Carbon-based stone-plastic composite packing material based on industrial solid waste as well as preparation method and application of carbon-based stone-plastic composite packing material

Abstract

The invention relates to the technical field of preparation of composite packing materials, and particularly discloses a carbon-based stone-plastic composite packing material based on industrial solid waste as well as a preparation method and application of the carbon-based stone-plastic composite packing material. Comprising the following steps: S1, preparing the following raw materials in parts by weight: 90-96 parts of polyvinyl chloride, 5-10 parts of functionalized core-shell particles, 8-10 parts of sulfhydrylated bamboo fibers, 0.8-1.2 parts of a lubricant, 1.5-3.5 parts of a heat stabilizer, 0.2-0.4 part of a photoinitiator and 10-12 parts of an organic solvent; s2, preparing a mixed material; functionalized core-shell particles and sulfhydrylated bamboo fibers are added, outer layers of the functionalized core-shell particles are prepared by modifying titanium dioxide structures through KH-560 and then chemically bonding the modified titanium dioxide structures with alpha-methylcinnamic acid, cores are pretreated coal gangue, and the pretreated coal gangue not only has high specific surface area and active hydroxyl, but also can be chemically bonded with the sulfhydrylated bamboo fibers, so that the specific surface area of the core-shell particles is increased, and the specific surface area of the core-shell particles is increased. Heavy metal ions in the composite packing material can be effectively adsorbed, and the mechanical property is improved.

Description

Technical Field

[0001] This invention relates to the field of composite packaging material preparation technology, and more specifically, to a carbon-based stone-plastic composite packaging material based on industrial solid waste, its preparation method, and its application. Background Technology

[0002] Due to outdated traditional mining methods and equipment, coal seam structures have become increasingly complex. Coal gangue, a waste product generated during coal mining, is stockpiled in large quantities, wasting land resources and posing significant safety hazards and environmental problems. This not only leads to substantial resource waste but also places a heavy burden on the natural environment and land resources. Therefore, there is an urgent need for the rational resource utilization of coal gangue slag. Existing research shows that the main components of coal gangue are similar to traditional mineral fillers, uniformly dispersed in polymers. The blended system not only possesses excellent physical properties but also extends to good functionality. Therefore, by fully utilizing industrial solid wastes such as fly ash and coal gangue, thoroughly mixing them with polyvinyl chloride and bamboo fiber, and then plasticizing and molding them after high-temperature and high-pressure melting, the resulting material can be widely used in various fields such as residential life and industrial and agricultural production.

[0003] However, coal gangue materials not only have large differences in molecular structure from polymer resins and bamboo fibers, resulting in poor mechanical properties of the prepared materials, but also contain excessive heavy metal ions, which are prone to leaching, thus limiting their further application.

[0004] Based on the above statements, the present invention provides a carbon-based stone-plastic composite packaging material based on industrial solid waste, its preparation method and application. Summary of the Invention

[0005] To address the problems mentioned in the background section, this invention provides a carbon-based stone-plastic composite packaging material based on industrial solid waste, its preparation method, and its application.

[0006] A method for preparing a carbon-based stone-plastic composite packaging material based on industrial solid waste includes the following steps: Step S1: Prepare the following raw materials by weight: 90-96 parts polyvinyl chloride, 5-10 parts functionalized core-shell particles, 8-10 parts mercaptoized bamboo fiber, 0.8-1.2 parts lubricant, 1.5-3.5 parts heat stabilizer, 0.2-0.4 parts photoinitiator and 10-12 parts organic solvent; Step S2, Mixing and Preparation: Polyvinyl chloride, functionalized core-shell particles, mercaptoized bamboo fiber, lubricant, heat stabilizer and photoinitiator are added to an organic solvent, heated to reflux temperature, stirred evenly, cooled to room temperature, irradiated with ultraviolet light for 14-18 minutes, evaporated under reduced pressure, and then extruded through a twin-screw extruder to obtain carbon-based stone-plastic composite packaging material based on industrial solid waste. The functionalized core-shell particles are first obtained by acid washing of coal gangue to obtain pretreated coal gangue, which is then subjected to alcohol dispersion hydrolysis reaction with tetrabutyl titanate to obtain core-shell particles. They are then modified with KH-560 to obtain epoxy-based core-shell particles, and finally subjected to ring-opening reaction with α-methylcinnamic acid to obtain the final product. The thiolized bamboo fiber is first obtained by treating bamboo fiber with alkali to obtain pretreated bamboo fiber, then reacting it with epichlorohydrin through a nucleophilic substitution reaction to obtain epoxy-based bamboo fiber, and finally reacting it with 4,6-diamino-2-mercaptopyrimidine through a ring-opening reaction to obtain the final product.

[0007] Further, in step S2, the extrusion process parameters of the twin-screw extruder are: zone 1 170-185℃, zone 2 175-185℃, zone 3 175-185℃, zone 4 170-180℃, zone 5 170-180℃, die head temperature 180℃; screw speed 15-35 rpm.

[0008] Further, in step S1, the lubricant is at least one of polyethylene wax, oxidized polyethylene wax, and monoglyceride.

[0009] Furthermore, in step S1, the heat stabilizer is a calcium-zinc composite stabilizer or a barium-zinc composite stabilizer.

[0010] Furthermore, in step S1, the photoinitiator is benzoin dimethyl ether.

[0011] Furthermore, in step S1, the organic solvent is anhydrous tetrahydrofuran.

[0012] Furthermore, the ultraviolet irradiation has a wavelength of 365 nm and an intensity of 80 mW / cm². 2 .

