Method for synthesizing high-viscosity polyether through polyhydric alcohol composite catalysis
By using a three-stage modular reaction design based on a polyol composite catalyst system, the bottleneck in the preparation of ultra-high viscosity polyethers has been solved, enabling efficient and environmentally friendly synthesis of ultra-high viscosity polyethers, which is suitable for high-end industrial applications.
Patent Information
- Application Number
- CN202510983432.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-17
- Publication Date
- 2025-10-21
AI Technical Summary
Existing processes for preparing ultra-high viscosity polyethers face challenges such as limited viscosity improvement, low reaction efficiency, and insufficient environmental friendliness. In particular, high-end applications suffer from issues such as unstable molecular weight distribution and metal residues.
A hybrid catalytic system consisting of a bimetallic catalyst, an organic imidazole catalyst, and nano-graphene oxide was used to achieve efficient synthesis of ultra-high viscosity polyethers through a three-stage modular reaction involving polyol initiation, chain growth, and polymer chain end modification, combined with precise temperature control.
The synthesized polyether products have ultra-high viscosity, stable performance, and excellent thermal stability, making them suitable for high-viscosity lubricants, high-strength adhesives, and high-temperature sealing materials. They are also environmentally friendly, which aligns with the trend of green chemical development.
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Figure CN120818136A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of catalytic synthesis of polymer materials, in particular to a method for synthesizing high-viscosity polyether through composite catalysis of polyols. Background Art
[0002] As a key member of polymer materials, ultra-high viscosity polyether plays an irreplaceable role in modern industry. It is widely used in high-end lubricants, high-strength structural adhesives, high-temperature sealing materials, and new electronic component packaging.
[0003] However, the existing preparation process of ultra-high viscosity polyether faces the following technical difficulties:
[0004] 1. Limited viscosity increase: As the molecular weight increases, traditional polymerization processes are difficult to effectively control the molecular weight distribution, resulting in limited viscosity increase and unstable product performance;
[0005] 2. Low reaction efficiency: High molecular weight polyether has a low reaction rate in conventional catalytic systems, which easily produces side reactions such as cross-linking and decomposition, increasing energy consumption;
[0006] 3. Insufficient environmental friendliness: Existing metal catalyst systems may produce metal residues and cannot meet the stringent requirements of high-end applications such as medical and electronic fields. Summary of the Invention
[0007] In view of the above-mentioned shortcomings of the prior art, the object of the present invention is to provide a method for synthesizing high-viscosity polyethers using a polyol composite catalysis to synthesize polyether products with ultra-high viscosity, stable performance, good reliability and excellent thermal stability.
[0008] A method for synthesizing high-viscosity polyether using a polyol composite catalysis comprises the following steps:
[0009] S1 prepares a mixed catalyst for standby use;
[0010] The mixed catalyst is composed of a bimetallic catalyst, an organic imidazole catalyst and nano-graphene oxide;
[0011] S2 uses polyol as an initiator and reacts with ethylene oxide under the action of a mixed catalyst system to produce an initial low molecular weight polyether;
[0012] S3 continues to introduce mixed monomers to react until the molecular weight of the polyether increases to 5000-10000;
[0013] S4 introduces functional monomers to modify the properties of the polyether chain ends to synthesize high-viscosity polyether.
[0014] As a further improvement of the above scheme, the method for preparing the mixed catalyst is specifically performed as follows:
[0015] S11 adds cobalt salt, zinc salt, nano-graphene oxide and methanol into a dry and clean reactor and stirs until the state is uniform;
[0016] S12: 1-methylimidazole and methanol are pumped into a dropping tank and stirred to obtain a 1-methylimidazole / methanol solution;
[0017] S13: Control the temperature in the reactor to <50°C, slowly add 1-methylimidazole / methanol solution dropwise to the reactor, and stir for 30 minutes;
[0018] S14 continues to pump triethanolamine into the dropping tank, and then drops it into the reactor;
[0019] After the addition of S15 was completed, the ultrasonic frequency was set to 30 kHz and the stirring time was 120 min;
[0020] S16 is subjected to cooling, filtering and drying to obtain a mixed catalyst.
