PU (polyurethane) regenerated cotton composite material for automobile and green preparation process of PU regenerated cotton composite material

Abstract

The invention belongs to the field of PU regenerated cotton composite materials, and particularly relates to a PU regenerated cotton composite material for an automobile and a green preparation process of the PU regenerated cotton composite material. The cleaning solution is synthesized and used for recycling and cleaning the waste PU sponge, the impurity scavenging agent with temperature responsiveness and pH responsiveness is synthesized, the cleaning agent can efficiently remove pollutants such as grease, chemical pollutants and glue by adjusting the temperature and the pH value, meanwhile, damage to the PU sponge is avoided, and the cleaning agent is environmentally friendly. And cyclic utilization can be achieved in the cleaning process. The scheme has relatively strong innovativeness and environmental protection property, meets the requirements of the modern manufacturing industry on sustainable development and resource recycling, and has relatively high potential.

Description

Technical Field

[0001] The invention belongs to the field of PU recycled cotton composite materials, in particular to a PU recycled cotton composite material for automobiles and a green preparation process thereof. Background Art

[0002] With the increasing requirements for environmental protection and the urgent need for sustainable resource utilization, the research on recycling and reuse of waste has become one of the important directions of modern industrial development. Among them, the recycling of polyurethane (PU) materials is a crucial topic, especially in the field of automobile manufacturing. Polyurethane materials are widely used in automobile interiors, seats, sound insulation materials and other components due to their excellent properties, such as light weight, wear resistance, and good elasticity. However, with the scrapping and repair of vehicles, the amount of polyurethane materials discarded has increased year by year, causing resource waste and environmental pollution. In response to this problem, how to efficiently and environmentally friendly recycle and reuse waste PU materials has become a hot topic in current research.

[0003] At present, the technologies for recycling PU sponges mainly include physical recycling, chemical recycling and thermal recycling. Physical recycling usually processes PU sponges into particles or small pieces by crushing and pulverizing, and then reprocesses them into new materials by hot pressing, foaming and other means. However, this method can often only recover part of the relatively complete PU sponge, and the performance of the recycled material is poor and cannot meet the standards of new PU sponges. Chemical recycling decomposes the polyurethane in the waste PU sponge through chemical reactions, recovers basic unit materials such as polyethers and polyols, and then synthesizes new materials. Although this method can effectively recover the main components of polyurethane, it has certain limitations because it involves high temperature and high pressure conditions, and the by-products in the chemical recycling process will cause a certain burden on the environment.

[0004] Among these recycling methods, how to effectively clean and remove pollutants from PU sponges is one of the key factors affecting the recycling effect. Since PU sponges will absorb a large amount of stains, grease, chemical pollutants, etc. during long-term use, these pollutants must be effectively removed during the recycling process to ensure the performance and quality of the recycled materials. Traditional cleaning agents are mostly chemical solvents or strong acid and alkali solutions. While removing dirt, these cleaning agents may damage the PU sponge, affecting its mechanical properties and service life, and also causing serious pollution.

[0005] Therefore, developing a cleaning agent that can efficiently clean PU sponge and can be recycled has become one of the difficulties in current recycling technology. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention provides a PU recycled cotton composite material for automobiles and an green preparation process thereof.

[0007] A preparation process of a PU recycled cotton composite material for automobiles, comprising the following steps:

[0008] (1) Crushing: Crushing the waste automobile interior PU sponge material obtained from an automobile dismantling plant, an automobile repair plant or an abandoned vehicle recycling system into particles of 1-2 mm to obtain PU sponge particles;

[0009] (2) Cleaning: Cleaning the PU sponge particles obtained in step (1) with a cleaning solution, and then dehydrating and drying to obtain clean PU sponge particles;

[0010] (3) Foaming and curing: the clean PU sponge particles obtained in step (2), liquid polyurethane, isocyanate, water, dibutyltin chloride, and dioctyl phthalate are mixed in a mass ratio of 500: (250-500): (250-500): (10-15): (1-3): (20-30), stirred and foamed at 100-120° C. and 0.1-0.3 Mpa for 15-30 min, heated to 160-170° C. and cured for 15-60 min to obtain the PU recycled cotton composite material for automobiles.

[0011] The formula of the cleaning solution is composed of the following raw materials:

[0012] Orange peel essential oil: 10-15wt%

[0013] Citric acid: 5-8wt%

[0014] Surfactant: 5-9wt%

[0015] Glycerol: 2-3wt%

[0016] Propylene glycol: 1-2wt%

[0017] Impurity cleaning agent: 6-8wt%

[0018] The balance is water.

[0019] The surfactant is at least one of polyethylene glycol caprylate, octylphenoxyethanol, sorbitan monooleate, and cocamidopropyl betaine.

