain zinc oxide sol.

[0047] The bis-[3-(triethoxysilyl)propyl]tetrasulfide modified glass fiber prepared above was immersed in zinc oxide sol and reacted at 100°C for 6 h. After the reaction was completed, it was washed three times with deionized water, dried at 100°C for 2 h, and annealed at 150°C for 1 h to obtain the modified glass fiber.

[0048] The preparation method of polyketone / nylon 6 nanocomposite material is as follows:

[0049] 3% of the mass of cellulose nanocrystals in the polyketone / nylon 6 nanocomposite were mixed with a 0.01 mol / L aqueous solution of polyvinylpyrrolidone and ultrasonically treated with a power of 500 W for 30 min to obtain a cellulose nanocrystal dispersion.

[0050] 8% (by mass) of the polyketone / nylon 6 nanocomposite material was dissolved in toluene to obtain a 5% (by mass) styrene-ethylene / butene-styrene block copolymer-grafted maleic anhydride solution. The above cellulose nanocrystal dispersion was added, and the mixture was stirred at 400 rpm for 2 hours at 60°C. After the reaction was completed, toluene was removed by rotary evaporation at 60°C to obtain composite particles of styrene-ethylene / butene-styrene block copolymer-grafted maleic anhydride-coated cellulose nanocrystals.

[0051] Polyketone / nylon 6 was premixed at a weight ratio of 6:4 and fed into a twin-screw extruder. Composite particles of styrene-ethylene / butene-styrene block copolymer grafted with maleic anhydride and cellulose nanocrystals were added, along with 0.1% dicumyl peroxide by mass of the polyketone / nylon 6 nanocomposite. The temperature was set at 235℃, the speed at 300 rpm, and the pressure at -0.08 MPa. The melt was granulated into particles with a diameter of 2 mm using a pelletizer, dried at 80℃ for 4 h, and annealed at 100℃ for 1 h to obtain the polyketone / nylon 6 nanocomposite.

[0052] Example 2: A method for preparing a high-stiffness, high-resilience nylon composite material for a lumbar support chair, comprising the following steps:

[0053] S1.1 Weigh the following raw materials in parts by weight: 70 parts by weight of polyketone / nylon 6 nanocomposite material, 1 part by weight of zinc oxide, 20 parts by weight of modified glass fiber, 8 parts by weight of glass microspheres, 0.5 parts by weight of ethylene bis-stearamide, 0.3 parts by weight of N,N'-hexane-1,6-dimethylbis[3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide], and 2 parts by weight of titanium dioxide;

[0054] S1.2 Add the weighed raw materials to a twin-screw extruder, set the temperature to 240℃, the screw speed to 300rpm, and the extrusion pressure to -0.08MPa; granulate the melt using a pelletizer, dry it at 80℃ for 4h, and anneal it at 100℃ for 2h to obtain a high-rigidity, high-resilience nylon composite material for lumbar support chairs.

[0055] The preparation method of modified glass fiber is as follows:

[0056] Bis-[3-(triethoxysilyl)propyl]tetrasulfide was mixed with 90% ethanol at a mass ratio of 1:4, the pH was adjusted to 5 with 0.5% acetic acid aqueous solution, and the mixture was stirred at 400 rpm for 45 min to obtain bis-[3-(triethoxysilyl)propyl]tetrasulfide hydrolysate.

[0057] The pretreated glass fiber was immersed in bis-[3-(triethoxysilyl)propyl]tetrasulfide hydrolysate at a solid-liquid ratio of 1:20 and reacted in a water bath at 60°C for 4 hours. After the reaction was completed, it was rinsed three times with ethanol and cured at 80°C for 1 hour to obtain bis-[3-(triethoxysilyl)propyl]tetrasulfide modified glass fiber.

[0058] Zinc acetate (0.05 mol / L) and hexamethylenetetramine (0.05 mol / L) were dissolved in 500 mL of deionized water at a molar ratio of 1:1. Polyvinylpyrrolidone (0.01 mol / L) was added, and the mixture was stirred at 300 rpm for 30 min to obtain zinc oxide sol.

[0059] The bis-[3-(triethoxysilyl)propyl]tetrasulfide modified glass fiber prepared above was immersed in zinc oxide sol and reacted at 100°C for 6 h. After the reaction was completed, it was washed three times with deionized water, dried at 100°C for 2 h, and annealed at 150°C for 1 h to obtain the modified glass fiber.