[0021] As a further improvement of the above solution, the weight ratio of the cobalt salt, zinc salt, nano-graphite oxide and methanol is 4-6:10-15:1:50-70. The weight ratio of 1-methylimidazole and methanol is 1:15-20.
[0022] As a further improvement of the above solution, a mixed catalyst consisting of a cobalt-zinc bimetallic catalyst, a 1-methylimidazole catalyst and nano-graphene oxide is obtained through cooling, filtering and drying.
[0023] The present invention establishes a synergistic catalytic system with a bimetallic catalyst as a main catalyst, an organic imidazole catalyst as a cocatalyst, and nanographene as a dispersing aid to improve the efficiency of polyether synthesis. The cobalt-zinc bimetallic catalyst has excellent low-temperature activity and can catalyze polymerization reactions at lower temperatures, thereby reducing the energy consumption of the synthesis process. The surface of the bimetallic catalyst is modified with a low-toxic organic amine, thereby further improving its initiation ability for polyols. In addition, the bimetallic catalyst is a complex with good activity and stability, overcoming the problem of metal residue. The organic imidazole catalyst plays a role in improving the ring-opening efficiency of epoxide monomers during the synthesis of polyethers. In addition, nanographene oxide has high thermal conductivity and a two-dimensional structure composed of a single layer of carbon atoms, and its surface is rich in oxygen-containing functional groups such as hydroxyl and carboxyl groups, which can improve the dispersibility of the catalyst in the polyol matrix, thereby reducing local overheating and further reducing the occurrence of side reactions such as cross-linking and chain scission.
[0024] As a further improvement of the above solution, the polyol is glycerol or pentaerythritol;
[0025] The method for generating the initial low molecular weight polyether is specifically performed as follows:
[0026] S21 Add pentaerythritol and mixed catalyst into a dry and clean reactor, heat to 60-70°C, and stir for 30 minutes;
[0027] S22 controls the reaction temperature to 60-70°C and the pressure to 1-2 MPa, slowly introduces ethylene oxide, and keeps the temperature at 60-70°C for 2-4 hours, then cools the temperature to 40-50°C.
[0028] As a further improvement of the above solution, the mixed catalyst accounts for 0.5% to 1% of the pentaerythritol.
[0029] As a further improvement of the above solution, the mixed monomer includes propylene oxide and ethylene oxide, wherein the ratio of propylene oxide to ethylene oxide is 3:1.
[0030] As a further improvement to the above scheme, during the reaction of a mixed monomer of propylene oxide and ethylene oxide, the molecular weight growth trend is monitored in real time by infrared spectroscopy. In the present invention, chain growth is achieved by introducing a mixed monomer, increasing the molecular weight of the polyether to 5,000 to 10,000. When the molecular weight of the synthesized polyether is increased to 5,000 to 10,000, the product exhibits a higher viscosity.
[0031] As a further improvement to the above solution, the functional monomer is an unsaturated alcohol or an aromatic monomer. In the present invention, the functional monomer is used to modify the polyether chain end with a hydroxyl group, thereby optimizing the polyether polymer chain end structure and improving the thermal stability and weather resistance of the polyether product.
[0032] As a further improvement of the above scheme, the method of introducing functional monomers to modify the properties of the polyether chain ends is specifically performed as follows:
[0033] S41: Add phthalic anhydride to the reactor, raise the temperature to 80-90°C, stabilize the pressure at 2 MPa, and keep the reaction at this temperature for 6 hours;
[0034] S42 is cooled to 40-50°C, filtered, discharged and measured to obtain high-viscosity polyether.
[0035] Compared with the prior art, the present invention has the following beneficial effects:
[0036] The method of the present invention can synthesize a polyether product having ultra-high viscosity, stable and reliable performance, and excellent thermal stability through three stages of polyol initiation, chain growth, and polymer chain end modification. The polyether product has excellent application prospects in high-viscosity lubricants, high-strength adhesives, and high-temperature sealing materials.
[0037] The method of the present invention uses a solvent-free reaction throughout the polyether synthesis process and is combined with a low-toxic ternary mixed catalytic system, thereby reducing environmental pollution and conforming to the important trend of green chemical industry and high-efficiency material development.
