High polymer material for adsorbing VOCs organic waste gas

Abstract

The invention discloses a high polymer material for adsorbing VOCs (volatile organic compounds) organic waste gas, belongs to the technical field of high polymer material processing, and aims to solve the technical problem that the VOCs organic waste gas adsorption performance and cyclic adsorption performance of a high polymer material in the prior art need to be further improved. The high-temperature-resistant flame-retardant coating comprises the following raw materials in parts by weight: 30-40 parts of epoxy modified porous bio-based carbon, 50-55 parts of a solvent A, 50-55 parts of a solvent B, 70-80 parts of ammoniated modified polyolefin, 3-5 parts of a template agent and 30-40 parts of phenyl modified silicon resin. According to the preparation method, firstly, the sludge and the wheat straw are carbonized and activated to prepare the porous bio-based carbon, then the ammoniation modified polyolefin is prepared through the free radical polymerization reaction, and finally the high polymer material is prepared through the ring-opening reaction and the hard template method, so that the adsorption performance of the high polymer material is improved, and the cyclic adsorption performance of the high polymer material is effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer material processing, and particularly relates to a polymer material for adsorbing VOCs organic waste gas. Background Art

[0002] As an important type of air pollutant, VOCs are widely present in industrial emissions, automobile exhausts, and daily life. They not only pose a serious threat to ambient air quality but also participate in atmospheric photochemical reactions, leading to ozone layer depletion and the formation of photochemical smog.

[0003] In recent years, with the increasingly strict environmental protection regulations and the enhanced public environmental awareness, the treatment of VOCs has become a research hotspot worldwide. Among them, toluene, as a typical organic waste gas, mainly comes from industries such as chemical engineering, paint, and printing. Its emissions not only pollute the environment but also pose a threat to human health. Given the volatility and toxicity of toluene, its effective treatment has become an important topic in the environmental protection field.

[0004] Currently, the treatment methods for toluene organic waste gas mainly include adsorption method, condensation method, combustion method, and biological method, etc. Among them, the adsorption method is widely used due to its high efficiency, economy, and easy operation. By selecting high-performance adsorption materials such as activated carbon and molecular sieves, toluene molecules can be effectively captured to achieve the purification treatment of waste gas, providing a strong guarantee for environmental protection and human health.

[0005] When applying activated carbon to the adsorption of toluene waste gas, although it has good adsorption capacity, during long-term use, activated carbon is usually brittle, easy to break and not wear-resistant. It may produce debris during the adsorption process or after use, reducing its adsorption performance for toluene waste gas. Especially in a high-concentration waste gas environment, a larger amount of activated carbon may be required to achieve a better removal effect. Combining organic polymers with activated carbon to jointly adsorb toluene waste gas is difficult to achieve a good adsorption effect due to poor interfacial compatibility. Moreover, the preparation of activated carbon requires a large amount of energy consumption and waste gas emissions. Activated carbon has a developed pore structure, and these pores provide adsorption sites for toluene molecules, which can effectively adsorb toluene waste gas. However, during the adsorption process, it can also adsorb water molecules, and these water molecules will compete with toluene molecules for adsorption sites, thereby reducing the adsorption efficiency of activated carbon for toluene. Conventional polymer materials have poor heat resistance and are difficult to adapt to the thermal desorption process of activated carbon, reducing the cyclic adsorption performance. Summary of the Invention

[0006] The purpose of the present invention is to provide a polymer material for adsorbing VOCs organic waste gas, aiming to solve the technical problem that the adsorption efficiency and cyclic adsorption performance of polymer materials for VOCs organic waste gas in the prior art need to be further improved.

[0007] The object of the present invention can be achieved by the following technical solutions: A polymer material for adsorbing VOCs organic waste gas, comprising the following raw materials by weight: 30-40 parts of epoxy-modified porous bio-based carbon, 50-55 parts of solvent A, 50-55 parts of solvent B, 70-80 parts of ammoniated polyolefin, 3-5 parts of template agent, and 30-40 parts of phenyl-modified silicone resin;

[0008] The polymer material is prepared by the following steps:

[0009] A1. Place the ammoniated polyolefin, epoxy-modified porous bio-based carbon, and solvent A in a reaction kettle under nitrogen protection, heat up to 60-70 °C, keep the temperature for reaction for 1-2 h, and perform post-treatment to obtain a composite polyolefin;

[0010] The reaction principle for the preparation of the composite polyolefin is:

[0011] During the reaction process, under the weak alkaline action of ammonia water, the amino group of the ammoniated polyolefin and the epoxy group on the surface of the epoxy-modified porous bio-based carbon undergo a ring-opening reaction to form a chemical bond, resulting in a composite polyolefin.

[0012] A2. Add the composite polyolefin, template agent, and phenyl-modified silicone resin into a twin-screw extruder, melt and extrude, and pelletize to obtain a polymer material precursor;

[0013] A3. Place the polymer material precursor and solvent B in a reaction kettle, heat up to 45-55 °C, stir for 1-2 h, and perform post-treatment to obtain the polymer material.

[0014] The reaction principle for the preparation of the polymer material is:

[0015] During the reaction process, the low-concentration acetic acid solution reacts with the calcium carbonate particles in the polymer material precursor through stirring to generate calcium acetate, carbon dioxide, and water. In the post-treatment step, the calcium acetate is dissolved and removed by deionized water, and under the action of a drying oven, the water generated by the reaction evaporates to obtain a polymer material with a pore structure.