[0020] The preparation method of the impurity cleaning agent comprises the following steps:

[0021] S1: adding 9-11 g of N-isopropylacrylamide, 3.5-4.5 g of acrylic acid and 1-3 g of vinylimidazole to 180-220 mL of water, stirring until the monomers are completely dissolved to obtain a reaction precursor solution;

[0022] S2: dissolving 0.4-0.6 g of ammonium persulfate in 4-6 mL of water to obtain an ammonium persulfate aqueous solution;

[0023] S3: placing the reaction precursor solution obtained in step S1 at 55-70° C. and stirring under a nitrogen atmosphere, and adding the ammonium persulfate aqueous solution obtained in step S2 dropwise thereto at a rate of 0.5-1.5 mL / min. After the addition is completed, reacting at a constant temperature of 55-70° C. for 3-5 hours, cooling to room temperature in a 0-4° C. water bath, and then heating to 40-45° C., filtering to obtain a filter cake, and drying to obtain the impurity cleaning agent.

[0024] The present invention aims at the problem that PU sponge will absorb a large amount of stains, grease, chemical pollutants, etc. during long-term use. These pollutants must be effectively removed during the recycling process to ensure the performance and quality of the recycled materials. Traditional cleaning agents are mostly chemical solvents or strong acid and alkali solutions. These cleaning agents may damage the PU sponge while removing dirt, affecting its mechanical properties and service life, and causing serious pollution. A cleaning liquid is configured, which has the ability of efficient decontamination and can be recycled, which reduces processing costs and solvent pollution.

[0025] In order to improve the cleaning efficiency of the cleaning liquid, the present invention adds orange peel essential oil, citric acid, a surfactant, glycerin and propylene glycol into the formula of the cleaning liquid.

[0026] Orange peel essential oil has the natural ability to dissolve oil and organic pollutants. Its components (such as limonene) can effectively dissolve oil and glue in PU sponge at a certain concentration without damaging the structure of PU sponge.

[0027] Citric acid As a mild organic acid, citric acid can effectively remove mineral pollution (such as calcium and magnesium salt deposits) and minor dirt. Due to its acidic properties, it can help dissolve some metal salts or other water-soluble pollutants through weak acid reactions.

[0028] Cocamidopropyl betaine is a good surfactant that can reduce the surface tension of water, thereby improving the wettability and penetration of the cleaning fluid, and helping to remove stubborn contaminants such as grease, dyes and glue on the surface of PU sponge.

[0029] Glycerin can increase the viscosity of aqueous solutions, which helps improve the detergent's ability to dissolve pollutants such as grease and dirt. Especially for some difficult-to-dissolve organic pollutants, glycerin can improve the cleaning effect through its hydrophilic and lipophilic properties.

[0030] Propylene glycol can effectively improve the solubility of aqueous solutions, especially for some difficult-to-dissolve oily or organic pollutants. It can act as a solvent to help detergents form stronger solubility on the surface of different pollutants, especially for grease and fat-soluble pollutants.

[0031] In order to enable the cleaning liquid to be recycled, the present invention adds an impurity cleaning agent to the formula of the cleaning liquid, which is polymerized from N-isopropylacrylamide, acrylic acid, and vinylimidazole. N-isopropylacrylamide is a conventional temperature-responsive monomer, and its polymer poly-N-isopropylacrylamide has a strong temperature sensitivity. When the temperature is low, poly-N-isopropylacrylamide exhibits hydrophilicity, which helps the polymer to dissolve in the aqueous phase; when the temperature rises, poly-N-isopropylacrylamide turns hydrophobic, so that it can be separated from water-soluble substances. In the cleaning agent formula, the introduction of poly-N-isopropylacrylamide enables the cleaning agent to self-adjust its hydrophilicity or hydrophobicity at different temperatures, and then adjusts the adsorption capacity and cleaning efficiency of pollutants according to temperature changes. However, it has two defects: 1. Its hydrophobic temperature is too low (32-34°C), which can easily reach this temperature in summer and does not meet environmental requirements; 2. After adsorbing impurities, it is difficult to separate poly (N-isopropylacrylamide) from the impurities again, especially impurities that are also water-soluble. It is impossible to separate poly (N-isopropylacrylamide) and its adsorbed impurities through hydrophilic-hydrophobic conversion, making it difficult to achieve recycling.

[0032] Therefore, the present invention adopts acrylic acid and vinyl imidazole as polymerizing groups to participate in the polymerization of N-isopropyl acrylamide. Acrylic acid is a common functional monomer with strong hydrophilicity, and can be copolymerized with other functional monomers to form a polymer with strong hydration. The introduction of acrylic acid can make the synthesized impurity cleaning agent have strong solubility in an aqueous environment, and at the same time provide a negative charge, so that the impurity cleaning agent can adsorb positively charged impurities or pollutants. By controlling the hydrophilicity and negative charge of the impurity cleaning agent, acrylic acid can adjust the adsorption capacity of the cleaning agent for water-soluble pollutants. The present invention adjusts the ratio of acrylic acid and N-isopropyl acrylamide so that the hydrophobicization temperature of the impurity cleaning agent is increased from 32-34°C to 40-45°C, thereby improving its environmental adaptability.

