CN114920985B - Method for recycling low-molecular polyol by catalyzing and degrading spandex through rare earth - Google Patents
Method for recycling low-molecular polyol by catalyzing and degrading spandex through rare earth Download PDFInfo
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J11/00—Recovery or working-up of waste materials
- C08J11/04—Recovery or working-up of waste materials of polymers
- C08J11/10—Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation
- C08J11/16—Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation by treatment with inorganic material
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/002—Mixed oxides other than spinels, e.g. perovskite
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/10—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of rare earths
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J11/00—Recovery or working-up of waste materials
- C08J11/04—Recovery or working-up of waste materials of polymers
- C08J11/10—Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation
- C08J11/18—Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation by treatment with organic material
- C08J11/22—Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation by treatment with organic material by treatment with organic oxygen-containing compounds
- C08J11/24—Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation by treatment with organic material by treatment with organic oxygen-containing compounds containing hydroxyl groups
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2523/00—Constitutive chemical elements of heterogeneous catalysts
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2375/00—Characterised by the use of polyureas or polyurethanes; Derivatives of such polymers
- C08J2375/04—Polyurethanes
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
- Y02W30/62—Plastics recycling; Rubber recycling
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Abstract
The invention discloses a method for recycling low-molecular polyol by catalyzing and degrading spandex through rare earth. The method comprises the following steps: s1, putting the sheared waste spandex staple into a mixing container, adding a rare earth catalyst, a degradation agent and deionized water, mixing and stirring, wherein the rare earth catalyst is dysprosium oxide doped strontium aluminate, and obtaining a fully-infiltrated wet waste spandex staple component; s2, putting wet waste spandex short-yarn components into a double-screw extruder, and shearing and extruding to obtain a mixture containing low-molecular polyol and water; s3, adding anhydrous calcium chloride into the mixture obtained in the step S2, stirring to remove water, and performing vacuum filtration to obtain the colorless transparent low-molecular polyol. The method provided by the invention avoids the problems of toxic organic solvents, large addition amount of degradation agents and high reaction temperature in the traditional chemical recovery method. The method is environment-friendly and has low post-treatment cost; meanwhile, the required reaction temperature is low, so that the energy consumption can be effectively reduced, and the safety is improved.
Description
Technical field:
the invention relates to the technical field of three-waste treatment, in particular to a method for recycling low-molecular polyol by catalyzing and degrading spandex through rare earth.
The background technology is as follows:
the polyurethane is a polymer fiber with high rebound, high elongation and low modulus prepared by taking polyurethane as a raw material and carrying out dry spinning or melt spinning. The polyurethane has excellent elasticity, and can restore to original shape after relaxation, and has the characteristics of softness, comfort, good chemical resistance, oil resistance, sweat resistance, moth resistance, mildew resistance and the like, and can be widely applied to the fields of clothing, ornaments, medical materials and the like. However, a large amount of waste silk is generated in the production and use processes of spandex, and the recycling methods of the waste silk at present mainly include the following methods: energy recovery method, physical recovery method, chemical recovery method.
The energy recovery method mainly relies on incineration to recycle the energy obtained from the spandex waste, and the method can reutilize the spandex waste to a certain extent and plays a role in reducing the volume of waste spandex to a great extent, but also causes a series of secondary pollution problems, and a lot of gases polluting the environment are generated in the recovery process. The physical recovery method is mainly a method for reutilizing polyurethane without changing the composition of substances and damaging the chemical structure of a high polymer, and at present, hot press molding, bonding processing molding, extrusion molding and filling are commonly used, and the terminal products prepared by the method have low performance and limited application range. The chemical recovery method is to change the waste spandex into a reusable raw material, such as a liquid oligomer or even a small molecular organic compound, under the change of chemical methods such as alcohol, ammonia, water, alkali, heat and the like, mainly by hydrolysis, alcoholysis, aminolysis and the like, but the method has the common problems of high degradation reaction temperature, large degradation agent consumption, organic solvent and the like in the process.
Therefore, the efficient and reasonable recycling of the spandex waste silk and the reduction of the environmental pollution in the process are problems to be solved in the industry.
The invention comprises the following steps:
the invention solves the problems existing in the prior art, and provides a method for recycling low-molecular polyol by catalyzing and degrading spandex by rare earth. The method is environment-friendly and has low post-treatment cost; meanwhile, the required reaction temperature is low, so that the energy consumption can be effectively reduced, and the safety is improved.