[0016] Further, in step A1, the solvent A is composed of N,N-dimethylformamide and ammonia water in a volume ratio of 50:10, the concentration of the ammonia water is 5-10 wt%, and the post-treatment steps include: after the reaction is completed, perform suction filtration, wash the filter cake with deionized water and ethanol 1-2 times, transfer the filter cake to a drying oven at a temperature of 60-70 °C, and dry to constant weight to obtain a composite polyolefin; in step A2, the template agent is calcium carbonate particles, and the temperatures of the 8 temperature zones of the twin-screw extruder from the feeding end to the discharging end are 200 °C, 210 °C, 210 °C, 215 °C, 215 °C, 215 °C, 215 °C, and 220 °C in sequence, and the main shaft speed of the twin-screw extruder is 15 r / min;

[0017] Furthermore, in step A3, the solvent B consists of an acetic acid solution with a concentration of 10 wt%, and the post-treatment steps include: after the reaction is completed, when the reaction drops to room temperature, perform suction filtration, wash the filter cake with deionized water 1-2 times, transfer it to a drying oven at a temperature of 60-70 °C, and dry it to room temperature to obtain the polymer material.

[0018] Furthermore, the preparation method of the aminated modified polyolefin is as follows: place 4-penten-1-amine, trimethylolpropane triacrylate, divinylbenzene, sodium dodecylbenzenesulfonate, and toluene in a reaction kettle, stir for 10-15 min, add benzoyl peroxide, heat up to 45-55 °C, add deionized water, stir at high speed for 0.5-1 h, add N,N-dimethyl-p-toluidine, keep the temperature for reaction for 1-3 min, and perform post-treatment to obtain the aminated modified polyolefin.

[0019] The reaction principle for the preparation of the aminated modified polyolefin is as follows:

[0020] During the reaction, the olefin double bonds of 4-penten-1-amine, trimethylolpropane triacrylate, and divinylbenzene undergo free radical polymerization under the initiation of benzoyl peroxide. Add N,N-dimethyl-p-toluidine as a reducing agent to form a redox system with benzoyl peroxide, promote the generation of free radicals of benzoyl peroxide, and obtain the aminated modified polyolefin.

[0021] Furthermore, the dosage ratio of 4-penten-1-amine, trimethylolpropane triacrylate, divinylbenzene, sodium dodecylbenzenesulfonate, toluene, benzoyl peroxide, deionized water, and N,N-dimethyl-p-toluidine is 2-4 g: 0.5-1 g: 2-2.5 g: 0.10-0.15 g: 5-10 mL: 0.2-0.5 g: 25-30 mL: 0.5-0.7 mL. The post-treatment steps include: after the reaction is completed, heat the reaction system to 120-130 °C, perform vacuum distillation until no liquid is collected, and obtain the aminated modified polyolefin.

[0022] Furthermore, the epoxy-modified porous biochar is prepared by the following steps:

[0023] B1. Place the bio-based substrate in a drying oven at a temperature of 100-110 °C, dry for 1-2 h, crush it, and pass it through a 100-mesh sieve to obtain a porous biochar precursor;

[0024] B2. Place the porous biochar precursor in a tubular furnace protected by a nitrogen atmosphere, heat up to 550-600 °C, keep the temperature for reaction for 1-2 h, heat up to 750-800 °C, introduce water vapor, and keep the temperature for reaction for 1-2 h to obtain the porous biochar;

[0025] The reaction principle for the preparation of the porous activated carbon is as follows:

[0026] During the reaction process, humus and minerals in the sludge form a microporous framework during pyrolysis, while the wheat straw cellulose forms a mesoporous structure after carbonization. Moreover, high temperature promotes the deoxygenation and condensation of wheat cellulose to form a highly aromatic graphite microcrystalline structure. Adding steam activation can reduce the fouling on the surface of the epoxy-modified porous biochar, and at the same time, the pyrolysis reaction reduces its internal oxygen-containing functional groups, resulting in porous biochar.

[0027] B3. Place the porous biochar, ethanol, and deionized water in a reaction kettle, heat up to 40 - 50 °C, add KH-560, keep the temperature for reaction for 0.5 - 1 h, and perform post-treatment to obtain epoxy-modified porous biochar.

[0028] The preparation reaction principle of the epoxy-modified porous biochar is as follows:

[0029] During the reaction process, the siloxane bonds in KH-560 are hydrolyzed into silanols under the action of deionized water, and the silanols further undergo a condensation reaction with the hydroxyl groups on the surface of the porous biochar to obtain epoxy-modified porous biochar modified with a silane coupling agent.

[0030] Furthermore, in step B1, the biological base material is composed of sludge and wheat straw in a weight ratio of 6:4; in step B2, the heating rate is 10 °C / min; in step B3, the dosage ratio of the porous biochar, ethanol, deionized water, and KH-560 is 6 - 10 g:80 - 100 mL:5 - 10 mL:1 - 1.5 g. The post-treatment steps include: after the reaction ends, wait for the reaction solution to cool to room temperature, filter, wash the filter cake with deionized water and ethanol for 1 - 2 times, transfer it to a drying oven at a temperature of 60 - 80 °C, and dry to constant weight to obtain epoxy-modified porous biochar.