[0033] Vinyl imidazole is a nitrogen-containing compound that contains imidazole groups and can undergo protonation and deprotonation reactions under different pH conditions. When the pH is low, the imidazole groups will be protonated, thereby enhancing the hydrophilicity of the polymer; when the pH is high, the imidazole groups will be deprotonated and the polymer will exhibit hydrophobicity. Through this property, the polymer can adjust its hydrophilicity or hydrophobicity at different pH values, thereby effectively removing various chemical pollutants or oil stains. When the synthetic impurity cleaner adsorbs impurities in the cleaning solution and separates them, it only needs to be re-dissolved with clean water, and then adjusted to pH 9 with alkali, so that it can be separated from the impurities and precipitated from the alkali solution for recycling.

[0034] Beneficial effects of the present invention:

[0035] The present invention synthesizes a cleaning liquid for recycling and cleaning waste PU sponges, and synthesizes an impurity remover that is both temperature-responsive and pH-responsive. By adjusting the temperature and pH value, the cleaning agent can efficiently remove pollutants such as grease, chemical pollutants, and glue, while avoiding damage to the PU sponge and enabling the cleaning process to be recycled. The solution is highly innovative and environmentally friendly, meets the requirements of modern manufacturing for sustainable development and resource recycling, and has high potential. DETAILED DESCRIPTION

[0036] Liquid polyurethane, item number: 20250208001, Master Ba (Shanghai) Biotechnology Co., Ltd.

[0037] Isocyanate, CAS number: 75-13-8.

[0038] Dibutyltin chloride, CAS number: 683-18-1.

[0039] Dioctyl phthalate, CAS number: 117-84-0.

[0040] Orange peel essential oil, item number: ry-006, Anhui Rongying Biotechnology Co., Ltd.

[0041] Cocamidopropyl betaine, CAS number: 61789-40-0.

[0042] N-isopropylacrylamide, CAS number: 2210-25-5.

[0043] Acrylic acid, CAS number: 79-10-7.

[0044] Vinyl imidazole, CAS number: 1072-63-5.

[0045] Engine oil, item number: 002SP A3B4, Shandong Zeguang Lubrication Technology Co., Ltd.

[0046] Acrylic adhesive, item number: TH-896, Dongguan Yantai Chemical Technology Co., Ltd.

[0047] Industrial silicon powder, item number: M-56, Shijiazhuang Leitai Technology Co., Ltd.

[0048] Example 1

[0049] A preparation process of a PU recycled cotton composite material for automobiles, comprising the following steps:

[0050] (1) Crushing: Crushing the waste automobile interior PU sponge material obtained from an automobile dismantling plant, an automobile repair plant or an abandoned vehicle recycling system into particles of 1 mm to obtain PU sponge particles;

[0051] (2) Cleaning: Cleaning the PU sponge particles obtained in step (1) with a cleaning solution, and then dehydrating and drying to obtain clean PU sponge particles;

[0052] (3) Foaming and curing: the clean PU sponge particles obtained in step (2), liquid polyurethane, isocyanate, water, dibutyltin chloride, and dioctyl phthalate are mixed in a mass ratio of 500:250:250:12:1.25:25, and the mixture is stirred and foamed at 110° C. and 0.2 MPa for 20 min, and the temperature is raised to 165° C. and cured for 30 min to obtain the PU recycled cotton composite material for automobiles.

[0053] The formula of the cleaning solution is composed of the following raw materials:

[0054] Orange peel essential oil: 12wt%

[0055] Citric acid: 6wt%

[0056] Surfactant: 7wt%

[0057] Glycerol: 2wt%

[0058] Propylene glycol: 2wt%

[0059] Impurity cleaning agent: 7wt%

[0060] The balance is water.

[0061] The surfactant is cocamidopropyl betaine.

[0062] The preparation method of the impurity cleaning agent comprises the following steps:

[0063] S1: 10 g of N-isopropylacrylamide, 4 g of acrylic acid and 2 g of vinylimidazole were added to 200 mL of water and stirred until the monomers were completely dissolved to obtain a reaction precursor solution;

[0064] S2: Dissolve 0.5 g of ammonium persulfate in 5 mL of water to obtain an ammonium persulfate aqueous solution;

[0065] S3: placing the reaction precursor solution obtained in step S1 at 60° C. and stirring under a nitrogen atmosphere, and adding the ammonium persulfate aqueous solution obtained in step S2 dropwise thereto at a rate of 1 mL / min. After the addition is completed, reacting at a constant temperature of 60° C. for 4 hours, cooling to room temperature in a 0° C. water bath, and then heating to 45° C., filtering to obtain a filter cake, and drying to obtain the impurity cleaning agent.