[0038] The method of the present invention solves the problems of the prior art such as the difficulty in simultaneously increasing the molecular weight and viscosity of polyethers, insufficient catalyst activity, and environmental protection through a three-stage modular reaction design, a unique ternary mixed catalytic system, and precise temperature control at each stage. The obtained polyether product has significantly better performance than the prior art and is suitable for high-end industrial applications. BRIEF DESCRIPTION OF THE DRAWINGS
[0039] Figure 1 Shown is a flow chart of a method for synthesizing high-viscosity polyether using a polyol composite catalysis provided by the present invention. DETAILED DESCRIPTION
[0040] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the embodiments. Additional aspects and advantages of the present invention will be partially given in the following description, partially become apparent from the following description, or be understood through practice of the present invention. It should be understood that the following description is only intended to explain the present invention and is not intended to limit the present invention.
[0041] As used herein, the terms "comprises," "includes," "contains," or any other variations thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.
[0042] When amount, concentration or other value or parameter is expressed as range, preferred range, or a series of upper preferred values and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, regardless of whether the range is disclosed separately. For example, when disclosing a range of "1 to 5", the described range should be interpreted as including ranges of "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5" etc. When a numerical range is described in this article, unless otherwise stated, the range is intended to include its end values and all integers and fractions within the range.
[0043] The specific embodiments of the present invention are described in detail below.
[0044] Example 1
[0045] This embodiment provides a method for synthesizing high-viscosity polyether using a polyol composite catalysis, which comprises the following steps:
[0046] S1 prepares the mixed catalyst and sets aside.
[0047] The mixed catalyst is composed of a cobalt-zinc catalyst, a 1-methylimidazole catalyst and nano-graphene oxide. The method for preparing the mixed catalyst is specifically performed as follows:
[0048] S11: Add 50 kg of cobalt salt, 116 kg of zinc salt, 10 kg of nano-graphene oxide and 600 kg of methanol into a dry and clean reactor and stir until the mixture is uniform.
[0049] S12: 3 kg of 1-methylimidazole and 50 kg of methanol are pumped into a dropping tank and stirred to obtain a 1-methylimidazole / methanol solution. It should be noted that in actual synthesis, the balance between catalytic activity and selectivity can be achieved by adjusting the amount of 1-methylimidazole added, which will not be described in detail here.
[0050] In step S13, the temperature in the reactor was controlled to be less than 50°C, and the 1-methylimidazole / methanol solution was slowly added dropwise to the reactor and stirred for 30 minutes.
[0051] S14 continues to pump 5kg of triethanolamine into the dropping tank, and then drops it into the reactor.
[0052] After the addition of S15 was completed, the ultrasonic frequency was set to 30 kHz and the stirring time was 120 min.
[0053] S16 is subjected to cooling, filtering, and drying to obtain a mixed catalyst consisting of a cobalt-zinc catalyst, a 1-methylimidazole catalyst, and nano-graphene oxide;
[0054] In the mixed catalyst of this embodiment, the chemical formula of the cobalt-zinc catalyst is Zn3[Co(CN)6]2·xH2O, which has excellent low-temperature activity and can catalyze polymerization reactions at lower temperatures, thereby reducing the energy consumption of the synthesis process. In addition, the cobalt-zinc catalyst is a complex with a crystal size controlled at 10 to 30 nm, good activity and stability, and overcomes the problem of metal residue.
[0055] In this example, a synergistic catalytic system was established with a cobalt-zinc catalyst as the main catalyst, an organic imidazole catalyst as the cocatalyst, and nanographene as a dispersing aid to improve the efficiency of polyether synthesis. The bimetallic catalyst was surface-modified with a low-toxic organic amine, further enhancing its initiation ability for polyols. The organic imidazole catalyst also improved the ring-opening efficiency of epoxide monomers (propylene oxide and ethylene oxide) during the synthesis of polyethers. Furthermore, nanographene oxide has high thermal conductivity and a two-dimensional structure composed of a single layer of carbon atoms. Its surface is rich in oxygen-containing functional groups such as hydroxyl and carboxyl groups, which can improve the dispersion of the catalyst in the polyol matrix, thereby reducing local overheating and, in turn, the occurrence of side reactions such as cross-linking and chain scission.