[0031] Furthermore, the preparation method of the phenyl-modified silicone resin is as follows: Place ethanol, deionized water, and tetramethylammonium hydroxide in a reaction kettle, heat up to 30 - 40 °C, stir for 10 - 15 min, add tetraethyl orthosilicate, hexamethyldisiloxane, and methyldiphenyl ethoxysilane, keep the temperature for reaction for 1.5 - 2 h, heat up to 60 - 70 °C, keep the temperature for reaction for 5 - 6 h, and perform post-treatment to obtain phenyl-modified silicone resin.

[0032] The preparation reaction formula of the phenyl-modified silicone resin is:

[0033]

[0034] In the formula:

[0035] The preparation reaction principle of the phenyl-modified silicone resin is:

[0036] During the reaction process, tetramethylammonium hydroxide increases the alkaline environment, promotes the hydrolysis of the silicon-oxygen bonds of tetraethyl orthosilicate, hexamethyldisiloxane and methyldiphenylethoxysilane to form silanols, and the silanols further undergo a condensation reaction to form a three-dimensional network structure, obtaining a phenyl-modified silicone resin capped with methyl and phenyl groups.

[0037] Furthermore, the dosage ratio of ethanol, deionized water, tetramethylammonium hydroxide, tetraethyl orthosilicate, hexamethyldisiloxane and methyldiphenylethoxysilane is 20 - 40 mL: 10 - 15 mL: 0.10 - 0.15 g: 3 - 4 g: 0.5 - 1 g: 1 - 1.5 g. The post-treatment step includes: after the reaction is completed, the reaction system is heated to 100 - 110 °C, and vacuum distillation is carried out until no liquid is collected, obtaining the phenyl-modified silicone resin.

[0038] The present invention has the following beneficial effects:

[0039] 1. A polymer material for adsorbing VOCs organic waste gas prepared by the present invention first uses sludge and wheat straw to be carbonized and activated to prepare porous bio-based carbon, then the porous bio-based carbon is modified with a silane coupling agent to obtain epoxy-modified porous bio-based carbon with epoxy groups attached to the surface, and then through a free radical polymerization reaction, using acrylate substances as raw materials, a polyolefin with amino modification is prepared. Finally, through a ring-opening reaction, the epoxy-modified porous bio-based carbon and the amino-modified polyolefin form a chemical bond, obtaining a composite polyolefin. The composite polyolefin is melt-extruded and pelletized with a template agent and a phenyl-modified silicone resin, and then the calcium carbonate particles are removed by acetic acid solution and deionized water to prepare the polymer material; the amino-modified polyolefin prepared by the present invention uses 4-penten-1-amine, trimethylolpropane triacrylate, and divinylbenzene as polymerization monomers, and under the initiation of benzoyl peroxide, forms an amino-modified polyolefin. N,N-dimethyl-p-toluidine is added as a reducing agent to form a redox system with benzoyl peroxide, promoting the generation of free radicals of benzoyl peroxide, obtaining an amino-modified polyolefin. The polyolefin molecular chain has high chemical stability, can reduce the swelling phenomenon generated by the polymer material adsorbing toluene gas, and further improves the cyclic adsorption performance of the polymer material.

[0040] 2. The present invention uses sludge and wheat straw as raw materials, and through high-temperature carbonization and steam activation, an epoxy-modified porous bio-based carbon is prepared. Humus and minerals in the sludge form a microporous framework during pyrolysis, while the wheat straw cellulose forms a mesoporous structure after carbonization. Moreover, high temperature promotes the deoxygenation and condensation of wheat cellulose to form a highly aromatic graphite microcrystalline structure. Its π electron cloud undergoes π-π conjugation with the benzene ring of toluene, significantly enhancing the adsorption force of toluene gas. Its micropores directly capture toluene gas molecules through van der Waals forces, enhancing the physical adsorption efficiency. The mesopores serve as mass transfer channels, reducing the diffusion resistance of toluene and enhancing the dynamic adsorption rate. The steam reacts with the carbon framework, etching and closing the pore channels and expanding the pore volume, increasing its specific surface area. After activation, the microporosity increases, further strengthening the van der Waals interaction between toluene molecules and the pore wall, improving the adsorption capacity and adsorption rate of the polymer material for toluene. Moreover, steam activation can reduce the dirt on the surface of the epoxy-modified porous bio-based carbon. At the same time, the pyrolysis reaction reduces its internal oxygen-containing functional groups, decreasing the hydrophilicity and forming a hydrophobic surface, avoiding the competitive adsorption of water molecules and toluene, and enabling the polymer material to maintain a high adsorption capacity in a humid environment. Using biological materials to prepare bioactive carbon can also improve the environmental performance of the polymer material.