[0013] Furthermore, the functionalized core-shell particles are prepared by the following steps: Step A1: Crush and sieve the coal gangue to a particle size of 150-180μm, then acid wash with hydrochloric acid solution, filter, wash, dry, crush a second time, and sieve to obtain pretreated coal gangue. Step A2: Add pretreated coal gangue to an ethanol aqueous solution, ultrasonically disperse it evenly, add tetrabutyl titanate dropwise while stirring, stir for 1.8-2.2 h, then add deionized water dropwise, continue stirring for 3.8-4.2 h, filter, wash, dry, pulverize, and calcine to obtain core-shell particles. In the above reaction process, core-shell particles with titanium dioxide shell and pretreated coal gangue core are prepared by alcohol dispersion hydrolysis method. Step A3: Ultrasonically mix the core-shell particles, deionized water, anhydrous ethanol, and KH-560 until homogeneous. Heat to 48-56℃ and continue stirring for 5.2-5.8 hours. Centrifuge, wash, and dry to obtain epoxy-based core-shell particles. Ultrasonically disperse the epoxy-based core-shell particles and anhydrous DMF until homogeneous. Dropwise add a mixture of tetrabutylammonium bromide, α-methylcinnamic acid, and anhydrous DMF. After the addition is complete, heat to 92-96℃ and stir for 2.2-2.8 hours. Centrifuge, wash, and dry to obtain functionalized core-shell particles.

[0014] Furthermore, in step A1, the specific process parameters for pickling are: the mass fraction of hydrochloric acid aqueous solution is 8-12%, the pickling temperature is 40-60℃, and the pickling time is 0.5-0.8h.

[0015] Furthermore, in step A2, the mass fraction of the ethanol aqueous solution is 16-20%.

[0016] Further, in step A2, the mass ratio of pretreated coal gangue, ethanol aqueous solution, tetrabutyl titanate and deionized water is 2.2-2.8:280-320:6-8:140-160.

[0017] Furthermore, in step A2, the calcination temperature is 460-480℃ and the calcination time is 1.6-1.8h.

[0018] Further, in step A3, the mass ratio of core-shell particles, deionized water, anhydrous ethanol, and KH-560 is 2.4-2.8:10:30-40:0.5-0.8; the mass ratio of epoxy-based core-shell particles, anhydrous DMF, and mixture a is 3:50-60:20; and in mixture a, the mass ratio of tetrabutylammonium bromide, α-methylcinnamic acid, and anhydrous DMF is 0.1:1-1.2:20.

[0019] Furthermore, the thiolized bamboo fiber is prepared by the following steps: Step B1: Wash the bamboo fiber with deionized water, dry it, then immerse it in sodium hydroxide aqueous solution and stir for 3.6-4.4 hours. Take it out, wash it, then place it in acetic acid aqueous solution and adjust the pH to 7. Take it out, wash it, and dry it to obtain pretreated bamboo fiber. Step B2: Add the pretreated bamboo fiber to anhydrous DMF, heat to 45-55℃, stir evenly, add epichlorohydrin dropwise, after the addition is complete, heat to 60-70℃, stir and react for 3-3.4h, distill under reduced pressure to obtain epoxy-based bamboo fiber. In the above reaction process, anhydrous DMF is used as solvent, and the active hydroxyl groups on the pretreated bamboo fiber undergo nucleophilic substitution reaction with the chlorine atoms on the epichlorohydrin to obtain epoxy-based bamboo fiber. Step B3: Add epoxy-based bamboo fiber to anhydrous DMF and stir until homogeneous. While stirring, add a mixture of triethylamine, 4,6-diamino-2-mercaptopyrimidine, and anhydrous DMF (b) dropwise. After the addition is complete, heat to 102-106℃ and stir for 2.4-2.8 hours. Centrifuge, wash, and dry to obtain thiolated bamboo fiber. In the above reaction process, anhydrous DMF is used as the solvent. Under the catalysis of triethylamine, the epoxy groups on the epoxy-based bamboo fiber undergo a ring-opening reaction with the amino groups on the 4,6-diamino-2-mercaptopyrimidine to obtain thiolated bamboo fiber.

[0020] Furthermore, in step B1, the mass fraction of the sodium hydroxide aqueous solution is 0.6-0.8%.

[0021] Furthermore, in step B1, the mass fraction of the acetic acid aqueous solution is 3-5%.

[0022] Furthermore, in step B1, the mass ratio of bamboo fiber to sodium hydroxide aqueous solution is 1:40-50.

[0023] Furthermore, in step B2, the mass ratio of pretreated bamboo fiber, anhydrous DMF, and epichlorohydrin is 3-5:45-55:0.7-1.2.

[0024] Further, in step B3, the mass ratio of epoxy-based bamboo fiber, anhydrous DMF, and mixture b is 0.4-0.8:60-80:25-35, and in mixture b, the mass ratio of triethylamine, 4,6-diamino-2-mercaptopyrimidine, and anhydrous DMF is 0.04-0.08:0.3-0.5:20.

[0025] Application of a carbon-based stone-plastic composite packaging material based on industrial solid waste in the preparation of outer packaging boxes for fresh food cold chain logistics.