[0060] The preparation method of polyketone / nylon 6 nanocomposite material is as follows:

[0061] 3% of the mass of cellulose nanocrystals in the polyketone / nylon 6 nanocomposite were mixed with a 0.01 mol / L aqueous solution of polyvinylpyrrolidone and ultrasonically treated with a power of 500 W for 30 min to obtain a cellulose nanocrystal dispersion.

[0062] 8% (by mass) of the polyketone / nylon 6 nanocomposite material was dissolved in toluene to obtain a 5% (by mass) styrene-ethylene / butene-styrene block copolymer-grafted maleic anhydride solution. The above cellulose nanocrystal dispersion was added, and the mixture was stirred at 400 rpm for 2 hours at 60°C. After the reaction was completed, toluene was removed by rotary evaporation at 60°C to obtain composite particles of styrene-ethylene / butene-styrene block copolymer-grafted maleic anhydride-coated cellulose nanocrystals.

[0063] Polyketone / nylon 6 was premixed at a weight ratio of 6:4 and fed into a twin-screw extruder. Composite particles of styrene-ethylene / butene-styrene block copolymer grafted with maleic anhydride and cellulose nanocrystals were added, along with 0.1% dicumyl peroxide by mass of the polyketone / nylon 6 nanocomposite. The temperature was set at 235℃, the speed at 300 rpm, and the pressure at -0.08 MPa. The melt was granulated into particles with a diameter of 2 mm using a pelletizer, dried at 80℃ for 4 h, and annealed at 100℃ for 1 h to obtain the polyketone / nylon 6 nanocomposite.

[0064] Example 3: A method for preparing a high-stiffness, high-resilience nylon composite material for a lumbar support chair, comprising the following steps:

[0065] S1.1 Weigh the following raw materials in parts by weight: 65 parts by weight of polyketone / nylon 6 nanocomposite material, 0.8 parts by weight of zinc oxide, 17 parts by weight of modified glass fiber, 6 parts by weight of glass microspheres, 0.4 parts by weight of ethylene bis-stearamide, 0.25 parts by weight of N,N'-hexane-1,6-dimethylbis[3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide], and 1.5 parts by weight of titanium dioxide;

[0066] S1.2 Add the weighed raw materials to a twin-screw extruder, set the temperature to 240℃, the screw speed to 300rpm, and the extrusion pressure to -0.08MPa; granulate the melt using a pelletizer, dry it at 80℃ for 4h, and anneal it at 100℃ for 2h to obtain a high-rigidity, high-resilience nylon composite material for lumbar support chairs.

[0067] The preparation method of modified glass fiber is as follows:

[0068] Bis-[3-(triethoxysilyl)propyl]tetrasulfide was mixed with 90% ethanol at a mass ratio of 1:4, the pH was adjusted to 5 with 0.5% acetic acid aqueous solution, and the mixture was stirred at 400 rpm for 45 min to obtain bis-[3-(triethoxysilyl)propyl]tetrasulfide hydrolysate.

[0069] The pretreated glass fiber was immersed in bis-[3-(triethoxysilyl)propyl]tetrasulfide hydrolysate at a solid-liquid ratio of 1:20 and reacted in a water bath at 60°C for 4 hours. After the reaction was completed, it was rinsed three times with ethanol and cured at 80°C for 1 hour to obtain bis-[3-(triethoxysilyl)propyl]tetrasulfide modified glass fiber.

[0070] Zinc acetate (0.05 mol / L) and hexamethylenetetramine (0.05 mol / L) were dissolved in 500 mL of deionized water at a molar ratio of 1:1. Polyvinylpyrrolidone (0.01 mol / L) was added, and the mixture was stirred at 300 rpm for 30 min to obtain zinc oxide sol.

[0071] The bis-[3-(triethoxysilyl)propyl]tetrasulfide modified glass fiber prepared above was immersed in zinc oxide sol and reacted at 100°C for 6 h. After the reaction was completed, it was washed three times with deionized water, dried at 100°C for 2 h, and annealed at 150°C for 1 h to obtain the modified glass fiber.

[0072] The preparation method of polyketone / nylon 6 nanocomposite material is as follows:

[0073] 3% of the mass of cellulose nanocrystals in the polyketone / nylon 6 nanocomposite were mixed with a 0.01 mol / L aqueous solution of polyvinylpyrrolidone and ultrasonically treated with a power of 500 W for 30 min to obtain a cellulose nanocrystal dispersion.