[0041] 3. The present invention also combines the epoxy-modified porous bio-based carbon with the aminated polyolefin through a ring-opening reaction to obtain a composite polyolefin, which reduces the interfacial tension between the epoxy-modified porous bio-based carbon and the aminated polyolefin, improves the dispersibility of the epoxy-modified porous bio-based carbon in the polymer material, and further improves the adsorption performance of the polymer material for toluene gas. Then, through a template agent, the composite polyolefin and the phenyl-modified silicone resin are prepared into a polymer material with a hierarchical pore structure, improving the specific surface area and adsorption performance of the polymer material. The phenyl-modified silicone resin is formed by the hydrolysis of the silicon-oxygen bond of tetraethyl orthosilicate, hexamethyldisiloxane, and methyldiphenylethoxysilane to form silanols, and the silanols further undergo a condensation reaction to form a three-dimensional network structure, obtaining a phenyl-modified silicone resin capped with methyl and phenyl groups. The silicon-oxygen chain structure is stable, having good thermal stability and chemical inertness, and the methyl and phenyl groups are hydrophobic, improving the stability and hydrophobicity of the polymer material, which is beneficial to maintaining the structural stability of the polymer material during thermal desorption and improving its cyclic adsorption performance. Detailed implementation mode

[0042] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0043] The calcium carbonate particles used in the present invention are purchased from Shijiazhuang Weijia Mineral Products Co., Ltd., with particle sizes of 10 - 120 mesh, 200 mesh, and 325 mesh.

[0044] Example 1

[0045] This example provides a method for preparing a polymer material for adsorbing VOCs organic waste gas, including the following steps:

[0046] S1. Preparation of aminated modified polyolefin

[0047] Weigh: 200 g of 4-penten-1-amine, 50 g of trimethylolpropane triacrylate, 200 g of divinylbenzene, 10 g of sodium dodecylbenzenesulfonate, and 500 mL of toluene and place them in a reaction kettle. Stir for 10 min, add 20 g of benzoyl peroxide, heat up to 45 °C, add 2500 mL of deionized water, stir at a rate of 8000 r / min for 0.5 h, add 50 mL of N,N-dimethyl-p-toluidine, keep the temperature for reaction for 1 min. After the reaction is completed, raise the temperature of the reaction system to 120 °C and distill under reduced pressure until no liquid is collected to obtain the aminated modified polyolefin.

[0048] S2. Preparation of epoxy modified porous biochar

[0049] Place the biological substrate in an oven at 100 °C and dry for 1 h, then crush it and sieve it through a 100-mesh sieve to obtain a porous biochar precursor;

[0050] Place the porous biochar precursor in a tube furnace protected by a nitrogen atmosphere, heat it up to 550 °C at a rate of 10 °C / min, keep the temperature for reaction for 1 - 2 h, then heat it up to 750 °C at a rate of 10 °C / min, introduce water vapor, and keep the temperature for reaction for 1 h to obtain the porous biochar;

[0051] Weigh: 600 g of porous biochar, 8000 mL of ethanol, and 500 mL of deionized water and place them in a reaction kettle. Heat up to 40 °C, add 100 g of KH-560, keep the temperature for reaction for 0.5 h. After the reaction is completed, wait for the reaction solution to cool to room temperature, filter it, wash the filter cake with deionized water and ethanol once, transfer it to an oven at 60 °C, and dry it to constant weight to obtain the epoxy modified porous biochar.

[0052] S3. Preparation of phenyl modified silicone resin

[0053] Weigh: 2000 mL of ethanol, 1000 mL of deionized water, and 10 g of tetramethylammonium hydroxide and place them in a reaction kettle. Heat up to 30 °C and stir for 10 min. Then add 300 g of tetraethyl orthosilicate, 50 g of hexamethyldisiloxane, and 100 g of methyldiphenylethoxysilane. Keep the temperature for reaction for 1.5 h, then heat up to 60 °C and keep the temperature for reaction for 5 h. After the reaction is completed, heat up the reaction system to 100 °C and perform vacuum distillation until no liquid is collected, obtaining phenyl-modified silicone resin.

[0054] S4. Preparation of polymer material

[0055] Mix N,N-dimethylformamide and 5 wt% ammonia water evenly at a volume ratio of 50:10 to obtain solvent A;

[0056] Weigh by mass parts: 30 parts of epoxy-modified porous bio-based carbon, 50 parts of solvent A, 50 parts of 10 wt% acetic acid solution, 70 parts of ammoniated polyolefin, 3 parts of calcium carbonate particles, and 30 parts of phenyl-modified silicone resin for standby;

[0057] Place the ammoniated polyolefin and solvent A in a reaction kettle under nitrogen protection, add epoxy-modified porous bio-based carbon, heat up to 60 °C, and keep the temperature for reaction for 1 h. After the reaction is completed, perform suction filtration, wash the filter cake once with deionized water and ethanol, transfer the filter cake to a drying oven at 60 °C, and dry to constant weight to obtain composite polyolefin;

[0058] Add the composite polyolefin, calcium carbonate particles, and phenyl-modified silicone resin into a twin-screw extruder. The temperatures of the 8 temperature zones of the twin-screw extruder from the feeding end to the discharging end are 200 °C, 210 °C, 210 °C, 215 °C, 215 °C, 215 °C, 215 °C, and 220 °C in sequence. The main shaft speed of the twin-screw extruder is 15 r / min. Perform melt extrusion and pelletization to obtain a polymer material precursor;

[0059] Place the polymer material precursor and 10 wt% acetic acid solution in a reaction kettle, heat up to 45 °C, and stir for 1 h. After the reaction is completed, wait for the reaction to cool to room temperature, perform suction filtration, wash the filter cake once with deionized water, transfer it to a drying oven at 60 °C, and dry to room temperature to obtain the polymer material.