[0056] S2 uses glycerol as an initiator, which reacts with ethylene oxide under the action of a mixed catalyst system to produce an initial low molecular weight polyether. In this embodiment, glycerol, a triol, is used as an initiator to increase the initial viscosity of the polyether molecular chain.
[0057] The method for generating the initial low molecular weight polyether is specifically performed as follows:
[0058] S21: Add 100 kg of glycerol and 0.5 kg of mixed catalyst into a dry and clean reactor, heat to 60°C, and stir for 30 minutes.
[0059] S22 controls the reaction temperature to 60°C and the pressure to 2MPa, slowly introduces ethylene oxide, and keeps the temperature at 70°C for 4h. At this time, a low molecular weight polyether (Mw=500-2000) is synthesized, and then the temperature is lowered to 50°C.
[0060] S3 continues to introduce 4700kg of propylene oxide and ethylene oxide mixed monomers for reaction until the molecular weight of the polyether increases to 5000-10000. In the mixed monomers, the ratio of propylene oxide to ethylene oxide is 3:1. During the process of introducing the propylene oxide and ethylene oxide mixed monomers for reaction, the molecular weight growth trend is monitored in real time by infrared spectroscopy.
[0061] In this embodiment, chain growth is achieved by introducing a mixed monomer, increasing the molecular weight of the polyether to 5,000 to 10,000. When the molecular weight of the synthesized polyether is increased to 5,000 to 10,000, the product exhibits a relatively high viscosity. In actual operation, the amount of the mixed catalyst added can be adjusted, such as by using an automated catalyst to replenish the catalyst, to maintain continuous and stable catalyst activity during the reaction. The specific adjustment process is not detailed here. The amount of the mixed catalyst added is not greater than 5% by weight of the total reactants.
[0062] S4 introduces phthalic anhydride to modify the properties of the polyether chain ends to synthesize a high-viscosity polyether. In this embodiment, phthalic anhydride, a functional monomer, is used to modify the polyether chain ends with hydroxyl groups, thereby optimizing the structure of the polyether polymer chain ends and thereby improving the thermal stability and weather resistance of the polyether product. The method of introducing a functional monomer to modify the properties of the polyether chain ends is specifically performed as follows:
[0063] S41 Add 160 kg of phthalic anhydride into the reactor, raise the temperature to 90 ° C, stabilize the pressure at 2 MPa, and keep the reaction at this temperature for 6 hours.
[0064] S42 is cooled to 50°C, filtered, discharged and metered to obtain high-viscosity polyether.
[0065] In summary, the method of this embodiment, through the three stages of polyol initiation, chain growth and polymer chain end modification, can synthesize a polyether product with ultra-high viscosity performance, stable and reliable performance, and excellent thermal stability, which has excellent application prospects in high-viscosity lubricants, high-strength adhesives and high-temperature sealing materials. In addition, the polyether synthesis process is a solvent-free reaction, and the low-toxic ternary mixed catalytic system is used to reduce environmental pollution, which is in line with the important trend of green chemical industry and high-efficiency material development. Through the three-stage modular reaction design, the unique ternary mixed catalytic system and the precise temperature control of each stage, the core bottleneck of the preparation of ultra-high viscosity polyether is solved, and the obtained product performance is significantly better than that of the prior art, which is suitable for high-end industrial applications.
[0066] Example 2
[0067] This embodiment provides a method for synthesizing high-viscosity polyether using a polyol composite catalysis, which comprises the following steps:
[0068] S1 prepares the mixed catalyst and sets aside.
[0069] The mixed catalyst is composed of a cobalt-zinc catalyst, a 1-methylimidazole catalyst and nano-graphene oxide. The method for preparing the mixed catalyst is specifically performed as follows:
[0070] S11: Add 50 kg of cobalt salt, 120 kg of zinc salt, 10 kg of nano-graphene oxide and 550 kg of methanol into a dry and clean reactor and stir until the mixture is uniform.