[0074] 8% (by mass) of the polyketone / nylon 6 nanocomposite material was dissolved in toluene to obtain a 5% (by mass) styrene-ethylene / butene-styrene block copolymer-grafted maleic anhydride solution. The above cellulose nanocrystal dispersion was added, and the mixture was stirred at 400 rpm for 2 hours at 60°C. After the reaction was completed, toluene was removed by rotary evaporation at 60°C to obtain composite particles of styrene-ethylene / butene-styrene block copolymer-grafted maleic anhydride-coated cellulose nanocrystals.

[0075] Polyketone / nylon 6 was premixed at a weight ratio of 6:4 and fed into a twin-screw extruder. Composite particles of styrene-ethylene / butene-styrene block copolymer grafted with maleic anhydride and cellulose nanocrystals were added, along with 0.1% dicumyl peroxide by mass of the polyketone / nylon 6 nanocomposite. The temperature was set at 235℃, the speed at 300 rpm, and the pressure at -0.08 MPa. The melt was granulated into particles with a diameter of 2 mm using a pelletizer, dried at 80℃ for 4 h, and annealed at 100℃ for 1 h to obtain the polyketone / nylon 6 nanocomposite.

[0076] Example 4: A method for preparing a high-stiffness, high-resilience nylon composite material for a lumbar support chair, comprising the following steps:

[0077] S1.1 Weigh the following raw materials in parts by weight: 55 parts by weight of polyketone / nylon 6 nanocomposite material, 0.8 parts by weight of zinc oxide, 17 parts by weight of modified glass fiber, 6 parts by weight of glass microspheres, 0.4 parts by weight of ethylene bis-stearamide, 0.25 parts by weight of N,N'-hexane-1,6-dimethylbis[3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide], and 1.5 parts by weight of titanium dioxide;

[0078] S1.2 Add the weighed raw materials to a twin-screw extruder, set the temperature to 240℃, the screw speed to 300rpm, and the extrusion pressure to -0.08MPa; granulate the melt using a pelletizer, dry it at 80℃ for 4h, and anneal it at 100℃ for 2h to obtain a high-rigidity, high-resilience nylon composite material for lumbar support chairs.

[0079] The preparation method of modified glass fiber is as follows:

[0080] Bis-[3-(triethoxysilyl)propyl]tetrasulfide was mixed with 90% ethanol at a mass ratio of 1:4, the pH was adjusted to 5 with 0.5% acetic acid aqueous solution, and the mixture was stirred at 400 rpm for 45 min to obtain bis-[3-(triethoxysilyl)propyl]tetrasulfide hydrolysate.

[0081] The pretreated glass fiber was immersed in bis-[3-(triethoxysilyl)propyl]tetrasulfide hydrolysate at a solid-liquid ratio of 1:20 and reacted in a water bath at 60°C for 4 hours. After the reaction was completed, it was rinsed three times with ethanol and cured at 80°C for 1 hour to obtain bis-[3-(triethoxysilyl)propyl]tetrasulfide modified glass fiber.

[0082] Zinc acetate (0.05 mol / L) and hexamethylenetetramine (0.05 mol / L) were dissolved in 500 mL of deionized water at a molar ratio of 1:1. Polyvinylpyrrolidone (0.01 mol / L) was added, and the mixture was stirred at 300 rpm for 30 min to obtain zinc oxide sol.

[0083] The bis-[3-(triethoxysilyl)propyl]tetrasulfide modified glass fiber prepared above was immersed in zinc oxide sol and reacted at 100°C for 6 h. After the reaction was completed, it was washed three times with deionized water, dried at 100°C for 2 h, and annealed at 150°C for 1 h to obtain the modified glass fiber.

[0084] The preparation method of polyketone / nylon 6 nanocomposite material is as follows:

[0085] 3% of the mass of cellulose nanocrystals in the polyketone / nylon 6 nanocomposite were mixed with a 0.01 mol / L aqueous solution of polyvinylpyrrolidone and ultrasonically treated with a power of 500 W for 30 min to obtain a cellulose nanocrystal dispersion.

[0086] 8% (by mass) of the polyketone / nylon 6 nanocomposite material was dissolved in toluene to obtain a 5% (by mass) styrene-ethylene / butene-styrene block copolymer-grafted maleic anhydride solution. The above cellulose nanocrystal dispersion was added, and the mixture was stirred at 400 rpm for 2 hours at 60°C. After the reaction was completed, toluene was removed by rotary evaporation at 60°C to obtain composite particles of styrene-ethylene / butene-styrene block copolymer-grafted maleic anhydride-coated cellulose nanocrystals.