[0060] Example 2

[0061] This example provides a preparation method of a polymer material for adsorbing VOCs organic waste gas, including the following steps:

[0062] S1. Preparation of ammoniated polyolefin

[0063] Weigh: 300 g of 4-penten-1-amine, 70 g of trimethylolpropane triacrylate, 220 g of divinylbenzene, 12 g of sodium dodecylbenzenesulfonate and 700 mL of toluene and place them in a reaction kettle. Stir for 13 min, add 35 g of benzoyl peroxide, heat up to 50 °C, add 2700 mL of deionized water, stir at a rate of 8000 r / min for 0.5 h, add 60 mL of N,N-dimethyl-p-toluidine, keep the temperature for reaction for 2 min. After the reaction is completed, heat up the reaction system to 125 °C and carry out vacuum distillation until no liquid is drawn out to obtain the aminated modified polyolefin.

[0064] S2. Prepare epoxy-modified porous biochar

[0065] Place the biological base material in a drying oven at 105 °C, dry for 1.5 h, crush it, and pass through a 100-mesh sieve to obtain a porous biochar precursor.

[0066] Place the porous biochar precursor in a tubular furnace protected by a nitrogen atmosphere, heat it up to 570 °C at a rate of 10 °C / min, keep the temperature for reaction for 1.5 h, heat it up to 770 °C at a rate of 10 °C / min, introduce water vapor, and keep the temperature for reaction for 1.5 h to obtain porous biochar.

[0067] Weigh: 800 g of porous biochar, 9000 mL of ethanol and 700 mL of deionized water and place them in a reaction kettle. Heat up to 45 °C, add 120 g of KH-560, keep the temperature for reaction for 1 h. After the reaction is completed, wait for the reaction solution to cool to room temperature, filter it, wash the filter cake with deionized water and ethanol twice, transfer it to a drying oven at 70 °C, and dry it to constant weight to obtain epoxy-modified porous biochar.

[0068] S3. Prepare phenyl-modified silicone resin

[0069] Weigh: 3000 mL of ethanol, 1250 mL of deionized water and 12 g of tetramethylammonium hydroxide and place them in a reaction kettle. Heat up to 35 °C, stir for 12 min, add 3504 g of tetraethyl orthosilicate, 70 g of hexamethyldisiloxane and 125 g of methyldiphenylethoxysilane, keep the temperature for reaction for 2 h, heat up to 65 °C, keep the temperature for reaction for 5.5 h. After the reaction is completed, heat up the reaction system to 105 °C and carry out vacuum distillation until no liquid is drawn out to obtain phenyl-modified silicone resin.

[0070] S4. Prepare polymer materials

[0071] Mix N,N-dimethylformamide and 5 wt% ammonia water evenly according to a volume ratio of 50:10 to obtain solvent A.

[0072] Weigh by mass parts: 35 parts of epoxy-modified porous bio-based carbon, 52 parts of solvent A, 52 parts of 10 wt% acetic acid solution, 75 parts of aminated polyolefin, 4 parts of calcium carbonate particles, and 35 parts of phenyl-modified silicone resin, and set aside;

[0073] Place the aminated polyolefin and solvent A in a reaction kettle under nitrogen protection, add the epoxy-modified porous bio-based carbon, heat up to 65 °C, hold the temperature for reaction for 1.5 h. After the reaction is completed, perform suction filtration. Wash the filter cake twice with deionized water and ethanol. Transfer the filter cake to a drying oven at 65 °C and dry to constant weight to obtain the composite polyolefin;

[0074] Add the composite polyolefin, calcium carbonate particles, and phenyl-modified silicone resin into a twin-screw extruder. The temperatures of the 8 temperature zones of the twin-screw extruder from the feeding end to the discharging end are 200 °C, 210 °C, 210 °C, 215 °C, 215 °C, 215 °C, 215 °C, and 220 °C in sequence. The main shaft rotation speed of the twin-screw extruder is 15 r / min. Melt and extrude, and pelletize to obtain the polymer material precursor;

[0075] Place the polymer material precursor and 10 wt% acetic acid solution in a reaction kettle, heat up to 50 °C, stir for 1.5 h. After the reaction is completed, wait for the reaction to cool to room temperature, perform suction filtration. Wash the filter cake twice with deionized water, transfer it to a drying oven at 65 °C, and dry to room temperature to obtain the polymer material.

[0076] Example 3

[0077] This example provides a preparation method of a polymer material for adsorbing VOCs organic waste gas, including the following steps:

[0078] S1. Prepare aminated polyolefin

[0079] Weigh: 400 g of 4-penten-1-amine, 100 g of trimethylolpropane triacrylate, 250 g of divinylbenzene, 15 g of sodium dodecylbenzenesulfonate, and 1000 mL of toluene, place them in a reaction kettle, stir for 15 min, add 50 g of benzoyl peroxide, heat up to 55 °C, add 3000 mL of deionized water, stir at a rate of 8000 r / min for 1 h, add 70 mL of N,N-dimethyl-p-toluidine, hold the temperature for reaction for 3 min. After the reaction is completed, heat up the reaction system to 130 °C and perform vacuum distillation until no liquid is collected to obtain the aminated polyolefin.