[0026] Compared with the prior art, the present invention has the following beneficial effects: To better adsorb heavy metal ions in carbon-based stone-plastic composite packaging materials and improve their mechanical properties, this invention addresses the issue from two aspects. First, it incorporates mercapto-modified bamboo fiber, which is prepared by chemically bonding epoxy-modified bamboo fiber and 4,6-diamino-2-mercaptopyrimidine. On one hand, the epoxy-modified bamboo fiber contains a flexible long-chain alkane structure, which not only entangles with polyvinyl chloride molecular chains to form an interpenetrating molecular network, but also forms hydrogen bonds with the oxygen-containing groups on functionalized core-shell particles, improving the mechanical properties of the carbon-based stone-plastic composite packaging material and enhancing its adsorption of metal ions. On the other hand, the 4,6-diamino-2-mercaptopyrimidine grafted onto the surface of the mercapto-modified bamboo fiber has a unique molecular structure that effectively adsorbs heavy metal ions from the carbon-based stone-plastic composite packaging material. The first step is to remove heavy metal ions. The second step involves the addition of functionalized core-shell particles. The outer layer of these particles is made of titanium dioxide modified with KH-560 and then chemically bonded with α-methylcinnamic acid. The core is pretreated coal gangue. On the one hand, the titanium dioxide structure can synergistically adsorb heavy metal ions in the carbon-based stone-plastic composite packaging material through its high specific surface area and active hydroxyl groups. On the other hand, the α-methylcinnamic acid grafted on the surface of the functionalized core-shell particles has a rigid benzene ring structure. The carboxyl groups on the ring can not only form hydrogen bonds with the amino groups on the mercaptoized bamboo fiber, but also form chemical bonds with the 4,6-diamino-2-mercaptopyrimidine on the mercaptoized bamboo fiber through a reaction. Through these actions, the heavy metal ions in the carbon-based stone-plastic composite packaging material can be better adsorbed, while improving its mechanical properties. Detailed Implementation

[0027] To make the embodiments of the present invention easier to understand, the present invention will be described in detail below with reference to specific embodiments. These embodiments are for illustrative purposes only and are not limited to the application scope of the present invention.

[0028] Where specific techniques or conditions are not specified in the examples, they shall be performed in accordance with the techniques or conditions described in the literature in this field, or in accordance with the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased through legitimate channels.

[0029] Polyvinyl chloride (PVC) was purchased from Shanghai Honglei Plastics Co., Ltd., grade EM-2070, processing grade: extrusion grade; polyethylene wax was purchased from Dongguan Fengtai Import & Export Co., Ltd., CAS number 9002-88-4; oxidized polyethylene wax was purchased from Qingdao Sainuo Chemical Co., Ltd., CAS number 68441-17-8, softening point: 100-105℃; mono-fatty acid glycerides were purchased from Nantong Zhonghe Chemical New Materials Co., Ltd., CAS number 123-94-4; calcium-zinc composite stabilizer was purchased from Shijiazhuang Junlong Chemical Products Sales Co., Ltd., item number JL-539; barium-zinc composite stabilizer was purchased from Nanxing Chemical (Jiangsu) Co., Ltd., melting point: 239-243℃; tetrabutyl titanate was purchased from Jinan Yuno Chemical Co., Ltd., CAS number 5593-70-4; coal gangue was purchased from Lingshou County Erping Mineral Products Processing Plant, its chemical composition is shown in Table 1; Table 1 Chemical composition of coal gangue (wt / %) The present invention will be further described in detail below with reference to embodiments and comparative examples.

[0030] Examples 1-3 and Comparative Examples 1-4 provide a carbon-based stone-plastic composite packaging material based on industrial solid waste, its preparation method, and its application.