[0071] S12: 3 kg of 1-methylimidazole and 45 kg of methanol are pumped into a dropping tank and stirred to obtain a 1-methylimidazole / methanol solution. It should be noted that in actual synthesis, the balance between catalytic activity and selectivity can be achieved by adjusting the amount of 1-methylimidazole added, which will not be described in detail here.
[0072] In step S13, the temperature in the reactor was controlled to be less than 50°C, and the 1-methylimidazole / methanol solution was slowly added dropwise to the reactor and stirred for 30 minutes.
[0073] S14 continues to pump 7kg of triethanolamine into the dropping tank, and then drops it into the reactor.
[0074] After the addition of S15 was completed, the ultrasonic frequency was set to 30 kHz and the stirring time was 120 min.
[0075] S16 is subjected to cooling, filtering, and drying treatments to obtain a mixed catalyst consisting of a cobalt-zinc catalyst, a 1-methylimidazole catalyst, and nano-graphene oxide.
[0076] S2 uses glycerol as an initiator, which reacts with ethylene oxide under the action of a mixed catalyst system to produce an initial low molecular weight polyether. In this embodiment, glycerol, a triol, is used as an initiator to increase the initial viscosity of the polyether molecular chain.
[0077] The method for generating the initial low molecular weight polyether is specifically performed as follows:
[0078] S21: Add 100 kg of glycerol and 1 kg of mixed catalyst into a dry and clean reactor, heat to 65°C, and stir for 30 minutes.
[0079] S22 controls the reaction temperature to 65°C and the pressure to 1.5 MPa, slowly introduces ethylene oxide, and keeps the temperature at 65°C for 3 hours. At this time, a low molecular weight polyether (Mw = 500-2000) is synthesized, and then the temperature is lowered to 45°C.
[0080] S3 continues to introduce 4500kg of propylene oxide and ethylene oxide mixed monomers for reaction until the molecular weight of the polyether increases to 5000-10000. In the mixed monomers, the ratio of propylene oxide to ethylene oxide is 3:1. During the process of introducing the propylene oxide and ethylene oxide mixed monomers for reaction, the molecular weight growth trend is monitored in real time by infrared spectroscopy.
[0081] S4: Add 150 kg of phthalic anhydride into the reactor, raise the temperature to 85°C, stabilize the pressure at 2 MPa, keep the temperature and react for 6 hours, then cool to 45°C, filter, discharge and measure to obtain high-viscosity polyether.
[0082] In summary, the method of this embodiment, through the three stages of polyol initiation, chain growth and polymer chain end modification, can synthesize a polyether product with ultra-high viscosity performance, stable and reliable performance, and excellent thermal stability, which has excellent application prospects in high-viscosity lubricants, high-strength adhesives and high-temperature sealing materials. In addition, the polyether synthesis process is a solvent-free reaction, and the low-toxic ternary mixed catalytic system is used to reduce environmental pollution, which is in line with the important trend of green chemical industry and high-efficiency material development. Through the three-stage modular reaction design, the unique ternary mixed catalytic system and the precise temperature control of each stage, the core bottleneck of the preparation of ultra-high viscosity polyether is solved, and the obtained product performance is significantly better than that of the prior art, which is suitable for high-end industrial applications.
[0083] Example 3
[0084] This embodiment provides a method for synthesizing high-viscosity polyether using a polyol composite catalysis, which comprises the following steps:
[0085] S1 prepares the mixed catalyst and sets aside.
[0086] The mixed catalyst is composed of a cobalt-zinc catalyst, a 1-methylimidazole catalyst and nano-graphene oxide. The method for preparing the mixed catalyst is specifically performed as follows:
[0087] S11: Add 50 kg of cobalt salt, 120 kg of zinc salt, 10 kg of nano-graphene oxide and 550 kg of methanol into a dry and clean reactor and stir until the mixture is uniform.
[0088] S12: 3 kg of 1-methylimidazole and 45 kg of methanol are pumped into a dropping tank and stirred to obtain a 1-methylimidazole / methanol solution. It should be noted that in actual synthesis, the balance between catalytic activity and selectivity can be achieved by adjusting the amount of 1-methylimidazole added, which will not be described in detail here.