[0080] S2. Prepare epoxy-modified porous bio-based carbon

[0081] Mix 10 mm zirconia and 6 mm zirconia evenly according to a mass ratio of 1:1 to obtain the ball milling medium, and set aside;

[0082] Place the biological base material in a drying oven at a temperature of 110 °C, dry for 2 h, crush, and pass through a 100-mesh sieve to obtain a porous biochar precursor;

[0083] Place the porous biochar precursor in a tubular furnace protected by a nitrogen atmosphere, heat it to 600 °C at a rate of 10 °C / min, hold for 2 h, heat it to 800 °C at a rate of 10 °C / min, introduce steam, and hold for 2 h to obtain porous biochar;

[0084] Weigh: 1000 g of porous biochar, 10000 mL of ethanol, and 1000 mL of deionized water, place them in a reaction kettle, heat to 50 °C, add 150 g of KH-560, hold for 1 h. After the reaction is completed, wait for the reaction solution to cool to room temperature, filter, wash the filter cake with deionized water and ethanol twice, transfer it to a drying oven at 80 °C, and dry to constant weight to obtain epoxy-modified porous biochar.

[0085] S3. Prepare phenyl-modified silicone resin

[0086] Weigh: 4000 mL of ethanol, 1500 mL of deionized water, and 15 g of tetramethylammonium hydroxide, place them in a reaction kettle, heat to 40 °C, stir for 15 min, add 400 g of tetraethyl orthosilicate, 100 g of hexamethyldisiloxane, and 150 g of methyldiphenylethoxysilane, hold for 2 h, heat to 70 °C, hold for 6 h. After the reaction is completed, heat the reaction system to 110 °C and distill under reduced pressure until no liquid is collected to obtain phenyl-modified silicone resin.

[0087] S4. Prepare polymer materials

[0088] Mix N,N-dimethylformamide and 5 wt% ammonia water evenly according to a volume ratio of 50:10 to obtain solvent A;

[0089] Weigh by mass: 40 parts of epoxy-modified porous biochar, 55 parts of solvent A, 55 parts of 10 wt% acetic acid solution, 80 parts of ammoniated polyolefin, 5 parts of calcium carbonate particles, and 40 parts of phenyl-modified silicone resin for standby;

[0090] Place the ammoniated polyolefin and solvent A in a reaction kettle protected by nitrogen, add epoxy-modified porous biochar, heat to 70 °C, hold for 2 h. After the reaction is completed, filter by suction, wash the filter cake with deionized water and ethanol twice, transfer the filter cake to a drying oven at 70 °C, and dry to constant weight to obtain composite polyolefin;

[0091] Add composite polyolefin, calcium carbonate particles and phenyl-modified silicone resin into a twin-screw extruder. The temperatures of the 8 temperature zones of the twin-screw extruder from the feeding end to the discharging end are 200 °C, 210 °C, 210 °C, 215 °C, 215 °C, 215 °C, 215 °C, 220 °C in sequence. The main shaft rotation speed of the twin-screw extruder is 15 r / min. Melt and extrude, and pelletize to obtain a polymer material precursor;

[0092] Place the polymer material precursor and 10 wt% acetic acid solution in a reaction kettle, heat up to 55 °C, stir for 2 h. After the reaction is completed, wait for the reaction to cool to room temperature, carry out suction filtration, wash the filter cake with deionized water twice, transfer it to a drying oven at 70 °C, and dry to room temperature to obtain a polymer material.

[0093] Comparative Example 1

[0094] The difference between this comparative example and Example 2 is that in step S1, the step of preparing ammoniated modified polyolefin is cancelled. When preparing the polymer material in step S4, epoxy-modified porous biochar is used to replace the composite polyolefin in equal amount.

[0095] Comparative Example 2

[0096] The difference between this comparative example and Example 2 is that in step S2, the step of introducing steam during the preparation of porous biochar is cancelled. In step S2, when preparing epoxy-modified porous biochar, porous biochar precursor is used to replace porous biochar in equal amount.

[0097] Comparative Example 3

[0098] The difference between this comparative example and Example 2 is that step S3 is cancelled, and the step of adding phenyl-modified silicone resin is cancelled in step S4.

[0099] Comparative Example 4

[0100] The difference between this comparative example and Example 2 is that in step S4, the step of adding a template agent is cancelled.

[0101] Performance test:

[0102] Refer to GB / T 19587-2017 "Determination of Specific Surface Area of Solid Materials by Gas Adsorption BET Method" to test the specific surface area of the polymer materials prepared in Examples 1-3 and Comparative Examples 1-4;

[0103] Refer to GB / T 35815-2018 "Test Methods for Wood Activated Carbon - Determination of Toluene Adsorption Rate" to test the toluene adsorption rate of the polymer materials prepared in Examples 1-3 and Comparative Examples 1-4 under the humidity conditions of 0 RT% and 50 RT%;

[0104] The polymer materials prepared in Examples 1-3 and Comparative Examples 1-4 were loaded into a fixed-bed adsorption column. Under the conditions of a temperature of 40 °C and a humidity of 15 RH%, toluene gas with a concentration of 2400 mg / m 3 was introduced into the inlet. Referring to the method for measuring the toluene adsorption rate in GB / T 35815-2018 "Test Methods for Wood Activated Carbon - Determination of Toluene Adsorption Rate", the concentration of toluene gas at the outlet was measured. When the concentration of toluene gas at the outlet reached 5% of the toluene gas concentration at the inlet, it was recorded as the toluene breakthrough time;

[0105] The adsorption specific volume of the polymer materials prepared in Examples 1-3 and Comparative Examples 1-4 was tested with reference to GB / T 21650.2-2008 "Determination of Pore Size Distribution and Porosity of Solid Materials by Mercury Intrusion and Gas Adsorption - Part 2: Gas Adsorption Method for Analysis of Mesopores and Macropores". The adsorbed polymer materials were placed in an oven at a temperature of 150 °C for thermal desorption for 1 h. After thermal desorption, the polymer materials were subjected to cyclic adsorption, and the specific adsorption volume after 5 cycles of adsorption was tested. The specific data are shown in Table 1.