[0066] Example 2

[0067] A preparation process of a PU recycled cotton composite material for automobiles, comprising the following steps:

[0068] (1) Crushing: Crushing the waste automobile interior PU sponge material obtained from an automobile dismantling plant, an automobile repair plant or an abandoned vehicle recycling system into particles of 1 mm to obtain PU sponge particles;

[0069] (2) Cleaning: Cleaning the PU sponge particles obtained in step (1) with a cleaning solution, and then dehydrating and drying to obtain clean PU sponge particles;

[0070] (3) Foaming and curing: the clean PU sponge particles obtained in step (2), liquid polyurethane, isocyanate, water, dibutyltin chloride, and dioctyl phthalate are mixed in a mass ratio of 500:250:250:12:1.25:25, and the mixture is stirred and foamed at 110° C. and 0.2 MPa for 20 min, and the temperature is raised to 165° C. and cured for 30 min to obtain the PU recycled cotton composite material for automobiles.

[0071] The formula of the cleaning solution is composed of the following raw materials:

[0072] Orange peel essential oil: 12wt%

[0073] Citric acid: 6wt%

[0074] Surfactant: 7wt%

[0075] Propylene glycol: 2wt%

[0076] Impurity cleaning agent: 7wt%

[0077] The balance is water.

[0078] The surfactant is cocamidopropyl betaine.

[0079] The preparation method of the impurity cleaning agent comprises the following steps:

[0080] S1: 10 g of N-isopropylacrylamide, 4 g of acrylic acid and 2 g of vinylimidazole were added to 200 mL of water and stirred until the monomers were completely dissolved to obtain a reaction precursor solution;

[0081] S2: Dissolve 0.5 g of ammonium persulfate in 5 mL of water to obtain an ammonium persulfate aqueous solution;

[0082] S3: placing the reaction precursor solution obtained in step S1 at 60° C. and stirring under a nitrogen atmosphere, and adding the ammonium persulfate aqueous solution obtained in step S2 dropwise thereto at a rate of 1 mL / min. After the addition is completed, reacting at a constant temperature of 60° C. for 4 hours, cooling to room temperature in a 0° C. water bath, and then heating to 45° C., filtering to obtain a filter cake, and drying to obtain the impurity cleaning agent.

[0083] Example 3

[0084] A preparation process of a PU recycled cotton composite material for automobiles, comprising the following steps:

[0085] (1) Crushing: Crushing the waste automobile interior PU sponge material obtained from an automobile dismantling plant, an automobile repair plant or an abandoned vehicle recycling system into particles of 1 mm to obtain PU sponge particles;

[0086] (2) Cleaning: Cleaning the PU sponge particles obtained in step (1) with a cleaning solution, and then dehydrating and drying to obtain clean PU sponge particles;

[0087] (3) Foaming and curing: the clean PU sponge particles obtained in step (2), liquid polyurethane, isocyanate, water, dibutyltin chloride, and dioctyl phthalate are mixed in a mass ratio of 500:250:250:12:1.25:25, and the mixture is stirred and foamed at 110° C. and 0.2 MPa for 20 min, and the temperature is raised to 165° C. and cured for 30 min to obtain the PU recycled cotton composite material for automobiles.

[0088] The formula of the cleaning solution is composed of the following raw materials:

[0089] Orange peel essential oil: 12wt%

[0090] Citric acid: 6wt%

[0091] Surfactant: 7wt%

[0092] Glycerol: 2wt%

[0093] Impurity cleaning agent: 7wt%

[0094] The balance is water.

[0095] The surfactant is cocamidopropyl betaine.

[0096] The preparation method of the impurity cleaning agent comprises the following steps:

[0097] S1: 10 g of N-isopropylacrylamide, 4 g of acrylic acid and 2 g of vinylimidazole were added to 200 mL of water and stirred until the monomers were completely dissolved to obtain a reaction precursor solution;

[0098] S2: Dissolve 0.5 g of ammonium persulfate in 5 mL of water to obtain an ammonium persulfate aqueous solution;

[0099] S3: placing the reaction precursor solution obtained in step S1 at 60° C. and stirring under a nitrogen atmosphere, and adding the ammonium persulfate aqueous solution obtained in step S2 dropwise thereto at a rate of 1 mL / min. After the addition is completed, reacting at a constant temperature of 60° C. for 4 hours, cooling to room temperature in a 0° C. water bath, and then heating to 45° C., filtering to obtain a filter cake, and drying to obtain the impurity cleaning agent.