[0089] In step S13, the temperature in the reactor was controlled to be less than 50°C, and the 1-methylimidazole / methanol solution was slowly added dropwise to the reactor and stirred for 30 minutes.
[0090] S14 continues to pump 7kg of triethanolamine into the dropping tank, and then drops it into the reactor.
[0091] After the addition of S15 was completed, the ultrasonic frequency was set to 30 kHz and the stirring time was 120 min.
[0092] S16 is subjected to cooling, filtering, and drying treatments to obtain a mixed catalyst consisting of a cobalt-zinc catalyst, a 1-methylimidazole catalyst, and nano-graphene oxide.
[0093] S2 uses pentaerythritol as an initiator, which reacts with ethylene oxide under the action of a mixed catalyst system to generate an initial low molecular weight polyether.
[0094] The method for generating the initial low molecular weight polyether is specifically performed as follows:
[0095] S21: Add 100 kg of pentaerythritol and 0.5 kg of mixed catalyst into a dry and clean reactor, heat to 65°C, and stir for 30 minutes.
[0096] S22 controls the reaction temperature to 65°C and the pressure to 1.5 MPa, slowly introduces ethylene oxide, and keeps the temperature at 65°C for 3 hours. At this time, a low molecular weight polyether (Mw = 500-2000) is synthesized, and then the temperature is lowered to 45°C.
[0097] S3 continues to introduce 4500kg of propylene oxide and ethylene oxide mixed monomers for reaction until the molecular weight of the polyether increases to 5000-10000. In the mixed monomers, the ratio of propylene oxide to ethylene oxide is 3:1. During the process of introducing the propylene oxide and ethylene oxide mixed monomers for reaction, the molecular weight growth trend is monitored in real time by infrared spectroscopy.
[0098] In step S4, 150 kg of propylene glycol was added to the reactor, the temperature was raised to 85°C, the pressure was stabilized at 2 MPa, the reaction was maintained at this temperature for 6 hours, and the temperature was lowered to 45°C. After filtering, the material was discharged, and the material was metered to obtain a high-viscosity polyether. In this embodiment, propylene glycol, a functional monomer, was used to modify the polyether chain ends with hydroxyl groups, thereby optimizing the terminal structure of the polyether polymer chain and improving the thermal stability and weather resistance of the polyether product.
[0099] In summary, the method of this embodiment, through the three stages of polyol initiation, chain growth and polymer chain end modification, can synthesize a polyether product with ultra-high viscosity performance, stable and reliable performance, and excellent thermal stability, which has excellent application prospects in high-viscosity lubricants, high-strength adhesives and high-temperature sealing materials. In addition, the polyether synthesis process is a solvent-free reaction, and the low-toxic ternary mixed catalytic system is used to reduce environmental pollution, which is in line with the important trend of green chemical industry and high-efficiency material development. Through the three-stage modular reaction design, the unique ternary mixed catalytic system and the precise temperature control of each stage, the core bottleneck of the preparation of ultra-high viscosity polyether is solved, and the obtained product performance is significantly better than that of the prior art, which is suitable for high-end industrial applications.
[0100] Example 4
[0101] This embodiment provides a method for synthesizing high-viscosity polyether using a polyol composite catalysis, which comprises the following steps:
[0102] S1 prepares the mixed catalyst and sets aside.
[0103] The mixed catalyst is composed of a cobalt-zinc catalyst, a 1-methylimidazole catalyst and nano-graphene oxide. The method for preparing the mixed catalyst is specifically performed as follows:
[0104] S11: Add 50 kg of cobalt salt, 116 kg of zinc salt, 10 kg of nano-graphene oxide and 600 kg of methanol into a dry and clean reactor and stir until the mixture is uniform.
[0105] S12: 3 kg of 1-methylimidazole and 50 kg of methanol are pumped into a dropping tank and stirred to obtain a 1-methylimidazole / methanol solution. It should be noted that in actual synthesis, the balance between catalytic activity and selectivity can be achieved by adjusting the amount of 1-methylimidazole added, which will not be described in detail here.