The invention aims to provide a method for recycling low-molecular polyol by catalyzing and degrading spandex through rare earth, which comprises the following steps:
s1, putting the sheared waste spandex staple into a mixing container, adding a rare earth catalyst, a degradation agent and deionized water, mixing and stirring for 5-10 min, wherein the rare earth catalyst is dysprosium oxide doped strontium aluminate, and obtaining a fully-infiltrated wet waste spandex staple component;
s2, putting wet waste spandex short-yarn components into a double-screw extruder, and shearing and extruding to obtain a mixture containing low-molecular polyol and water;
s3, adding anhydrous calcium chloride into the mixture obtained in the step S2, stirring to remove water, and performing vacuum filtration to obtain the colorless transparent low-molecular polyol.
Preferably, the dysprosium oxide doped strontium aluminate in step S1 has a doping amount of 1.0wt% to 3.0wt%.
The dysprosium oxide doped strontium aluminate is prepared by the following steps: srCO 3 、Al 2 O 3 、Dy 2 O 3 、H 3 BO 3 And placing the sufficient activated carbon into a crucible for grinding, drying, roasting for 3-5 hours at 1200-1500 ℃, naturally cooling, and crushing to obtain dysprosium oxide doped strontium aluminate. SrCO 3 、Al 2 O 3 、Dy 2 O 3 And H 3 BO 3 The mass ratio of (2) is 29.6:20.4:74.6:1.
The dysprosium oxide doped strontium aluminate catalytic waste spandex is used for recycling low-molecular polyol, and the reaction principle is as follows: dysprosium oxide doped strontium aluminate is not stable enough and undergoes the following hydrolysis in the presence of moisture:
SrAl 2 O 4 ：Dy 3+ +4H 2 O→Sr(OH) 2 +2Al(OH) 3 +Dy 3+
under the conditions of moisture and heating, the hydrolysis reaction can destroy the crystal structure of dysprosium oxide doped strontium aluminate to ensure Dy 3+ The rare earth ions escape out of the crystal lattice, and the rare earth ions and the diethanol generate a synergistic effect to accelerate the degradation of the spandex, and simultaneously the degradation is further accelerated under the high-speed high-temperature shearing of double screws to form the low-molecular polyol.
Preferably, the mass ratio of the waste spandex staple, the rare earth catalyst, the degradation agent and the deionized water in the step S1 is 1 (0.01-0.02): (0.005-0.02) and (0.05-0.1).
Preferably, the length of the waste spandex staple in the step S1 is 0.5-1 cm.
Preferably, the degradation agent in step S1 is diethyl acetal.
Preferably, the length-diameter ratio of the twin-screw extruder in the step S2 is 50-70, the extrusion temperature is 140-180 ℃, and the shearing rate is 200-300 r/min.
Preferably, the mass ratio of the anhydrous calcium chloride to the mixture in the step S3 is (0.02-0.05): 1.
preferably, the specific conditions for stirring and dewatering in the step S3 are as follows: stirring at high speed of 50-200 r/min for 0.5-1 h to remove water.
The invention also protects application of the rare earth catalyst in catalyzing and degrading spandex to recycle low-molecular polyol, wherein the rare earth catalyst is dysprosium oxide doped strontium aluminate.
Compared with the prior art, the invention has the following advantages: the method provided by the invention avoids the problems of large addition amount of the degradation agent and long process time caused by toxic organic solvents used in the traditional chemical recovery method. The rare earth catalyst and the degradation agent are used in the method in small amounts, no toxic or harmful solvent is used in the whole process, the safety is high, the environment is friendly, the recovery rate is high, and the post-treatment cost is low; meanwhile, a double-screw extruder high-speed shearing process is adopted for degradation reaction, the heating process time is short, and the energy consumption is low. The invention accords with the development direction of the green carbon neutralization industry and provides a new idea for recycling waste spandex.
Description of the drawings:
FIG. 1 is a gel permeation chromatogram of the product of example 2.
The specific embodiment is as follows:
the following examples are further illustrative of the invention and are not intended to be limiting thereof.
Unless specifically stated, the experimental materials and reagents in the present invention are all commercially available products conventional in the art.
In the following examples, dysprosium oxide doped strontium aluminate was prepared by the following steps: 148g SrCO 3 、102g Al 2 O 3 、373g Dy 2 O 3 、5g H 3 BO 3 And 500g of active carbon are put into a crucible for grinding, are baked for 4 hours at 1350 ℃ after being dried, are naturally cooled and are crushed, and the dysprosium oxide doped strontium aluminate is obtained.