[0100] Example 4

[0101] A preparation process of a PU recycled cotton composite material for automobiles, comprising the following steps:

[0102] (1) Crushing: Crushing the waste automobile interior PU sponge material obtained from an automobile dismantling plant, an automobile repair plant or an abandoned vehicle recycling system into particles of 1 mm to obtain PU sponge particles;

[0103] (2) Cleaning: Cleaning the PU sponge particles obtained in step (1) with a cleaning solution, and then dehydrating and drying to obtain clean PU sponge particles;

[0104] (3) Foaming and curing: the clean PU sponge particles obtained in step (2), liquid polyurethane, isocyanate, water, dibutyltin chloride, and dioctyl phthalate are mixed in a mass ratio of 500:250:250:12:1.25:25, and the mixture is stirred and foamed at 110° C. and 0.2 MPa for 20 min, and the temperature is raised to 165° C. and cured for 30 min to obtain the PU recycled cotton composite material for automobiles.

[0105] The formula of the cleaning solution is composed of the following raw materials:

[0106] Orange peel essential oil: 12wt%

[0107] Citric acid: 6wt%

[0108] Surfactant: 7wt%

[0109] Impurity cleaning agent: 7wt%

[0110] The balance is water.

[0111] The surfactant is cocamidopropyl betaine.

[0112] The preparation method of the impurity cleaning agent comprises the following steps:

[0113] S1: 10 g of N-isopropylacrylamide, 4 g of acrylic acid and 2 g of vinylimidazole were added to 200 mL of water and stirred until the monomers were completely dissolved to obtain a reaction precursor solution;

[0114] S2: Dissolve 0.5 g of ammonium persulfate in 5 mL of water to obtain an ammonium persulfate aqueous solution;

[0115] S3: placing the reaction precursor solution obtained in step S1 at 60° C. and stirring under a nitrogen atmosphere, and adding the ammonium persulfate aqueous solution obtained in step S2 dropwise thereto at a rate of 1 mL / min. After the addition is completed, reacting at a constant temperature of 60° C. for 4 hours, cooling to room temperature in a 0° C. water bath, and then heating to 45° C., filtering to obtain a filter cake, and drying to obtain the impurity cleaning agent.

[0116] Example 5

[0117] A preparation process of a PU recycled cotton composite material for automobiles, comprising the following steps:

[0118] (1) Crushing: Crushing the waste automobile interior PU sponge material obtained from an automobile dismantling plant, an automobile repair plant or an abandoned vehicle recycling system into particles of 1 mm to obtain PU sponge particles;

[0119] (2) Cleaning: Cleaning the PU sponge particles obtained in step (1) with a cleaning solution, and then dehydrating and drying to obtain clean PU sponge particles;

[0120] (3) Foaming and curing: the clean PU sponge particles obtained in step (2), liquid polyurethane, isocyanate, water, dibutyltin chloride, and dioctyl phthalate are mixed in a mass ratio of 500:250:250:12:1.25:25, and the mixture is stirred and foamed at 110° C. and 0.2 MPa for 20 min, and the temperature is raised to 165° C. and cured for 30 min to obtain the PU recycled cotton composite material for automobiles.

[0121] The formula of the cleaning solution is composed of the following raw materials:

[0122] Orange peel essential oil: 12wt%

[0123] Citric acid: 6wt%

[0124] Surfactant: 7wt%

[0125] Glycerol: 2wt%

[0126] Propylene glycol: 2wt%

[0127] Impurity cleaning agent: 7wt%

[0128] The balance is water.

[0129] The surfactant is cocamidopropyl betaine.

[0130] The preparation method of the impurity cleaning agent comprises the following steps:

[0131] S1: Add 10 g of N-isopropylacrylamide and 6 g of acrylic acid into 200 mL of water and stir until the monomers are completely dissolved to obtain a reaction precursor solution;

[0132] S2: Dissolve 0.5 g of ammonium persulfate in 5 mL of water to obtain an ammonium persulfate aqueous solution;

[0133] S3: placing the reaction precursor solution obtained in step S1 at 60° C. and stirring under a nitrogen atmosphere, and adding the ammonium persulfate aqueous solution obtained in step S2 dropwise thereto at a rate of 1 mL / min. After the addition is completed, reacting at a constant temperature of 60° C. for 4 hours, cooling to room temperature in a 0° C. water bath, and then heating to 45° C., filtering to obtain a filter cake, and drying to obtain the impurity cleaning agent.

[0134] Example 6

[0135] A preparation process of a PU recycled cotton composite material for automobiles, comprising the following steps:

[0136] (1) Crushing: Crushing the waste automobile interior PU sponge material obtained from an automobile dismantling plant, an automobile repair plant or an abandoned vehicle recycling system into particles of 1 mm to obtain PU sponge particles;

[0137] (2) Cleaning: Cleaning the PU sponge particles obtained in step (1) with a cleaning solution, and then dehydrating and drying to obtain clean PU sponge particles;

[0138] (3) Foaming and curing: the clean PU sponge particles obtained in step (2), liquid polyurethane, isocyanate, water, dibutyltin chloride, and dioctyl phthalate are mixed in a mass ratio of 500:250:250:12:1.25:25, and the mixture is stirred and foamed at 110° C. and 0.2 MPa for 20 min, and the temperature is raised to 165° C. and cured for 30 min to obtain the PU recycled cotton composite material for automobiles.