[0087] Polyketone / nylon 6 was premixed at a weight ratio of 6:4 and fed into a twin-screw extruder. Composite particles of styrene-ethylene / butene-styrene block copolymer grafted with maleic anhydride and cellulose nanocrystals were added, along with 0.1% dicumyl peroxide by mass of the polyketone / nylon 6 nanocomposite. The temperature was set at 235℃, the speed at 300 rpm, and the pressure at -0.08 MPa. The melt was granulated into particles with a diameter of 2 mm using a pelletizer, dried at 80℃ for 4 h, and annealed at 100℃ for 1 h to obtain the polyketone / nylon 6 nanocomposite.

[0088] Example 5: A method for preparing a high-stiffness, high-resilience nylon composite material for a lumbar support chair, comprising the following steps:

[0089] S1.1 Weigh the following raw materials in parts by weight: 65 parts by weight of polyketone / nylon 6 nanocomposite material, 0.8 parts by weight of zinc oxide, 10 parts by weight of modified glass fiber, 6 parts by weight of glass microspheres, 0.4 parts by weight of ethylene bis-stearamide, 0.25 parts by weight of N,N'-hexane-1,6-dimethylbis[3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide]], and 1.5 parts by weight of titanium dioxide;

[0090] S1.2 Add the weighed raw materials to a twin-screw extruder, set the temperature to 240℃, the screw speed to 300rpm, and the extrusion pressure to -0.08MPa; granulate the melt using a pelletizer, dry it at 80℃ for 4h, and anneal it at 100℃ for 2h to obtain a high-rigidity, high-resilience nylon composite material for lumbar support chairs.

[0091] The preparation method of modified glass fiber is as follows:

[0092] Bis-[3-(triethoxysilyl)propyl]tetrasulfide was mixed with 90% ethanol at a mass ratio of 1:4, the pH was adjusted to 5 with 0.5% acetic acid aqueous solution, and the mixture was stirred at 400 rpm for 45 min to obtain bis-[3-(triethoxysilyl)propyl]tetrasulfide hydrolysate.

[0093] The pretreated glass fiber was immersed in bis-[3-(triethoxysilyl)propyl]tetrasulfide hydrolysate at a solid-liquid ratio of 1:20 and reacted in a water bath at 60°C for 4 hours. After the reaction was completed, it was rinsed three times with ethanol and cured at 80°C for 1 hour to obtain bis-[3-(triethoxysilyl)propyl]tetrasulfide modified glass fiber.

[0094] Zinc acetate (0.05 mol / L) and hexamethylenetetramine (0.05 mol / L) were dissolved in 500 mL of deionized water at a molar ratio of 1:1. Polyvinylpyrrolidone (0.01 mol / L) was added, and the mixture was stirred at 300 rpm for 30 min to obtain zinc oxide sol.

[0095] The bis-[3-(triethoxysilyl)propyl]tetrasulfide modified glass fiber prepared above was immersed in zinc oxide sol and reacted at 100°C for 6 h. After the reaction was completed, it was washed three times with deionized water, dried at 100°C for 2 h, and annealed at 150°C for 1 h to obtain the modified glass fiber.

[0096] The preparation method of polyketone / nylon 6 nanocomposite material is as follows:

[0097] 3% of the mass of cellulose nanocrystals in the polyketone / nylon 6 nanocomposite were mixed with a 0.01 mol / L aqueous solution of polyvinylpyrrolidone and ultrasonically treated with a power of 500 W for 30 min to obtain a cellulose nanocrystal dispersion.

[0098] 8% (by mass) of the polyketone / nylon 6 nanocomposite material was dissolved in toluene to obtain a 5% (by mass) styrene-ethylene / butene-styrene block copolymer-grafted maleic anhydride solution. The above cellulose nanocrystal dispersion was added, and the mixture was stirred at 400 rpm for 2 hours at 60°C. After the reaction was completed, toluene was removed by rotary evaporation at 60°C to obtain composite particles of styrene-ethylene / butene-styrene block copolymer-grafted maleic anhydride-coated cellulose nanocrystals.

[0099] Polyketone / nylon 6 was premixed at a weight ratio of 6:4 and fed into a twin-screw extruder. Composite particles of styrene-ethylene / butene-styrene block copolymer grafted with maleic anhydride and cellulose nanocrystals were added, along with 0.1% dicumyl peroxide by mass of the polyketone / nylon 6 nanocomposite. The temperature was set at 235℃, the speed at 300 rpm, and the pressure at -0.08 MPa. The melt was granulated into particles with a diameter of 2 mm using a pelletizer, dried at 80℃ for 4 h, and annealed at 100℃ for 1 h to obtain the polyketone / nylon 6 nanocomposite.