[0106] Table 1. Performance test data of samples

[0107]

[0108] Data analysis:

[0109] By comparing and analyzing the data in Table 1, the specific surface area of a polymer material for adsorbing VOCs organic waste gas prepared by the present invention reached 135.14 m 2 ·g, and the toluene adsorption rates under the conditions of 0 RH% and 50 RH% were 220.89 mg·g -1 and 210.46 mg·g -1 , respectively. The toluene adsorption breakthrough time reached 55 min, the specific adsorption volume of toluene gas for the first time was 2.51 cm·g -1 and the specific adsorption volume of toluene gas after 5 cycles was 2.16 cm·g -1 ;

[0110] By analyzing and comparing the data of Comparative Example 1 and Example 2, it was found that the specific toluene gas adsorption volume after 5 cycles of Comparative Example 1 decreased significantly, indicating that the aminated modified polyolefin prepared by the present invention, using 4-penten-1-amine, trimethylolpropane triacrylate, and divinylbenzene as polymerization monomers, formed an aminated modified polyolefin under the initiation of benzoyl peroxide. N,N-dimethyl-p-toluidine was added as a reducing agent to form a redox system with benzoyl peroxide, promoting the generation of free radicals of benzoyl peroxide, and obtaining an aminated modified polyolefin. The molecular chain of the polyolefin has high chemical stability, which can reduce the swelling phenomenon caused by the adsorption of toluene gas by the polymer material, and further improve the cyclic adsorption performance of the polymer material.

[0111] By analyzing and comparing the data of Comparative Example 2 and Example 2, it was found that the specific surface area, toluene adsorption rate, toluene adsorption breakthrough time, and initial specific toluene gas adsorption volume of Comparative Example 2 under 0RH% and 50RH% conditions decreased significantly, indicating that the present invention uses sludge and wheat straw as raw materials, and prepares epoxy-modified porous biochar through high-temperature carbonization and steam activation. Humus and minerals in the sludge form a microporous framework during pyrolysis, while the wheat straw cellulose forms a mesoporous structure after carbonization, and high temperature promotes the deoxygenation and condensation of wheat cellulose to form a highly aromatic graphite microcrystalline structure. Its π electron cloud undergoes π-π conjugation with the benzene ring of toluene, significantly enhancing the adsorption affinity for toluene gas. Its micropores directly capture toluene gas molecules through van der Waals forces, enhancing the physical adsorption efficiency. The mesopores serve as mass transfer channels, reducing the diffusion resistance of toluene and enhancing the dynamic adsorption rate. Steam reacts with the carbon skeleton, etching and closing the pores and expanding the pore volume, increasing its specific surface area. After activation, the microporosity increases, further strengthening the van der Waals interaction between toluene molecules and the pore wall, increasing the adsorption amount and adsorption rate of the polymer material for toluene. At the same time, steam activation can reduce the dirt on the surface of the epoxy-modified porous biochar, and the pyrolysis reaction reduces its oxygen-containing functional groups, reducing hydrophilicity and forming a hydrophobic surface, avoiding competitive adsorption between water molecules and toluene, and enabling the polymer material to maintain a high adsorption capacity in a humid environment;

[0112] By analyzing and comparing the data of Comparative Example 3 and Example 2, it is found that the toluene adsorption rate, toluene adsorption breakthrough time, first toluene gas specific adsorption volume, and toluene gas specific adsorption volume after 5 cycles under the conditions of 0RH% and 50RH% in Comparative Example 3 decreased significantly. This shows that in the present invention, epoxy-modified porous bio-based carbon is combined with ammoniated polyolefin through ring-opening reaction to obtain a composite polyolefin, which reduces the interfacial tension between epoxy-modified porous bio-based carbon and ammoniated polyolefin, improves the dispersion of epoxy-modified porous bio-based carbon in the polymer material, and further improves the adsorption performance of the polymer material for toluene gas. Then, a polymer material with a hierarchical pore structure is prepared from the composite polyolefin and phenyl-modified silicone resin through a template agent. The phenyl-modified silicone resin is formed by hydrolysis of the silicon-oxygen bond of tetraethyl orthosilicate, hexamethyldisiloxane, and methyldiphenylethoxysilane to form silanol, and the silanol further undergoes a condensation reaction to form a three-dimensional network structure, obtaining phenyl-modified silicone resin capped with methyl and phenyl groups. The silicon-oxygen chain structure is stable, with good thermal stability and chemical inertness, and the methyl and phenyl groups are hydrophobic, which improves the stability and hydrophobicity of the polymer material, is beneficial to maintaining the structural stability of the polymer material during thermal desorption, and improves its cyclic adsorption performance;

[0113] By analyzing and comparing the data of Comparative Example 4 and Example 2, it is found that the specific surface area, toluene adsorption rate, toluene adsorption breakthrough time, and first toluene gas specific adsorption volume under the conditions of 0RH% and 50RH% in Comparative Example 4 decreased significantly. This shows that in the present invention, a polymer material with a hierarchical pore structure is prepared from the composite polyolefin and phenyl-modified silicone resin through a template agent, which improves the specific surface area and adsorption performance of the polymer material.