[0031] Example 1 This embodiment provides a method for preparing carbon-based stone-plastic composite packaging material based on industrial solid waste, including the following steps: Step S1: Prepare the following raw materials by weight: 90 parts polyvinyl chloride, 5 parts functionalized core-shell particles, 8 parts mercapto-modified bamboo fiber, 0.8 parts polyethylene wax, 1.5 parts calcium-zinc composite stabilizer, 0.2 parts benzoin dimethyl ether and 10 parts anhydrous tetrahydrofuran; Step S2, Mixing Preparation: Polyvinyl chloride, functionalized core-shell particles, mercaptoized bamboo fiber, polyethylene wax, calcium-zinc composite stabilizer, and benzoin dimethyl ether are added to anhydrous tetrahydrofuran. The mixture is heated to reflux temperature and stirred at 700 rpm for 16 minutes until homogeneous. After cooling to room temperature, it is then placed in a container with a wavelength peak of 365 nm and an intensity of 80 mw / cm. 2 The material was irradiated with ultraviolet light for 14 minutes, then subjected to reduced pressure rotary evaporation at a controlled temperature of 40℃ for 0.6 hours. The resulting material was then extruded using a twin-screw extruder to obtain a carbon-based stone-plastic composite packaging material based on industrial solid waste. The extrusion process parameters of the twin-screw extruder were: zone 1 170℃, zone 2 175℃, zone 3 175℃, zone 4 170℃, zone 5 170℃, die head temperature 180℃, and screw speed 15 rpm. The functionalized core-shell particles are prepared by the following steps: Step A1: Crush and sieve the coal gangue to a particle size of 150 μm, then acid wash with hydrochloric acid aqueous solution, filter, and wash three times each with anhydrous ethanol and deionized water (each time the mass of anhydrous ethanol and deionized water is 20% of the mass of hydrochloric acid aqueous solution), dry at 60℃ to constant weight, crush a second time, and pass through a 420 mesh sieve to obtain pretreated coal gangue. The specific process parameters for acid washing are: mass fraction of hydrochloric acid aqueous solution is 8%, acid washing temperature is 40℃, and acid washing time is 0.5h. Step A2: Add the pretreated coal gangue to a 16% (w / w) ethanol aqueous solution. Disperse the mixture ultrasonically for 22 minutes at a frequency of 35 kHz and a power of 500 W until homogeneous. While stirring, add tetrabutyl titanate dropwise over 10 minutes at a rate of 3 drops / second. Maintain the stirring speed and continue stirring for 1.8 hours. Then add deionized water dropwise over 10 minutes at a rate of 3 drops / second. After the addition is complete, continue stirring for 3.8 hours. Filter the mixture and wash it three times each with anhydrous ethanol and deionized water (each time the amount of anhydrous ethanol and deionized water is 20% of the mass of the ethanol aqueous solution). Dry the mixture at 60°C to constant weight, pulverize, and calcine. Control the calcination temperature at 460°C and the calcination time for 1.6 hours to obtain core-shell particles. The mass ratio of pretreated coal gangue, ethanol aqueous solution, tetrabutyl titanate, and deionized water is 2.2:280:6:140. Step A3: The core-shell particles, deionized water, anhydrous ethanol, and KH-560 are ultrasonically mixed evenly at a frequency of 35 kHz, a power of 500 W, and a time of 16 min. The mixture is then heated to 48°C and stirred at 480 rpm for 5.2 h. After centrifugation at 6000 rpm for 10 min, the particles are washed three times with anhydrous ethanol (each time with deionized water at 15% of the ethanol mass). The mixture is then dried at 66°C to constant weight to obtain epoxy-based core-shell particles. The epoxy-based core-shell particles and anhydrous DMF are then ultrasonically dispersed evenly at a frequency of 35 kHz, a power of 500 W, and a time of 14 min. A mixture of tetrabutylammonium bromide, α-methylcinnamic acid, and anhydrous DMF (a) is then added dropwise. The addition was controlled to be completed within 10 minutes, with a dropping rate of 3 drops / second. After the addition was completed, the temperature was raised to 92℃, and the stirring speed was controlled at 600 rpm. The reaction was stirred for 2.2 hours, centrifuged at 7000 rpm for 12 minutes, and washed three times each with anhydrous ethanol and deionized water (each time the amount of anhydrous ethanol and deionized water was 20% of the mass of the ethanol-water solution). The mixture was dried at 64℃ to constant weight to obtain functionalized core-shell particles. The mass ratio of core-shell particles, deionized water, anhydrous ethanol and KH-560 was 2.4:10:30:0.5; the mass ratio of epoxy-based core-shell particles, anhydrous DMF and mixture a was 3:50:20. In mixture a, the mass ratio of tetrabutylammonium bromide, α-methylcinnamic acid and anhydrous DMF was 0.1:1:20. The thiolized bamboo fiber is prepared by the following steps: Step B1: Wash the bamboo fiber with deionized water, dry it at 50°C to constant weight, then immerse it in a 0.6% sodium hydroxide aqueous solution and stir for 3.6 hours. Remove it, wash it with deionized water, and then place it in a 3% acetic acid aqueous solution to adjust the pH to 7. Remove it, wash it with deionized water, and dry it at 60°C to constant weight to obtain pretreated bamboo fiber. The mass ratio of bamboo fiber to sodium hydroxide aqueous solution is 1:40. Step B2: Add the pretreated bamboo fiber to anhydrous DMF, heat to 45℃, control the speed at 500 rpm, stir for 18 min until uniform, add epichlorohydrin dropwise, control the dropwise addition to be completed within 10 min, with a dropwise acceleration rate of 3 drops / second, after the dropwise addition is completed, heat to 60℃, maintain the speed at a constant, continue stirring and reacting for 3 h, control the temperature of vacuum distillation to 76℃, the pressure of vacuum distillation to 0.8 kPa, vacuum distillation until anhydrous DMF is removed, to obtain epoxy-based bamboo fiber, wherein the mass ratio of pretreated bamboo fiber, anhydrous DMF and epichlorohydrin is 3:45:0.7; Step B3: Add epoxy-based bamboo fiber to anhydrous DMF and stir at 560 rpm for 22 min until homogeneous. While stirring, add triethylamine, 4,6-diamino-2-mercaptopyrimidine, and anhydrous DMF mixture b dropwise, controlling the addition to be completed within 10 min at a dropping rate of 3 drops / second. After the addition is complete, raise the temperature to 102℃ and stir for 2.4 h. Centrifuge at 6600 rpm for 14 min. Wash three times each with anhydrous ethanol and deionized water (each time the amount of anhydrous ethanol and deionized water is 10% of the mass of anhydrous DMF). Dry at 68℃ to constant weight to obtain mercapto-based bamboo fiber. The mass ratio of epoxy-based bamboo fiber, anhydrous DMF, and mixture b is 0.4:60:25. In mixture b, the mass ratio of triethylamine, 4,6-diamino-2-mercaptopyrimidine, and anhydrous DMF is 0.04:0.3:20.