[0106] In step S13, the temperature in the reactor was controlled to be less than 50°C, and the 1-methylimidazole / methanol solution was slowly added dropwise to the reactor and stirred for 30 minutes.
[0107] S14 continues to pump 5kg of triethanolamine into the dropping tank, and then drops it into the reactor.
[0108] After the addition of S15 was completed, the ultrasonic frequency was set to 30 kHz and the stirring time was 120 min.
[0109] S16 is subjected to cooling, filtering, and drying treatments to obtain a mixed catalyst consisting of a cobalt-zinc catalyst, a 1-methylimidazole catalyst, and nano-graphene oxide.
[0110] S2 uses pentaerythritol as an initiator to react with ethylene oxide under the action of a mixed catalyst system to produce an initial low molecular weight polyether. In this embodiment, pentaerythritol, a tetrahydric alcohol, is used as an initiator to increase the initial viscosity of the polyether molecular chain.
[0111] The method for generating the initial low molecular weight polyether is specifically performed as follows:
[0112] S21: Add 100 kg of pentaerythritol and 0.5 kg of mixed catalyst into a dry and clean reactor, heat to 70°C, and stir for 30 minutes.
[0113] S22 controls the reaction temperature to 70°C and the pressure to 2MPa, slowly introduces ethylene oxide, and keeps the temperature at 70°C for 4h. At this time, a low molecular weight polyether (Mw=500-2000) is synthesized, and then the temperature is lowered to 50°C.
[0114] S3 continues to introduce 4700kg of propylene oxide and ethylene oxide mixed monomers for reaction until the molecular weight of the polyether increases to 5000-10000. In the mixed monomers, the ratio of propylene oxide to ethylene oxide is 3:1. During the process of introducing the propylene oxide and ethylene oxide mixed monomers for reaction, the molecular weight growth trend is monitored in real time by infrared spectroscopy.
[0115] S4: Add 150kg of propylene alcohol into the reactor, raise the temperature to 90℃, stabilize the pressure at 2MPa, keep the temperature and react for 6h, then cool to 50℃, filter, discharge and measure to obtain high-viscosity polyether.
[0116] In summary, the method of this embodiment, through the three stages of polyol initiation, chain growth and polymer chain end modification, can synthesize a polyether product with ultra-high viscosity performance, stable and reliable performance, and excellent thermal stability, which has excellent application prospects in high-viscosity lubricants, high-strength adhesives and high-temperature sealing materials. In addition, the polyether synthesis process is a solvent-free reaction, and the low-toxic ternary mixed catalytic system is used to reduce environmental pollution, which is in line with the important trend of green chemical industry and high-efficiency material development. Through the three-stage modular reaction design, the unique ternary mixed catalytic system and the precise temperature control of each stage, the core bottleneck of the preparation of ultra-high viscosity polyether is solved, and the obtained product performance is significantly better than that of the prior art, which is suitable for high-end industrial applications.
[0117] The following is a performance test of the polyether product synthesized by the method of Examples 1-4. The test process is not described in detail here. The test structure is as follows:
[0118] Viscosity tests showed that the viscosities of the polyether products of Examples 1-4 were all above 10,000 cP, demonstrating that the method of the present invention can produce polyether products with ultra-high viscosity performance. The produced polyethers have excellent application prospects in high-viscosity lubricants and high-strength adhesives.
[0119] The narrow molecular weight distribution test showed that the polyether products of Examples 1-4 had a PDI of <1.3, indicating a narrow molecular weight distribution range. Studies have shown that polymer materials with a narrow molecular weight distribution range have a more uniform molecular structure, resulting in more stable product performance and better reliability. During processing, properties such as melt viscosity, thermal stability, and rheological properties are also more uniform. This demonstrates that the method of the present invention can produce polyether products with stable performance.
[0120] Thermal stability test: After testing, the polyether products of Examples 1-4 showed no obvious degradation at 200-250°C, which proves that the polyether prepared by the method of the present invention has excellent thermal stability, can meet the use requirements under high temperature conditions, and has excellent application prospects in high-temperature sealing materials.