[0100] Example 6: A method for preparing a high-stiffness, high-resilience nylon composite material for a lumbar support chair, comprising the following steps:

[0101] S1.1 Weigh the following raw materials in parts by weight: 65 parts by weight of polyketone / nylon 6 nanocomposite material, 0.8 parts by weight of zinc oxide, 17 parts by weight of modified glass fiber, 6 parts by weight of glass microspheres, 0.4 parts by weight of ethylene bis-stearamide, 0.25 parts by weight of N,N'-hexane-1,6-dimethylbis[3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide], and 1.5 parts by weight of titanium dioxide;

[0102] S1.2 Add the weighed raw materials to a twin-screw extruder, set the temperature to 240℃, the screw speed to 300rpm, and the extrusion pressure to -0.08MPa; granulate the melt using a pelletizer, dry it at 80℃ for 4h, and anneal it at 100℃ for 2h to obtain a high-rigidity, high-resilience nylon composite material for lumbar support chairs.

[0103] The preparation method of modified glass fiber is as follows:

[0104] Bis-[3-(triethoxysilyl)propyl]tetrasulfide was mixed with 90% ethanol at a mass ratio of 1:4, the pH was adjusted to 5 with 0.5% acetic acid aqueous solution, and the mixture was stirred at 400 rpm for 45 min to obtain bis-[3-(triethoxysilyl)propyl]tetrasulfide hydrolysate.

[0105] The pretreated glass fiber was immersed in bis-[3-(triethoxysilyl)propyl]tetrasulfide hydrolysate at a solid-liquid ratio of 1:20 and reacted in a water bath at 60°C for 4 hours. After the reaction was completed, it was rinsed three times with ethanol and cured at 80°C for 1 hour to obtain bis-[3-(triethoxysilyl)propyl]tetrasulfide modified glass fiber.

[0106] Zinc acetate (0.05 mol / L) and hexamethylenetetramine (0.05 mol / L) were dissolved in 500 mL of deionized water at a molar ratio of 1:1. Polyvinylpyrrolidone (0.01 mol / L) was added, and the mixture was stirred at 300 rpm for 30 min to obtain zinc oxide sol.

[0107] The bis-[3-(triethoxysilyl)propyl]tetrasulfide modified glass fiber prepared above was immersed in zinc oxide sol and reacted at 100°C for 6 h. After the reaction was completed, it was washed three times with deionized water, dried at 100°C for 2 h, and annealed at 150°C for 1 h to obtain the modified glass fiber.

[0108] The preparation method of polyketone / nylon 6 nanocomposite material is as follows:

[0109] 1% of the mass of cellulose nanocrystals in the polyketone / nylon 6 nanocomposite was mixed with a 0.01 mol / L aqueous solution of polyvinylpyrrolidone and ultrasonically treated with a power of 500 W for 30 min to obtain a cellulose nanocrystal dispersion.

[0110] 8% (by mass) of the polyketone / nylon 6 nanocomposite material was dissolved in toluene to obtain a 5% (by mass) styrene-ethylene / butene-styrene block copolymer-grafted maleic anhydride solution. The above cellulose nanocrystal dispersion was added, and the mixture was stirred at 400 rpm for 2 hours at 60°C. After the reaction was completed, toluene was removed by rotary evaporation at 60°C to obtain composite particles of styrene-ethylene / butene-styrene block copolymer-grafted maleic anhydride-coated cellulose nanocrystals.

[0111] Polyketone / nylon 6 was premixed at a weight ratio of 6:4 and fed into a twin-screw extruder. Composite particles of styrene-ethylene / butene-styrene block copolymer grafted with maleic anhydride and cellulose nanocrystals were added, along with 0.1% dicumyl peroxide by mass of the polyketone / nylon 6 nanocomposite. The temperature was set at 235℃, the speed at 300 rpm, and the pressure at -0.08 MPa. The melt was granulated into particles with a diameter of 2 mm using a pelletizer, dried at 80℃ for 4 h, and annealed at 100℃ for 1 h to obtain the polyketone / nylon 6 nanocomposite.

[0112] Comparative Example 1: Using the method of Example 3, in a high-stiffness, high-resilience nylon composite material for a lumbar support chair and its preparation method and application, bis-[3-(triethoxysilyl)propyl]tetrasulfide was not used to modify the glass fiber, and the glass fiber was used directly.

[0113] Comparative Example 2: Using the method of Example 3, in a high-rigidity, high-resilience nylon composite material for a lumbar support chair and its preparation method and application, polyketone / nylon 6 nanocomposite material was not used, and nylon 6 was used directly.