[0032] Example 2 This embodiment provides a method for preparing carbon-based stone-plastic composite packaging material based on industrial solid waste, including the following steps: Step S1: Prepare the following raw materials by weight: 93 parts polyvinyl chloride, 7.5 parts functionalized core-shell particles, 9 parts mercaptoized bamboo fiber, 1 part oxidized polyethylene wax, 2.5 parts barium zinc composite stabilizer, 0.3 parts benzoin dimethyl ether and 11 parts anhydrous tetrahydrofuran. Step S2, Mixing Preparation: Polyvinyl chloride, functionalized core-shell particles, mercaptoized bamboo fiber, oxidized polyethylene wax, barium zinc composite stabilizer, and benzoin dimethyl ether are added to anhydrous tetrahydrofuran. The mixture is heated to reflux temperature and stirred at 750 rpm for 18 minutes until homogeneous. After cooling to room temperature, it is then placed in a container with a wavelength peak of 365 nm and an intensity of 80 mw / cm. 2 The material was irradiated with ultraviolet light for 16 minutes, then subjected to reduced pressure rotary evaporation at a controlled temperature of 45°C for 0.7 hours. The resulting material was then extruded using a twin-screw extruder to obtain a carbon-based stone-plastic composite packaging material based on industrial solid waste. The extrusion process parameters of the twin-screw extruder were: zone 1 178°C, zone 2 180°C, zone 3 180°C, zone 4 175°C, zone 5 175°C, die head temperature 180°C, and screw speed 25 rpm. The functionalized core-shell particles are prepared by the following steps: Step A1: Crush and sieve the coal gangue to a particle size of 165μm, then acid wash with hydrochloric acid aqueous solution, filter, and wash with anhydrous ethanol and deionized water 4 times each (each time the mass of anhydrous ethanol and deionized water is 20% of the mass of hydrochloric acid aqueous solution), dry at 64℃ to constant weight, crush a second time, and pass through a 440 mesh sieve to obtain pretreated coal gangue. The specific process parameters for acid washing are: mass fraction of hydrochloric acid aqueous solution is 10%, acid washing temperature is 50℃, and acid washing time is 0.65h. Step A2: Add the pretreated coal gangue to an 18% (w / w) ethanol aqueous solution and ultrasonically disperse it for 24 min until uniform at an ultrasonic frequency of 40 kHz and an ultrasonic power of 550 W. Control the rotation speed at 540 rpm and add tetrabutyl titanate dropwise while stirring, controlling the addition to be completed within 10 min at a dropping rate of 4 drops / second. After the addition is completed, maintain the rotation speed and stir for 2 h. Then add deionized water dropwise, controlling the addition to be completed within 10 min at a dropping rate of 4 drops / second. After the addition is completed, continue stirring for 4 h. Filter and wash with anhydrous ethanol and deionized water 4 times each (each time the amount of anhydrous ethanol and deionized water is 20% of the mass of the ethanol aqueous solution). Dry at 64℃ to constant weight, pulverize, and calcine. Control the calcination temperature at 470℃ and the calcination time at 1.7 h to obtain core-shell particles. The mass ratio of pretreated coal gangue, ethanol aqueous solution, tetrabutyl titanate, and deionized water is 2.5:300:7:150. Step A3: The core-shell particles, deionized water, anhydrous ethanol, and KH-560 are ultrasonically mixed until homogeneous. The ultrasonic frequency is controlled at 40 kHz, the ultrasonic power at 550 W, and the ultrasonic time at 18 min. The temperature is raised to 52℃, and the stirring speed is controlled at 500 rpm. Stirring continues for 5.5 h. Centrifugation is performed at 6500 rpm for 12 min. The particles are washed four times with anhydrous ethanol (each time the deionized water mass is 15% of the anhydrous ethanol mass). The particles are dried at 68℃ to constant weight to obtain epoxy-based core-shell particles. The epoxy-based core-shell particles and anhydrous DMF are ultrasonically dispersed until homogeneous. The ultrasonic frequency is controlled at 40 kHz, the ultrasonic power at 550 W, and the ultrasonic time at 16 min. Tetrabutylammonium bromide, α-methylcinnamic acid, and anhydrous DMF are added dropwise. Mixture a was added dropwise over 10 minutes at a rate of 4 drops / second. After the addition was complete, the temperature was raised to 94°C, and the mixture was stirred for 2.5 hours. The mixture was then centrifuged at 7400 rpm for 14 minutes. The mixture was washed four times each with anhydrous ethanol and deionized water (each time the amount of anhydrous ethanol and deionized water was 20% of the mass of the ethanol-water solution). The mixture was dried at 66°C to constant weight to obtain functionalized core-shell particles. The mass ratio of core-shell particles, deionized water, anhydrous ethanol, and KH-560 was 2.6:10:35:0.65. The mass ratio of epoxy-based core-shell particles, anhydrous DMF, and mixture a was 3:55:20. In mixture a, the mass ratio of tetrabutylammonium bromide, α-methylcinnamic acid, and anhydrous DMF was 0.1:1.1:20. The thiolized bamboo fiber is prepared by the following steps: Step B1: Wash the bamboo fiber with deionized water, dry it at 55°C, then immerse it in a 0.7% sodium hydroxide aqueous solution and stir for 4 hours. Remove it, wash it with deionized water, and then place it in a 4% acetic acid aqueous solution to adjust the pH to 7. Remove it, wash it with deionized water, and dry it at 62°C to constant weight to obtain pretreated bamboo fiber. The mass ratio of bamboo fiber to sodium hydroxide aqueous solution is 1:45. Step B2: Add the pretreated bamboo fiber to anhydrous DMF, heat to 50℃, control the rotation speed at 520 rpm, stir for 20 min until uniform, add epichlorohydrin dropwise, control the dropwise addition to be completed within 10 min, with a dropwise acceleration rate of 4 drops / second, after the dropwise addition is completed, heat to 65℃, maintain the rotation speed, and continue stirring for 3.2 h, control the vacuum distillation temperature at 78℃, the vacuum distillation pressure at 0.9 kPa, and distill under vacuum until the anhydrous DMF is removed to obtain epoxy-based bamboo fiber, wherein the mass ratio of pretreated bamboo fiber, anhydrous DMF and epichlorohydrin is 4:50:0.95; Step B3: Add epoxy-based bamboo fiber to anhydrous DMF and stir at 580 rpm for 24 min until homogeneous. While stirring, add triethylamine, 4,6-diamino-2-mercaptopyrimidine, and anhydrous DMF mixture b dropwise, controlling the addition to be completed within 10 min at a dropping rate of 4 drops / second. After the addition is complete, raise the temperature to 104℃ and stir for 2.6 h. Centrifuge at 6800 rpm for 16 min. Wash the mixture four times each with anhydrous ethanol and deionized water (each time the amount of anhydrous ethanol and deionized water is 10% of the mass of anhydrous DMF). Dry at 70℃ to constant weight to obtain thiolated bamboo fiber. The mass ratio of epoxy-based bamboo fiber, anhydrous DMF, and mixture b is 0.6:70:30. In mixture b, the mass ratio of triethylamine, 4,6-diamino-2-mercaptopyrimidine, and anhydrous DMF is 0.06:0.4:20.