[0139] The formula of the cleaning solution is composed of the following raw materials:

[0140] Orange peel essential oil: 12wt%

[0141] Citric acid: 6wt%

[0142] Surfactant: 7wt%

[0143] Glycerol: 2wt%

[0144] Propylene glycol: 2wt%

[0145] Impurity cleaning agent: 7wt%

[0146] The balance is water.

[0147] The surfactant is cocamidopropyl betaine.

[0148] The preparation method of the impurity cleaning agent comprises the following steps:

[0149] S1: 10 g of N-isopropylacrylamide and 6 g of vinylimidazole were added to 200 mL of water and stirred until the monomers were completely dissolved to obtain a reaction precursor solution;

[0150] S2: Dissolve 0.5 g of ammonium persulfate in 5 mL of water to obtain an ammonium persulfate aqueous solution;

[0151] S3: placing the reaction precursor solution obtained in step S1 at 60° C. and stirring under a nitrogen atmosphere, and adding the ammonium persulfate aqueous solution obtained in step S2 dropwise thereto at a rate of 1 mL / min. After the addition is completed, reacting at a constant temperature of 60° C. for 4 hours, cooling to room temperature in a 0° C. water bath, and then heating to 45° C., filtering to obtain a filter cake, and drying to obtain the impurity cleaning agent.

[0152] Example 7

[0153] A preparation process of a PU recycled cotton composite material for automobiles, comprising the following steps:

[0154] (1) Crushing: Crushing the waste automobile interior PU sponge material obtained from an automobile dismantling plant, an automobile repair plant or an abandoned vehicle recycling system into particles of 1 mm to obtain PU sponge particles;

[0155] (2) Cleaning: Cleaning the PU sponge particles obtained in step (1) with a cleaning solution, and then dehydrating and drying to obtain clean PU sponge particles;

[0156] (3) Foaming and curing: the clean PU sponge particles obtained in step (2), liquid polyurethane, isocyanate, water, dibutyltin chloride, and dioctyl phthalate are mixed in a mass ratio of 500:250:250:12:1.25:25, and the mixture is stirred and foamed at 110° C. and 0.2 MPa for 20 min, and the temperature is raised to 165° C. and cured for 30 min to obtain the PU recycled cotton composite material for automobiles.

[0157] The formula of the cleaning solution is composed of the following raw materials:

[0158] Orange peel essential oil: 12wt%

[0159] Citric acid: 6wt%

[0160] Surfactant: 7wt%

[0161] Glycerol: 2wt%

[0162] Propylene glycol: 2wt%

[0163] Impurity cleaning agent: 7wt%

[0164] The balance is water.

[0165] The surfactant is cocamidopropyl betaine.

[0166] The impurity cleaning agent is N-isopropyl acrylamide.

[0167] Comparative Example 1

[0168] A preparation process of a PU recycled cotton composite material for automobiles, comprising the following steps:

[0169] (1) Crushing: Crushing the waste automobile interior PU sponge material obtained from an automobile dismantling plant, an automobile repair plant or an abandoned vehicle recycling system into particles of 1 mm to obtain PU sponge particles;

[0170] (2) Cleaning: Cleaning the PU sponge particles obtained in step (1) with a cleaning solution, and then dehydrating and drying to obtain clean PU sponge particles;

[0171] (3) Foaming and curing: the clean PU sponge particles obtained in step (2), liquid polyurethane, isocyanate, water, dibutyltin chloride, and dioctyl phthalate are mixed in a mass ratio of 500:250:250:12:1.25:25, and the mixture is stirred and foamed at 110° C. and 0.2 MPa for 20 min, and the temperature is raised to 165° C. and cured for 30 min to obtain the PU recycled cotton composite material for automobiles.

[0172] The formula of the cleaning solution is composed of the following raw materials:

[0173] Orange peel essential oil: 12wt%

[0174] Citric acid: 6wt%

[0175] Surfactant: 7wt%

[0176] Glycerol: 2wt%

[0177] Propylene glycol: 2wt%

[0178] The balance is water.

[0179] The surfactant is cocamidopropyl betaine.