[0121] The above embodiments are merely preferred implementations of the present invention. Any simple modifications, amendments, and substitutions made to the above embodiments based on the technical essence of the present invention fall within the scope of the technical solution of the present invention.
Claims
1. A method for synthesizing high-viscosity polyether by composite catalysis of polyols, characterized in that: The following steps are involved: S1 prepares a mixed catalyst for standby use; The mixed catalyst is composed of a bimetallic catalyst, an organic imidazole catalyst and nano-graphene oxide; S2 uses polyol as an initiator and reacts with ethylene oxide under the action of a mixed catalyst system to produce an initial low molecular weight polyether; S3 continues to introduce mixed monomers to react until the molecular weight of the polyether increases to 5000-10000; S4 introduces functional monomers to modify the properties of the polyether chain ends to synthesize high-viscosity polyether.
2. The method for synthesizing high-viscosity polyether by composite catalysis of polyols according to claim 1, characterized in that: The method for preparing the mixed catalyst is specifically performed as follows: S11 adds cobalt salt, zinc salt, nano-graphene oxide and methanol into a dry and clean reactor and stirs until the state is uniform; S12: 1-methylimidazole and methanol are pumped into a dropping tank and stirred to obtain a 1-methylimidazole / methanol solution; S13: Control the temperature in the reactor to <50°C, slowly add 1-methylimidazole / methanol solution dropwise to the reactor, and stir for 30 minutes; S14 continues to pump triethanolamine into the dropping tank, and then drops it into the reactor; After the addition of S15 was completed, the ultrasonic frequency was set to 30 kHz and the stirring time was 120 min; S16 is subjected to cooling, filtering and drying to obtain a mixed catalyst.
3. The method for synthesizing high-viscosity polyether by composite catalysis of polyols according to claim 2, characterized in that: The weight ratio of the cobalt salt, zinc salt, nano graphite oxide and methanol is 4-6:10-15:1:50-70; The weight ratio of the 1-methylimidazole to methanol is 1:15-20.
4. The method for synthesizing high-viscosity polyether by composite catalysis of polyols according to claim 3, characterized in that: After cooling, filtering and drying, a mixed catalyst consisting of a cobalt-zinc bimetallic catalyst, a 1-methylimidazole catalyst and nano-graphene oxide is obtained.
5. The method for synthesizing high-viscosity polyether by composite catalysis of polyols according to claim 1, characterized in that: The polyol is glycerol or pentaerythritol; The method for generating the initial low molecular weight polyether is specifically performed as follows: S21 Add pentaerythritol and mixed catalyst into a dry and clean reactor, heat to 60-70°C, and stir for 30 minutes; S22 controls the reaction temperature to 60-70°C and the pressure to 1-2 MPa, slowly introduces ethylene oxide, and keeps the temperature at 60-70°C for 2-4 hours, then cools the temperature to 40-50°C.
6. The method for synthesizing high-viscosity polyether using a polyol composite catalyst according to claim 5, characterized in that: The mixed catalyst accounts for 0.5% to 1% of pentaerythritol.
7. The method for synthesizing high-viscosity polyether by composite catalysis of polyols according to claim 1, characterized in that: The mixed monomers include propylene oxide and ethylene oxide, wherein the ratio of propylene oxide to ethylene oxide is 3:
1.
8. The method for synthesizing high-viscosity polyether using a polyol composite catalyst according to claim 7, wherein: During the reaction of the mixed monomers of propylene oxide and ethylene oxide, the molecular weight growth trend was monitored in real time by infrared spectroscopy.
9. The method for synthesizing high-viscosity polyether using a polyol composite catalyst according to claim 1, wherein: The functional monomer is an unsaturated alcohol or an aromatic monomer.
10. The method for synthesizing high-viscosity polyether using a polyol composite catalyst according to claim 9, characterized in that: The method of introducing functional monomers to modify the terminal properties of the polyether chain is specifically performed as follows: S41: Add phthalic anhydride to the reactor, raise the temperature to 80-90°C, stabilize the pressure at 2 MPa, and keep the reaction at this temperature for 6 hours; S42 is cooled to 40-50°C, filtered, discharged and measured to obtain high-viscosity polyether.