[0033] Example 3 This embodiment provides a method for preparing carbon-based stone-plastic composite packaging material based on industrial solid waste, including the following steps: Step S1: Prepare the following raw materials by weight: 96 parts polyvinyl chloride, 10 parts functionalized core-shell particles, 10 parts mercaptoized bamboo fiber, 1.2 parts mono-fatty acid glycerides, 3.5 parts calcium-zinc composite stabilizer, 0.4 parts benzoin dimethyl ether, and 12 parts anhydrous tetrahydrofuran. Step S2, Mixing Preparation: Polyvinyl chloride, functionalized core-shell particles, mercaptoized bamboo fiber, mono-fatty acid glycerides, calcium-zinc composite stabilizer, and benzoin dimethyl ether are added to anhydrous tetrahydrofuran. The mixture is heated to reflux temperature and mixed at 800 rpm for 20 minutes until homogeneous. After cooling to room temperature, it is then placed in a container with a wavelength peak of 365 nm and an intensity of 80 mw / cm. 2The material was irradiated with ultraviolet light for 18 minutes, then subjected to reduced pressure rotary evaporation at a controlled temperature of 50°C for 0.8 hours. It was then extruded using a twin-screw extruder to obtain a carbon-based stone-plastic composite packaging material based on industrial solid waste. The extrusion process parameters of the twin-screw extruder were: zone 1 185°C, zone 2 185°C, zone 3 185°C, zone 4 180°C, zone 5 180°C, die head temperature 180°C, and screw speed 35 rpm. The functionalized core-shell particles are prepared by the following steps: Step A1: Crush and sieve the coal gangue to a particle size of 180 μm, then acid wash with hydrochloric acid aqueous solution, filter, and wash 5 times each with anhydrous ethanol and deionized water (each time the mass of anhydrous ethanol and deionized water is 20% of the mass of hydrochloric acid aqueous solution), dry at 68℃ to constant weight, crush a second time, and pass through a 460 mesh sieve to obtain pretreated coal gangue. The specific process parameters for acid washing are: mass fraction of hydrochloric acid aqueous solution of 12%, acid washing temperature of 60℃, and acid washing time of 0.8h. Step A2: Add the pretreated coal gangue to a 20% (w / w) ethanol aqueous solution. Disperse the mixture ultrasonically at a frequency of 45 kHz and a power of 600 W for 26 minutes until homogeneous. While stirring at 500 rpm, add tetrabutyl titanate dropwise over 10 minutes at a rate of 5 drops / second. After the addition is complete, maintain the stirring speed and continue stirring for 2.2 hours. Then add deionized water dropwise over 10 minutes at a rate of 5 drops / second. After the dripping was complete, the stirring speed was kept constant and the mixture was stirred for 4.2 hours. The mixture was then filtered and washed five times each with anhydrous ethanol and deionized water (each time the amount of anhydrous ethanol and deionized water was 20% of the mass of the ethanol-water solution). The mixture was dried at 68°C to constant weight, pulverized, and calcined. The calcination temperature was controlled at 480°C and the calcination time was 1.8 hours to obtain core-shell particles. The mass ratio of pretreated coal gangue, ethanol-water solution, tetrabutyl titanate, and deionized water was 2.8:320:8:160. Step A3: The core-shell particles, deionized water, anhydrous ethanol, and KH-560 are ultrasonically mixed uniformly at a frequency of 45 kHz, a power of 600 W, and a time of 20 min. The mixture is then heated to 56 °C and stirred at 520 rpm for 5.8 h. After centrifugation at 7000 rpm for 14 min, the mixture is washed five times with anhydrous ethanol (each time with deionized water at 15% of the anhydrous ethanol mass). The mixture is then dried at 70 °C to constant weight to obtain epoxy-based core-shell particles. The epoxy-based core-shell particles and anhydrous DMF are then ultrasonically dispersed uniformly at a frequency of 45 kHz, a power of 600 W, and a time of 18 min. Tetrabutylammonium bromide, α-methylcinnamic acid, and anhydrous DMF are then added dropwise. Mixture a was added dropwise over 10 minutes at a rate of 5 drops / second. After the addition was complete, the temperature was raised to 96°C, and the mixture was stirred for 2.8 hours. The mixture was then centrifuged at 7800 rpm for 16 minutes. The mixture was washed five times each with anhydrous ethanol and deionized water (each time the amount of anhydrous ethanol and deionized water was 20% of the mass of the ethanol-water solution). The mixture was dried at 68°C to constant weight to obtain functionalized core-shell particles. The mass ratio of core-shell particles, deionized water, anhydrous ethanol, and KH-560 was 2.8:10:40:0.8. The mass ratio of epoxy-based core-shell particles, anhydrous DMF, and mixture a was 3:60:20. In mixture a, the mass ratio of tetrabutylammonium bromide, α-methylcinnamic acid, and anhydrous DMF was 0.1:1.2:20. The thiolized bamboo fiber is prepared by the following steps: Step B1: Wash the bamboo fiber with deionized water, dry it at 60°C, then immerse it in a 0.8% sodium hydroxide aqueous solution and stir for 4.4 hours. Remove it, wash it with deionized water, and then place it in a 5% acetic acid aqueous solution to adjust the pH to 7. Remove it, wash it with deionized water, and dry it at 64°C to constant weight to obtain pretreated bamboo fiber. The mass ratio of bamboo fiber to sodium hydroxide aqueous solution is 1:50. Step B2: Add the pretreated bamboo fiber to anhydrous DMF, heat to 55℃, control the speed at 540 rpm, stir for 22 min until uniform, add epichlorohydrin dropwise, after the addition is complete, heat to 70℃, control the addition to be completed within 10 min, the dropping rate is 5 drops / second, maintain the speed constant, continue stirring and react for 3.4 h, control the temperature of vacuum distillation at 80℃, the pressure of vacuum distillation at 1.0 kPa, vacuum distillation until anhydrous DMF is removed, to obtain epoxy-based bamboo fiber, wherein the mass ratio of pretreated bamboo fiber, anhydrous DMF and epichlorohydrin is 5:55:1.2; Step B3: Add epoxy-based bamboo fiber to anhydrous DMF and stir at 600 rpm for 26 min until homogeneous. While stirring, add triethylamine, 4,6-diamino-2-mercaptopyrimidine, and anhydrous DMF mixture b dropwise, controlling the addition to be completed within 10 min at a dropping rate of 5 drops / second. After the addition is complete, heat to 106℃ and stir for 2.8 h. Centrifuge at 7000 rpm for 18 min. Wash five times each with anhydrous ethanol and deionized water (each time the amount of anhydrous ethanol and deionized water is 10% of the mass of anhydrous DMF). Dry at 72℃ to constant weight to obtain mercapto-based bamboo fiber. The mass ratio of epoxy-based bamboo fiber, anhydrous DMF, and mixture b is 0.8:80:35. In mixture b, the mass ratio of triethylamine, 4,6-diamino-2-mercaptopyrimidine, and anhydrous DMF is 0.08:0.5:20.