[0180] Test Example 1

[0181] Cleaning ability test: Take 1g of the clean PU sponge particles obtained in step (2) of the embodiment and 1g of the simulated pollutant respectively, mix the simulated pollutant and the clean PU sponge particles obtained in step (2) of the embodiment thoroughly, and then place them in a temperature-controlled oven at 60°C and dry them for 24-36h to obtain the contaminated PU sponge. Weigh the mass and record it as M 0 ; Then, the contaminated PU sponge was placed in 10g of the cleaning solution provided in the embodiment, stirred at 200r / min for 30min, taken out, dehydrated, and then placed in a temperature-controlled oven at 60°C for 24-36h, and the mass was weighed and recorded as M 1 .

[0182] The simulated pollutant is prepared by mixing 0.2 g of engine oil, 0.4 g of acrylic glue, and 0.4 g of industrial silicon powder.

[0183] Decontamination efficiency = (M 0 -M 1 ) / mass of simulated pollutants*100%; the results are shown in Table 1.

[0184] Table 1: Cleaning ability test results

[0185] Decontamination efficiency / % Example 1 99.4 Example 2 94.6 Example 3 93.7 Example 4 82.1

[0186] Test Example 2

[0187] Cycle performance test:

[0188] (1) Cleaning ability test: Take 1 g of the clean PU sponge particles obtained in step (2) of the embodiment and 1 g of the simulated pollutant, mix the simulated pollutant and the clean PU sponge particles obtained in step (2) of the embodiment thoroughly, and then place them in a temperature-controlled oven at 60° C. and dry them for 24-36 h to obtain the contaminated PU sponge. Weigh the mass and record it as M. 0 ; Then, the contaminated PU sponge was placed in 10g of the cleaning solution provided in the embodiment, stirred at 200r / min for 30min, taken out, dehydrated, and then placed in a temperature-controlled oven at 60°C for 24-36h, and the mass was weighed and recorded as M 1 .

[0189] The simulated pollutant is prepared by mixing 0.2 g of engine oil, 0.4 g of acrylic glue, and 0.4 g of industrial silicon powder.

[0190] Decontamination efficiency = (M 0 -M 1 ) / mass of simulated pollutants*100%;

[0191] (2) Collect the residual cleaning liquid from step (1), heat it to 45° C., and filter to obtain filtrate A and filter residue A; mix filter residue A with 10 g of water, adjust the pH to 9 with sodium hydroxide, stir for 15 min, filter to obtain filter residue B, mix filter residue B and filtrate A, and stir at room temperature for 15 min to obtain a secondary cleaning liquid; repeat the cleaning ability test of step (1) with the secondary cleaning liquid, and calculate the decontamination efficiency;

[0192] (3) Repeat steps (1) and (2) to obtain three, four, and five cleaning solutions, and calculate the decontamination efficiency of the fifth cleaning solution; the results are shown in Table 2.

[0193] Table 2: Cyclic performance test results

[0194] Decontamination efficiency of the fifth cleaning solution / % Example 1 96.8 Example 5 32.6 Example 6 67.2 Example 7 28.1 Comparative Example 1 9.2

[0195] From the test results in Table 1 and Table 2, it can be seen that the cleaning solution prepared in Example 1 has the best decontamination efficiency and cyclic decontamination performance. In order to improve the cleaning efficiency of the cleaning solution, glycerol and propylene glycol are added to the formula of the cleaning solution in the present invention.

[0196] Glycerin can increase the viscosity of aqueous solutions, which helps improve the detergent's ability to dissolve pollutants such as grease and dirt. Especially for some difficult-to-dissolve organic pollutants, glycerin can improve the cleaning effect through its hydrophilic and lipophilic properties.

[0197] Propylene glycol can effectively improve the solubility of aqueous solutions, especially for some difficult-to-dissolve oily or organic pollutants. It can act as a solvent to help detergents form stronger solubility on the surface of different pollutants, especially for grease and fat-soluble pollutants.

[0198] The combination of the two can significantly enhance the solvent's solubility, especially for cleaning grease, chemical pollutants and some organic pollutants.

[0199] In order to enable the cleaning liquid to be recycled, the present invention adds an impurity cleaning agent to the formula of the cleaning liquid, which is polymerized from N-isopropylacrylamide, acrylic acid, and vinylimidazole. N-isopropylacrylamide is a conventional temperature-responsive monomer, and its polymer poly-N-isopropylacrylamide has a strong temperature sensitivity. When the temperature is low, poly-N-isopropylacrylamide exhibits hydrophilicity, which helps the polymer to dissolve in the aqueous phase; when the temperature rises, poly-N-isopropylacrylamide turns hydrophobic, so that it can be separated from water-soluble substances. In the cleaning agent formula, the introduction of poly-N-isopropylacrylamide enables the cleaning agent to self-adjust its hydrophilicity or hydrophobicity at different temperatures, and then adjusts the adsorption capacity and cleaning efficiency of pollutants according to temperature changes.