[0114] Comparative Example 3: Using the method of Example 3, in a high-rigidity, high-resilience nylon composite material for a lumbar support chair and its preparation method and application, no glass microspheres were added.

[0115] This invention relates to a high-stiffness, high-resilience nylon composite material for lumbar support chairs, prepared from polyketone / nylon 6 nanocomposite materials and modified glass fiber. The performance indicators and testing standards for this high-stiffness, high-resilience nylon composite material for lumbar support chairs are as follows:

[0116] Prepare dumbbell-shaped specimens according to standards. Condition the specimens in an environment with room temperature (20±2℃) and relative humidity of 50±10% for 4 hours to ensure stable environmental conditions. Fix the specimens on the grips of the tensile testing machine, apply pretension, and hold for 1-3 minutes to stabilize the specimens. Then, stretch the specimens to the set elongation (e.g., 5%) and hold for 1-3 minutes. After unloading, allow the specimens to relax naturally for 30 seconds, apply the same pretension again, and measure the remaining deformation length of the specimens. Calculate the springback rate according to the formula. A high springback rate indicates that the material can effectively absorb impact energy and recover quickly, avoiding a decrease in support force due to plastic deformation after prolonged use.

[0117] Prepare specimens according to standard requirements (80mm×10mm×4mm), and perform three-point bending tests using an electronic universal testing machine. The span of the testing machine is set to 16 times the specimen thickness (for example, for a 4mm thick specimen, the span is 64mm). The loading speed is usually 1-2mm / min until the specimen breaks. Calculate the bending strength according to the formula. A higher bending strength indicates that the composite material is less likely to bend or collapse under human body sitting pressure load.

[0118] Prepare dumbbell-shaped specimens according to the standard and conduct tests using an electronic universal testing machine under standard environmental conditions (23℃, 50% humidity) at a tensile rate of 5 mm / min. During the test, record the maximum load value reached by the specimen during the tensile process and the elongation at fracture. Calculate the tensile strength according to the formula.

[0119] The high-stiffness, high-resilience nylon composite materials for lumbar support chairs prepared in Examples 1-6 and Comparative Examples 1-3 were tested according to the above standards, and the data obtained are shown in Table 1:

[0120] Table 1 Performance data of the lumbar support chairs in Examples 1-6 and Comparative Examples 1-3

[0121]

[0122] Examples 1-3 and 4 show that: when other components in the nylon composite material for high-stiffness, high-resilience lumbar support chair remain unchanged, the resilience, flexural strength, and tensile strength of the lumbar support chair continuously improve when the weight of modified glass fiber increases; as a high-modulus reinforcing phase, the increased content of modified glass fiber directly improves the overall rigidity of the composite material; with the increase of fiber network density, the stress transmission path is more complete, allowing external forces to be more effectively dispersed through the fiber network; after the silane coupling agent modifies the surface of the glass fiber, strong chemical bonds (such as Si-OC / NH bonds) are formed between its surface and the matrix, significantly enhancing the interfacial bonding energy; the introduction of the nano-ZnO deposition layer produces a pinning effect, further improving the interfacial adhesion performance.

[0123] As can be seen from Examples 1-3 and Example 5, when the weight of polyketone / nylon 6 nanocomposite material for high-rigidity, high-resilience lumbar support chair remains unchanged, the resilience, bending strength and tensile strength of the lumbar support chair continuously increase when the weight of other components in the nylon composite material remains unchanged.

[0124] The carbonyl groups (C=O) on the polyketone molecular chain and the amide groups (-NH-CO-) of nylon 6 form a molecular-level interpenetrating network through hydrogen bonds and van der Waals forces, significantly improving the interfacial bonding strength. This strong interaction allows external loads to be uniformly distributed throughout the composite material, reducing stress concentration and thus improving tensile strength. The polyketone nanophase achieves ultrafine dispersion in the nylon 6 matrix and forms physicochemical crosslinking points through in-situ polymerization. As the polyketone content increases, the crosslinking density increases, molecular chain slip is hindered, and the flexural modulus is significantly improved. The interaction between polyketone and nylon 6 molecular chains leads to lattice distortion, hindering the rearrangement and breakage of molecular chain segments under stress. This effect is more pronounced at high temperatures, resulting in a higher flexural strength retention rate of the composite material.