Example 1
A method for recycling low-molecular polyol by catalyzing waste spandex through rare earth comprises the following steps:
s1, cutting 1000g of waste lycra spandex cloth into 0.5cm short filaments, putting the short filaments into a high-speed mixer, adding 10g of dysprosium oxide doped strontium aluminate, 5g of diethylene glycol and 50g of deionized water, mixing and stirring for 5min to obtain a fully-infiltrated wet waste spandex short filament component, wherein the doping amount of dysprosium oxide in the dysprosium oxide doped strontium aluminate is 2.0wt%.
S2, putting the wet waste spandex short-yarn component into a double-screw extruder with the length-diameter ratio of 50, performing high-speed shearing extrusion at the temperature of 140 ℃ at the shearing rate of 200r/min, and obtaining 600g of mixture containing low-molecular polyol and a small amount of water at a discharge hole.
S3, adding 12g of anhydrous calcium chloride into the mixture obtained in the step S2, stirring at a high speed of 50r/min for 0.5h, and carrying out reduced pressure suction filtration on the components after water removal to obtain 580g of colorless transparent low-molecular polyester polyol.
Example 2
A method for recycling low-molecular polyol by catalyzing waste spandex through rare earth comprises the following steps:
s1, cutting 1000g of waste lycra spandex fabric into 1cm short filaments, putting the 1cm short filaments into a high-speed mixer, adding 20g of dysprosium oxide doped strontium aluminate, 20g of diethyl acetal and 100g of deionized water, mixing and stirring for 10min, and obtaining a fully-infiltrated wet waste spandex short filament component, wherein the doping amount of dysprosium oxide in the dysprosium oxide doped strontium aluminate is 2.0wt%.
S2, putting the wet waste spandex short-yarn component into a double-screw extruder with the length-diameter ratio of 70, performing high-speed shearing extrusion at 180 ℃ at a shearing rate of 300r/min, and obtaining 700g of mixture containing low-molecular polyol and a small amount of water at a discharge hole.
S3, adding 35g of anhydrous calcium chloride into the mixture obtained in the step S2, stirring at a high speed of 200r/min for 1h to remove water, and performing vacuum filtration on the components to obtain 690g of colorless transparent low-molecular polyester polyol.
GPC measurement was performed on the obtained low molecular weight polyester polyol as shown in FIG. 1 and Table 1:
TABLE 1
As can be seen from fig. 1 and table 1, the number average molecular weight mn=1156 kDa, the weight average molecular weight mw=2236 kDa, the polydispersity pdi=1.93, and the low molecular weight polyester polyol is a polyester polyol having a molecular weight of about 2000.
Comparative example 1
The same as in example 2, except that: s1, cutting 1000g of waste lycra spandex fabric into 1cm short filaments, putting the 1cm short filaments into a high-speed mixer, adding 40g of dysprosium oxide doped strontium aluminate and 100g of deionized water, mixing and stirring for 10min to obtain a fully-infiltrated wet waste spandex short filament component, wherein the doping amount of dysprosium oxide in the dysprosium oxide doped strontium aluminate is 2.0wt%.
360g of a colorless transparent low-molecular polyol were obtained.
Comparative example 2
The same as in example 2, except that: s1, cutting 1000g of waste lycra spandex cloth into 1cm short filaments, putting the short filaments into a high-speed mixer, adding 40g of diethyl acetal and 100g of deionized water, mixing and stirring for 10min, and obtaining the fully-infiltrated wet waste spandex short filament component.
310g of a colorless transparent low-molecular polyol were obtained.
Comparative example 3
The same as in example 2, except that: s2, putting wet waste lycra spandex cloth components into a three-mouth bottle, starting condensation circulation under the protection of nitrogen, and carrying out stirring and cracking reaction at the speed of 300r/min at 180 ℃ for 2 hours to obtain a mixture containing low-molecular polyester polyol and water.
420g of a colorless transparent low-molecular polyol was obtained.
When the obtained products of example 2 are completely the same as those of comparative examples 1 to 3, the recovery rate of the low molecular polyol is far lower than that of the dysprosium doped strontium aluminate and the diethanol of example 2 by the combined action of the dysprosium doped strontium aluminate and the diethanol of comparative example 1 and comparative example 2 by the treatment of the dysprosium doped strontium aluminate and the diethanol of comparative example 2 respectively, and the recovery rate of the product obtained by the decomposition reaction of comparative example 3 by stirring is far lower than that of the product obtained by the decomposition reaction of example 2 by adopting a high-speed shearing process of a double screw extruder, and meanwhile, the heating process time of example 2 is short and the energy consumption is low.