[0200] Acrylic acid is a common functional monomer with strong hydrophilicity and can copolymerize with other functional monomers to form a polymer with strong hydration. The introduction of acrylic acid can make the synthesized impurity cleaning agent have strong solubility in an aqueous environment, and at the same time provide a negative charge, so that the impurity cleaning agent can adsorb positively charged impurities or pollutants. By controlling the hydrophilicity and negative charge of the impurity cleaning agent, acrylic acid can adjust the adsorption capacity of the cleaning agent for water-soluble pollutants. The present invention adjusts the ratio of acrylic acid and N-isopropylacrylamide so that the hydrophobicization temperature of the impurity cleaning agent is increased from 32-34°C to 40-45°C, thereby improving its environmental adaptability.

[0201] Vinyl imidazole is a nitrogen-containing compound that contains imidazole groups and can undergo protonation and deprotonation reactions under different pH conditions. When the pH is low, the imidazole groups will be protonated, thereby enhancing the hydrophilicity of the polymer; when the pH is high, the imidazole groups will be deprotonated and the polymer will exhibit hydrophobicity. Through this property, the polymer can adjust its hydrophilicity or hydrophobicity at different pH values, thereby effectively removing various chemical pollutants or oil stains. When the synthetic impurity cleaner adsorbs impurities in the cleaning solution and separates them, it only needs to be re-dissolved with clean water, and then adjusted to pH 9 with alkali, so that it can be separated from the impurities and precipitated from the alkali solution for recycling.

Claims

1. A preparation process of a PU recycled cotton composite material for automobiles, characterized in that: The following steps are involved: (1) Crushing: crushing the waste PU sponge to obtain PU sponge particles; (2) Cleaning: Cleaning the PU sponge particles obtained in step (1) with a cleaning solution; (3) Foaming and curing: The clean PU sponge particles and liquid polyurethane obtained in step (2) are mixed and foamed and cured to obtain the PU recycled cotton composite material for automobiles.

2. The preparation process of the PU recycled cotton composite material for automobiles as claimed in claim 1, characterized in that: The specific steps of crushing are: crushing the waste automobile interior PU sponge material obtained from an automobile dismantling plant, an automobile repair plant or an abandoned vehicle recycling system into particles of 1-2 mm to obtain PU sponge particles.

3. The preparation process of the PU recycled cotton composite material for automobiles as claimed in claim 1, characterized in that: The specific steps of cleaning are: using a cleaning liquid to clean the PU sponge particles obtained in step (1), and then dehydrating and drying to obtain clean PU sponge particles.

4. The preparation process of the PU recycled cotton composite material for automobiles as claimed in claim 1, characterized in that: The specific steps of foaming and curing are: the clean PU sponge particles obtained in step (2), liquid polyurethane, isocyanate, water, dibutyltin chloride, and dioctyl phthalate are mixed in a mass ratio of 500: (250-500): (250-500): (10-15): (1-3): (20-30), and the mixture is stirred and foamed at 100-120° C. and 0.1-0.3 Mpa for 15-30 minutes, and the mixture is heated to 160-170° C. and cured for 15-60 minutes.

5. The preparation process of the PU recycled cotton composite material for automobiles as claimed in claim 3, characterized in that: The formula of the cleaning liquid is composed of the following raw materials: orange peel essential oil: 10-15wt%, citric acid: 5-8wt%, surfactant: 5-9wt%, glycerin: 2-3wt%, propylene glycol: 1-2wt%, impurity cleaning agent: 6-8wt%, and the balance is water.

6. The preparation process of the PU recycled cotton composite material for automobiles as claimed in claim 5, characterized in that: The surfactant is at least one of polyethylene glycol caprylate, octylphenoxyethanol, sorbitan monooleate, and cocamidopropyl betaine.

7. The preparation process of the PU recycled cotton composite material for automobiles as claimed in claim 5, characterized in that: The preparation method of the impurity cleaning agent comprises the following steps: S1: adding 9-11 g of N-isopropylacrylamide, 3.5-4.5 g of acrylic acid and 1-3 g of vinylimidazole to 180-220 mL of water, stirring until the monomers are completely dissolved to obtain a reaction precursor solution; S2: dissolving 0.4-0.6 g of ammonium persulfate in 4-6 mL of water to obtain an ammonium persulfate aqueous solution; S3: placing the reaction precursor solution obtained in step S1 at 55-70° C. and stirring under a nitrogen atmosphere, and adding the ammonium persulfate aqueous solution obtained in step S2 dropwise thereto at a rate of 0.5-1.5 mL / min. After the addition is completed, reacting at a constant temperature of 55-70° C. for 3-5 hours, cooling to room temperature in a 0-4° C. water bath, and then heating to 40-45° C., filtering to obtain a filter cake, and drying to obtain the impurity cleaning agent.

8. A PU recycled cotton composite material for automobiles, characterized in that: The composite material is prepared by the preparation process of the PU recycled cotton composite material for automobiles according to any one of claims 1 to 7.