[0125] Furthermore, as can be seen from Examples 3 and 6, as the proportion of cellulose nanocrystals increases, the resilience, flexural strength, and tensile strength of the lumbar support chair continuously improve. Because cellulose nanocrystals are rich in hydroxyl groups (-OH) on their surface, they can form a dense hydrogen bond network with the amide groups (-NH-CO-) in the nylon 6 matrix, thereby significantly enhancing the interfacial bonding strength. This strong interaction allows external loads to be evenly distributed throughout the composite material, reducing stress concentration and thus improving tensile strength. Cellulose nanocrystals also act as nucleating agents to promote the formation of a highly crystalline structure in the matrix. This microstructure preferentially absorbs energy through elastic phase deformation under flexural loads, thereby improving resilience. Simultaneously, cellulose nanocrystals hinder crack propagation by forming a three-dimensional network structure and dissipate energy through mechanisms such as fiber pull-out and slippage, further enhancing the impact resistance and toughness of the composite material.

[0126] Based on the above test experiments, Example 3 is considered the optimal example.

[0127] A comparison of Example 3 and Comparative Example 1 shows that in a high-stiffness, high-resilience nylon composite material for a lumbar support chair and its preparation method and application, without modifying the glass fiber with bis-[3-(triethoxysilyl)propyl]tetrasulfide, the bending strength and tensile strength of the lumbar support chair are significantly reduced when glass fiber is used directly. This is mainly due to insufficient interfacial bonding strength between the glass fiber and the nylon 6 matrix, leading to debonding and thus failing to effectively transfer stress. In addition, the direct use of glass fiber leads to fiber agglomeration or disordered distribution, further reducing the reinforcement efficiency.

[0128] A comparison of Example 3 and Comparative Example 2 shows that in a high-stiffness, high-resilience nylon composite material for a lumbar support chair, and its preparation method and application, when nylon 6 is used directly without the use of polyketone / nylon 6 nanocomposite material, the resilience, flexural strength, and tensile strength of the lumbar support chair are significantly reduced. This is because the molecular chains of pure nylon 6 mainly rely on hydrogen bonds and van der Waals forces for bonding, lacking the support of the interfacial strengthening mechanism found in nanocomposite materials. In contrast, the polyketone / nylon 6 nanocomposite material forms a hydrogen bond network between the carbonyl groups of polyketone and the amide groups of nylon, significantly improving the interfacial bonding strength. Furthermore, polyketone, as a nucleating agent, can increase the crystallinity of nylon 6, while the low crystallinity of pure nylon 6 results in lower flexural modulus and tensile strength compared to the modified material.

[0129] A comparison of Example 3 and Comparative Example 3 shows that in a high-rigidity, high-resilience nylon composite material for a lumbar support chair, its preparation method, and its application, the bending strength and tensile strength of the lumbar support chair are significantly reduced without the addition of glass microspheres. Glass microspheres, as rigid fillers, form a three-dimensional reinforcing skeleton in the nylon matrix, which can improve bending and tensile strength. Without glass microspheres, the matrix lacks rigid support, leading to a decrease in bending strength. Simultaneously, the hydrogen bonds and van der Waals forces between nylon molecular chains are difficult to effectively transfer loads, resulting in a significant decrease in bending modulus and tensile elastic modulus. Glass microspheres, as nucleating agents, can improve the crystallinity of nylon, and the crystalline regions act as a rigid skeleton to support mechanical properties.

[0130] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A nylon composite material for a high-rigidity, high-resilience lumbar support chair, characterized in that, The raw materials include: 60-70 parts by weight of polyketone / nylon 6 nanocomposite material, 0.5-1 parts by weight of zinc oxide, 15-20 parts by weight of modified glass fiber, 5-8 parts by weight of glass microspheres, 0.3-0.5 parts by weight of ethylene bis-stearamide, 0.2-0.3 parts by weight of N,N'-hexane-1,6-dimethylbis[3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide]], and 1-2 parts by weight of titanium dioxide; the modified glass fiber is prepared by hydrolyzing and condensing bis-[3-(triethoxysilyl)propyl]tetrasulfide with glass fiber and depositing nano zinc oxide on its surface; the polyketone / nylon 6 nanocomposite material is prepared by reacting polyketone with nylon 6 to generate polyketone-grafted nylon 6 copolymer, and then grafting maleic anhydride and cellulose nanocrystals onto styrene-ethylene / butene-styrene block copolymer.