[0034] Comparative Example 1 Comparative Example 1 is the same as Example 1, except that when preparing functionalized core-shell particles, tetrabutyl titanate is replaced with an equal mass of tetraethyl orthosilicate, while the other steps and raw materials are the same as in Example 1.

[0035] Comparative Example 2 Comparative Example 2 is the same as Example 1, except that when preparing functionalized core-shell particles, α-methylcinnamic acid is replaced with an equal mass of 3-phenylpropionic acid, while the remaining steps and raw materials are the same as in Example 1.

[0036] Comparative Example 3 Comparative Example 3 is the same as Example 1, except that when preparing thiolized bamboo fiber, 4,6-diamino-2-mercaptopyrimidine is replaced with an equal mass of 4,6-diaminopyrimidine, while the other steps and raw materials are the same as in Example 1.

[0037] Comparative Example 4 Comparative Example 4 is the same as Example 1, except that when preparing thiolated bamboo fiber, 4,6-diamino-2-mercaptopyrimidine is replaced with an equal mass of 6-amino-2-mercaptopyrimidine-4-ol, while the other steps and raw materials are the same as in Example 1.

[0038] Performance testing 1. Metal ion content detection: Referring to HG / T 3944-2007 "Determination of metal ion content in polyvinyl chloride resin by ICP method", the metal ion content in the carbon-based stone-plastic composite packaging materials prepared in Examples 1-3 and Comparative Examples 1-4 was determined by inductively coupled plasma atomic emission spectrometry (ICP). The specific test results are shown in Table 2. 2. Mechanical property testing: The tensile strength of the carbon-based stone-plastic composite packaging materials prepared in Examples 1-3 and Comparative Examples 1-4 was determined according to GB / T 8804.2-2003; the impact properties of the carbon-based stone-plastic composite packaging materials prepared in Examples 1-3 and Comparative Examples 1-4 were determined at 20℃ according to GB / T 13525-1992; the elongation at break of the carbon-based stone-plastic composite packaging materials prepared in Examples 1-3 and Comparative Examples 1-4 was determined according to GB / T 5836-1996. Specific test results are shown in Table 2. Table 2 Performance test results of carbon-based stone-plastic composite packaging materials based on industrial solid waste prepared in Examples 1-3 and Comparative Examples 1-4 As can be seen from Table 2, compared with Comparative Examples 1-4, the carbon-based stone-plastic composite packaging material based on industrial solid waste prepared by the method provided in Examples 1-3 has a lower metal residue and higher tensile strength, impact resistance and elongation at break. This indicates that the carbon-based stone-plastic composite packaging material based on industrial solid waste prepared by the present invention not only has better mechanical properties, but also can better adsorb heavy metal ions in the carbon-based stone-plastic composite packaging material, reduce the residual amount of metal ions, and make the prepared carbon-based stone-plastic composite packaging material have a wider range of application prospects.

[0039] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A method for preparing carbon-based stone-plastic composite packaging material based on industrial solid waste, characterized in that, Includes the following steps: Step S1: Prepare the following raw materials by weight: 90-96 parts polyvinyl chloride, 5-10 parts functionalized core-shell particles, 8-10 parts mercaptoized bamboo fiber, 0.8-1.2 parts lubricant, 1.5-3.5 parts heat stabilizer, 0.2-0.4 parts photoinitiator and 10-12 parts organic solvent; Step S2, Mixing and Preparation: Polyvinyl chloride, functionalized core-shell particles, mercaptoized bamboo fiber, lubricant, heat stabilizer and photoinitiator are added to an organic solvent, heated to reflux temperature, stirred evenly, cooled to room temperature, irradiated with ultraviolet light for 14-18 minutes, evaporated under reduced pressure, and then extruded through a twin-screw extruder to obtain carbon-based stone-plastic composite packaging material based on industrial solid waste. The functionalized core-shell particles are first obtained by acid washing of coal gangue to obtain pretreated coal gangue, which is then subjected to alcohol dispersion hydrolysis reaction with tetrabutyl titanate to obtain core-shell particles. After modification with KH-560, epoxy-based core-shell particles are obtained. Finally, they are prepared by ring-opening reaction with α-methylcinnamic acid. The thiolized bamboo fiber is first obtained by treating bamboo fiber with alkali to obtain pretreated bamboo fiber, then reacting it with epichlorohydrin through a nucleophilic substitution reaction to obtain epoxy-based bamboo fiber, and finally reacting it with 4,6-diamino-2-mercaptopyrimidine through a ring-opening reaction to obtain the final product.