Example 3
A method for recycling low-molecular polyol by catalyzing waste spandex through rare earth comprises the following steps:
s1, cutting 1000g of waste lycra spandex cloth into 0.8cm short filaments, putting the short filaments into a high-speed mixer, adding 15g of dysprosium oxide doped strontium aluminate, 10g of diethylene glycol and 80g of deionized water, mixing and stirring for 8min, and obtaining a fully-infiltrated wet waste spandex short filament component.
S2, putting the wet waste spandex short-yarn component into a double-screw extruder with the length-diameter ratio of 60, and performing high-speed shearing extrusion at 160 ℃ at a shearing rate of 250r/min to obtain 650g of mixture containing low-molecular polyol and a small amount of water at a discharge port.
S3, adding 19.5g of anhydrous calcium chloride into the mixture obtained in the step S2, stirring at a high speed of 250r/min for 0.8h to remove water, and performing vacuum filtration on the components to obtain 710g of colorless transparent low-molecular polyol.
The above embodiments are only described to assist in understanding the technical solution of the present invention and its core idea, and it should be noted that it will be obvious to those skilled in the art that several improvements and modifications can be made to the present invention without departing from the principle of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.
Claims (4)
1. The method for recycling low-molecular polyol by catalyzing and degrading spandex through rare earth is characterized by comprising the following steps of:
s1, putting the waste spandex staple subjected to shearing treatment into a mixing container, adding a rare earth catalyst, a degradation agent and deionized water, mixing and stirring, wherein the rare earth catalyst is dysprosium oxide doped strontium aluminate to obtain a fully-infiltrated wet waste spandex staple component, the degradation agent is diethanol, the doping amount of dysprosium oxide in the dysprosium oxide doped strontium aluminate is 1.0-3.0 wt%, and the mass ratio of the waste spandex staple, the rare earth catalyst, the degradation agent and the deionized water is (0.01-0.02): (0.005-0.02): (0.05-0.1);
s2, putting wet waste spandex short-yarn components into a double-screw extruder, and shearing and extruding to obtain a mixture containing low-molecular polyol and water, wherein the length-diameter ratio of the double-screw extruder is 50-70, the extruding temperature is 140-180 ℃, and the shearing rate is 200-300 r/min;
s3, adding anhydrous calcium chloride into the mixture obtained in the step S2, stirring and removing water, and then performing vacuum filtration to obtain colorless and transparent low-molecular polyol, wherein the mass ratio of the anhydrous calcium chloride to the mixture is (0.02-0.05): 1.
2. the method for recycling low-molecular polyol by catalyzing and degrading spandex through rare earth according to claim 1, wherein the length of the waste spandex staple in the step S1 is 0.5-1 cm.
3. The method for recycling low molecular weight polyol by rare earth catalytic degradation of spandex according to claim 1, wherein the specific conditions of stirring and dewatering in the step S3 are as follows: stirring at a high speed of 50-200 r/min for 0.5-1 h to remove water.
4. The application of the rare earth catalyst in catalyzing and degrading spandex to recycle low-molecular polyol is characterized in that the rare earth catalyst is dysprosium oxide doped strontium aluminate.
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| CN110951066A (en) * | 2019-12-09 | 2020-04-03 | 江苏国胶新材料有限公司 | Preparation method of polyether polyol |
| CN111909336A (en) * | 2020-07-15 | 2020-11-10 | 芦娜 | Degradation method of polyurethane solid waste |
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2022
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Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN101525406A (en) * | 2009-03-31 | 2009-09-09 | 上海联景聚氨酯工业有限公司 | Technique for manufacturing thermoplastic polyurethane (TPU) with waste polyurethane fiber |
| CN105061718A (en) * | 2015-08-11 | 2015-11-18 | 浙江恒丰新材料有限公司 | Method for preparing polyols for polyurethane through liquefication of forestry and agricultural residues |
| CN106279760A (en) * | 2016-08-12 | 2017-01-04 | 成都威迪斯达科技有限公司 | A kind of recovery processing technique of waste polyurethane |
| CN107286369A (en) * | 2017-08-02 | 2017-10-24 | 江苏世丰新材料有限公司 | A kind of method that acidolysis soft polyurethane foam discarded object generates polyalcohol |
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