2. The nylon composite material for a high-rigidity, high-resilience lumbar support chair according to claim 1, characterized in that, The modified glass fiber is prepared as follows: Bis-[3-(triethoxysilyl)propyl]tetrasulfide is mixed with ethanol / water at a volume ratio of 9:1, the pH is adjusted to 4-5 with an aqueous acetic acid solution, and the mixture is stirred at 300-400 rpm for 30-45 min to obtain a hydrolysate of bis-[3-(triethoxysilyl)propyl]tetrasulfide; the pretreated glass fiber is immersed in the hydrolysate of bis-[3-(triethoxysilyl)propyl]tetrasulfide at a solid-liquid ratio of 1:20, and reacted in a water bath at 50-60℃ for 3-4 h; After the reaction is completed, the glass fiber is rinsed with ethanol 2-3 times and cured at 70-80℃ for 0.5-1h to obtain bis-[3-(triethoxysilyl)propyl]tetrasulfide modified glass fiber; the bis-[3-(triethoxysilyl)propyl]tetrasulfide modified glass fiber is immersed in zinc oxide sol and reacted at 100-110℃ for 4-6h; after the reaction is completed, the glass fiber is rinsed with deionized water 2-3 times, dried at 100-120℃ for 1-2h, and annealed at 150-200℃ for 1-1.5h to obtain modified glass fiber.

3. The nylon composite material for a high-rigidity, high-resilience lumbar support chair according to claim 2, characterized in that, The concentration of the acetic acid aqueous solution is 0.5-1%.

4. The nylon composite material for a high-rigidity, high-resilience lumbar support chair according to claim 2, characterized in that, The preparation steps of the zinc oxide sol are as follows: zinc acetate with a concentration of 0.05-0.1 mol / L and hexamethylenetetramine with a concentration of 0.05-0.1 mol / L are dissolved in deionized water at a molar ratio of 1:1, and polyvinylpyrrolidone with a concentration of 0.01-0.05 mol / L is added. The mixture is stirred at a speed of 200-300 rpm for 15-30 min to obtain zinc oxide sol.

5. The nylon composite material for a high-rigidity, high-resilience lumbar support chair according to claim 1, characterized in that, The preparation method of the polyketone / nylon 6 nanocomposite material is as follows: 8-10% (by mass) of styrene-ethylene / butene-styrene block copolymer grafted with maleic anhydride is dissolved in toluene, and a cellulose nanocrystal dispersion is added. The mixture is stirred at 300-400 rpm for 1-2 hours at 50-60°C. After the reaction is complete, toluene is removed by rotary evaporation at 50-60°C to obtain composite particles of styrene-ethylene / butene-styrene block copolymer grafted with maleic anhydride and coated with cellulose nanocrystals. Polyketone / nylon 6 was premixed at a weight ratio of 6:4 and fed into a twin-screw extruder. Composite particles of styrene-ethylene / butene-styrene block copolymer grafted with maleic anhydride and coated with cellulose nanocrystals and dicumyl peroxide were added. The temperature was set at 200-235℃, the speed at 200-300 rpm, and the pressure at -0.05~-0.08 MPa. The melt was granulated by a pelletizer, dried at 60-80℃ for 3-4 hours, and annealed at 100-110℃ for 1-2 hours to obtain polyketone / nylon 6 nanocomposite material.

6. The nylon composite material for a high-rigidity, high-resilience lumbar support chair according to claim 5, characterized in that, The preparation steps of the cellulose nanocrystal dispersion are as follows: 3-5% of the mass of the polyketone / nylon 6 nanocomposite material is mixed with a polyvinylpyrrolidone aqueous solution with a concentration of 0.01-0.05 mol / L, and ultrasonically treated with a power of 400-500W for 20-30 minutes to obtain the cellulose nanocrystal dispersion.

7. The nylon composite material for a high-rigidity, high-resilience lumbar support chair according to claim 5, characterized in that, The amount of dicumyl peroxide added is 0.1-0.3% of the mass of the polyketone / nylon 6 nanocomposite material.

8. A method for preparing a high-stiffness, high-resilience nylon composite material for a lumbar support chair, used to prepare the high-stiffness, high-resilience nylon composite material for a lumbar support chair as described in any one of claims 1-7, characterized in that, The preparation method is as follows: S1.1 Weigh the above-mentioned raw materials in parts by weight; S1.2 Add the weighed raw materials to a twin-screw extruder, set the temperature to 200-240℃, the screw speed to 200-300rpm, and the extrusion pressure to -0.05~-0.08MPa; granulate the melt using a pelletizer, dry it at 60-80℃ for 3-4h, and anneal it at 100-110℃ for 1-2h to obtain a high-rigidity, high-resilience nylon composite material for lumbar support chairs.

9. The application of a high-rigidity, high-resilience nylon composite material for a lumbar support chair as described in claims 1-7 in the manufacture of a lumbar support chair.

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