2. The method for preparing carbon-based stone-plastic composite packaging material based on industrial solid waste according to claim 1, characterized in that, The functionalized core-shell particles are prepared by the following steps: Step A1: Crush and sieve the coal gangue to a particle size of 150-180μm, then acid wash with hydrochloric acid aqueous solution, filter, wash, dry, crush a second time, and sieve to obtain pretreated coal gangue. Step A2: Add the pretreated coal gangue to an ethanol-water solution, ultrasonically disperse it evenly, add tetrabutyl titanate dropwise while stirring, stir for 1.8-2.2 hours, then add deionized water dropwise, continue stirring for 3.8-4.2 hours, filter, wash, dry, pulverize, and calcine to obtain core-shell particles; Step A3: Ultrasonically mix the core-shell particles, deionized water, anhydrous ethanol, and KH-560 until homogeneous. Heat to 48-56℃ and stir for 5.2-5.8 hours. Centrifuge, wash, and dry to obtain epoxy-based core-shell particles. Ultrasonically disperse the epoxy-based core-shell particles and anhydrous DMF until homogeneous. Dropwise add a mixture of tetrabutylammonium bromide, α-methylcinnamic acid, and anhydrous DMF. After the addition is complete, heat to 92-96℃ and stir for 2.2-2.8 hours. Centrifuge, wash, and dry to obtain functionalized core-shell particles.

3. The method for preparing carbon-based stone-plastic composite packaging material based on industrial solid waste according to claim 2, characterized in that, In step A1, the specific process parameters for pickling are: the mass fraction of hydrochloric acid aqueous solution is 8-12%, the pickling temperature is 40-60℃, and the pickling time is 0.5-0.8h.

4. The method for preparing carbon-based stone-plastic composite packaging material based on industrial solid waste according to claim 2, characterized in that, In step A2, the mass fraction of the ethanol aqueous solution is 16-20%, and the mass ratio of pretreated coal gangue, ethanol aqueous solution, tetrabutyl titanate and deionized water is 2.2-2.8:280-320:6-8:140-160.

5. The method for preparing carbon-based stone-plastic composite packaging material based on industrial solid waste according to claim 2, characterized in that, In step A3, the mass ratio of core-shell particles, deionized water, anhydrous ethanol, and KH-560 is 2.4-2.8:10:30-40:0.5-0.8; the mass ratio of epoxy-based core-shell particles, anhydrous DMF, and mixture a is 3:50-60:20; and in mixture a, the mass ratio of tetrabutylammonium bromide, α-methylcinnamic acid, and anhydrous DMF is 0.1:1-1.2:

20.

6. The method for preparing carbon-based stone-plastic composite packaging material based on industrial solid waste according to claim 1, characterized in that, The thiolized bamboo fiber is prepared by the following steps: Step B1: Wash the bamboo fiber with deionized water, dry it, then immerse it in sodium hydroxide aqueous solution and stir for 3.6-4.4 hours. Take it out, wash it, then place it in acetic acid aqueous solution and adjust the pH to 7. Take it out, wash it, and dry it to obtain pretreated bamboo fiber. Step B2: Add the pretreated bamboo fiber to anhydrous DMF, heat to 45-55℃, stir evenly, add epichlorohydrin dropwise, after the addition is complete, heat to 60-70℃, stir and react for 3-3.4h, and distill under reduced pressure to obtain epoxy-based bamboo fiber. Step B3: Add epoxy-based bamboo fiber to anhydrous DMF and stir until homogeneous. While stirring, add triethylamine, 4,6-diamino-2-mercaptopyrimidine and anhydrous DMF mixture b dropwise. After the addition is complete, heat to 102-106℃ and stir for 2.4-2.8 hours. Centrifuge, wash, and dry to obtain thiolated bamboo fiber.

7. The method for preparing carbon-based stone-plastic composite packaging material based on industrial solid waste according to claim 6, characterized in that, In step B1, the mass ratio of bamboo fiber to sodium hydroxide aqueous solution is 1:40-50; in step B2, the mass ratio of pretreated bamboo fiber, anhydrous DMF and epichlorohydrin is 3-5:45-55:0.7-1.

2.

8. The method for preparing carbon-based stone-plastic composite packaging material based on industrial solid waste according to claim 6, characterized in that, In step B3, the mass ratio of epoxy-based bamboo fiber, anhydrous DMF, and mixture b is 0.4-0.8:60-80:25-35, and the mass ratio of triethylamine, 4,6-diamino-2-mercaptopyrimidine, and anhydrous DMF in mixture b is 0.04-0.08:0.3-0.5:

20.

9. A carbon-based stone-plastic composite packaging material based on industrial solid waste prepared by the method of preparing carbon-based stone-plastic composite packaging material based on industrial solid waste according to any one of claims 1-8.

10. The application of the carbon-based stone-plastic composite packaging material based on industrial solid waste as described in claim 9 in the preparation of outer packaging boxes for fresh food cold chain logistics.

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