[0114] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor limit the invention to the specific embodiments described. Obviously, many modifications and variations can be made according to the content of this specification. These embodiments are selected and specifically described in this specification to better explain the principle and practical application of the present invention, so that those skilled in the art can understand and utilize the present invention well. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A polymer material for absorbing VOCs organic waste gas, characterized in that: The method comprises the following raw materials in parts by weight: 30-40 parts of epoxy-modified porous bio-based carbon, 50-55 parts of solvent A, 50-55 parts of solvent B, 70-80 parts of aminated modified polyolefin, 3-5 parts of template agent and 30-40 parts of phenyl modified silicone resin; The polymer material is prepared by the following steps: A1, placing the ammonium-modified polyolefin, epoxy-modified porous bio-based carbon and solvent A in a nitrogen-protected reactor, heating to 60-70°C, keeping the temperature for 1-2h, and post-treating to obtain a composite polyolefin; A2, adding the composite polyolefin, the template agent and the phenyl-modified silicone resin into a twin-screw extruder, melt-extruding, and pelletizing to obtain a polymer material precursor; A3. Place the polymer material precursor and solvent B in a reaction kettle, heat to 45-55°C, stir for 1-2h, and post-treat to obtain the polymer material.

2. The polymer material for adsorbing VOCs organic waste gas according to claim 1, characterized in that: In step A1, the solvent A is composed of N,N-dimethylformamide and ammonia water in a volume ratio of 50:10, and the concentration of the ammonia water is 5-10wt%; in step A2, the template agent is calcium carbonate particles; in step A3, the solvent B is composed of an acetic acid solution with a concentration of 10wt%.

3. The polymer material for adsorbing VOCs organic waste gas according to claim 1, characterized in that: The preparation method of the ammonium-modified polyolefin is as follows: 4-pentene-1-amine, trimethylolpropane triacrylate, divinylbenzene, sodium dodecylbenzene sulfonate and toluene are placed in a reaction kettle, stirred for 10-15 minutes, benzoyl peroxide is added, the temperature is raised to 45-55° C., deionized water is added, high-speed stirring is performed for 0.5-1 hour, the temperature is kept for reaction for 1-3 minutes, and post-treatment is performed to obtain the ammonium-modified polyolefin.

4. The polymer material for adsorbing VOCs organic waste gas according to claim 3, characterized in that: The dosage ratio of the 4-penten-1-amine, trimethylolpropane triacrylate, divinylbenzene, sodium dodecylbenzene sulfonate, toluene, benzoyl peroxide, deionized water and N,N-dimethyl-p-toluidine is 2-4g:0.5-1g:2-2.5g:0.10-0.15g:5-10mL:0.2-0.5g:25-30mL:0.5-0.7mL.

5. The polymer material for adsorbing VOCs organic waste gas according to claim 1, characterized in that: The epoxy-modified porous bio-based carbon is prepared by the following steps: B1. Place the bio-based material in a drying oven at a temperature of 100-110°C, dry for 1-2 hours, crush, and pass through a 100-mesh sieve to obtain a porous bio-based carbon precursor; B2. Place the porous bio-based carbon precursor in a tubular furnace protected by a nitrogen atmosphere, heat it to 550-600°C, keep it warm for 1-2 hours, heat it to 750-800°C, introduce water vapor, keep it warm for 1-2 hours, and obtain porous bio-based carbon; B3. Place porous bio-based carbon, ethanol and deionized water in a reactor, heat to 40-50°C, add KH-560, keep warm for 0.5-1h, and post-treat to obtain epoxy-modified porous bio-based carbon.

6. The polymer material for adsorbing VOCs organic waste gas according to claim 5, characterized in that: In step B1, the bio-based material is composed of sludge and wheat straw in a weight ratio of 6:4; in step B2, the heating rate is 10°C / min; in step B3, the usage ratio of the porous bio-based carbon, ethanol, deionized water and KH-560 is 6-10g:80-100mL:5-10mL:1-1.5g.

7. The polymer material for adsorbing VOCs organic waste gas according to claim 1, characterized in that: The preparation method of the phenyl modified silicone resin is as follows: ethanol, deionized water and tetramethylammonium hydroxide are placed in a reaction kettle, the temperature is raised to 30-40° C., stirring for 10-15 minutes, ethyl orthosilicate, hexamethyldisiloxane and methyldiphenylethoxysilane are added, the temperature is kept for reaction for 1.5-2 hours, the temperature is raised to 60-70° C., the temperature is kept for reaction for 5-6 hours, and the phenyl modified silicone resin is obtained.

8. The polymer material for adsorbing VOCs organic waste gas according to claim 7, characterized in that: The dosage ratio of the ethanol, deionized water, tetramethylammonium hydroxide, ethyl orthosilicate, hexamethyldisiloxane and methyldiphenylethoxysilane is 20-40 mL: 10-15 mL: 0.10-0.15 g: 3-4 g: 0.5-1 g: 1-1.5 g.

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