阅读说明：本技术 一种聚四氢呋喃聚环氧丙烷嵌段共聚醚的制备方法 (Preparation method of polytetrahydrofuran polypropylene oxide block copolyether ) 是由 郝敬颖 杨雨强 朱姝 关淞云 于 2021-09-30 设计创作，主要内容包括：本发明涉及一种聚四氢呋喃聚环氧丙烷嵌段共聚醚的制备方法,将DMC或MMC催化剂均匀分散于溶剂中形成分散体系；将该分散体系、平均数均分子量为180～2000的聚四氢呋喃投入反应釜混合,将釜温升至120～140℃,预投环氧化合物引发反应,待反应引发后再连续投入环氧化合物,使产品分子量为500-3000结束反应,得到DMC或MMC预聚物；将平均数均分子量为180～2000的聚四氢呋喃和DMC或MMC预聚物投入反应釜中,将釜温升至120～140℃,预投环氧化合物引发反应,待反应引发后再连续投入环氧化合物,使产物分子量为1000-12000结束反应,减压脱除未反应环氧化合物和溶剂得到目标产物。(The invention relates to a preparation method of polytetrahydrofuran polypropylene oxide block copolyether, which is characterized in that DMC or MMC catalyst is uniformly dispersed in a solvent to form a dispersion system; putting the dispersion system and polytetrahydrofuran with the average molecular weight of 180-2000 into a reaction kettle for mixing, raising the temperature of the kettle to 120-140 ℃, pre-putting an epoxy compound for initiating reaction, continuously putting the epoxy compound after the reaction is initiated, and ending the reaction until the molecular weight of the product is 500-3000 to obtain a DMC or MMC prepolymer; putting polytetrahydrofuran with average number average molecular weight of 180-2000 and DMC or MMC prepolymer into a reaction kettle, raising the temperature of the kettle to 120-140 ℃, pre-adding epoxy compound to initiate reaction, continuously adding epoxy compound after the reaction is initiated to ensure that the molecular weight of the product is 1000-12000, finishing the reaction, and removing unreacted epoxy compound and solvent under reduced pressure to obtain the target product.)

1. A preparation method of polytetrahydrofuran polypropylene oxide block copolyether is characterized by comprising the following steps:

1) uniformly dispersing the synthesized polyether in a solvent by using a bimetallic or multi-metal catalyst (DMC or MMC) according to the calculated amount to obtain a dispersion system;

2) putting the dispersion system obtained in the step 1) and polytetrahydrofuran with the average number average molecular weight of 180-2000 into a reaction kettle, uniformly mixing, raising the temperature of the kettle to 120-140 ℃, pre-adding an epoxy compound to initiate reaction, continuously adding the epoxy compound after the reaction is initiated, and finishing the reaction to obtain a DMC or MMC prepolymer, wherein the molecular weight of the product is 500-3000;

3) putting polytetrahydrofuran with the average number average molecular weight of 180-2000 and the prepolymer obtained in the step 2) into a reaction kettle, uniformly mixing, heating the kettle to 120-140 ℃, adding an epoxy compound in advance to initiate a reaction, continuously adding the epoxy compound after the reaction is initiated to enable the molecular weight of the product to be 1000-12000, finishing the reaction, and removing the unreacted epoxy compound and the solvent under reduced pressure to obtain the target product.

2. The preparation method according to claim 1, wherein the solvent in step 1) is one or more of ethanol, isopropanol, diethyl ether or tert-butanol.

3. The method according to claim 1, wherein the solvent is used in an amount of 1/6 to 1/2 based on the total amount of polytetrahydrofuran.

4. The process of claim 1, wherein the DMC or MMC catalyst is used in an amount of 12X 10 by weight, based on the weight of the target product^－6～30×10^－6。

5. The process according to claim 1, wherein the epoxy compound is propylene oxide or a mixture of propylene oxide and ethylene oxide.

6. The method according to claim 1, wherein the amount of the epoxy compound to be added is 1/10 to 1/2 of the amount of the polytetrahydrofuran to be added in the reaction.

Technical Field

The invention relates to a preparation method of polytetrahydrofuran polypropylene oxide block copolyether.

Background

The hydroxyl-terminated polyether glycol is a main raw material for preparing the polyurethane elastomer, and a polyurethane product prepared from the polytetrahydrofuran ether glycol has better performance, particularly high hardness and good wear resistance. But is expensive, solid at normal temperature and inconvenient for post-processing. At present, tetrahydrofuran-propylene oxide (or ethylene oxide) random copolyether is commonly used at home and abroad as a raw material to prepare a polyurethane product, and the property and the excellent performance similar to those of the polyurethane product prepared by polytetrahydrofuran can be obtained. However, the preparation process of tetrahydrofuran-propylene oxide (or ethylene oxide) random copolyether is complex, a boron trifluoride-diethyl ether catalyst is generally used, the reaction is carried out in a low-temperature environment, the conversion rate is relatively low, post-treatment purification or rectification is required, the process is complex, and therefore, the cost is high. The polyether is basically used for military products, and cannot be popularized in civil markets all the time due to high price.

The polytetrahydrofuran polypropylene oxide block copolyether structure has introduced propylene oxide chain link, low cost, liquid state at normal temperature and easy post-processing operation. The polytetrahydrofuran-polypropylene oxide block copolyether synthesized by polymerizing propylene oxide with polytetrahydrofuran as a raw material has a relatively simple synthesis process and stable product quality. And the prepared polyurethane product also has the excellent performance similar to that of the polyurethane product prepared by random copolyether. At present, the block copolyethers have reports: such as CN1986599A and CN 101628975A. The catalyst is prepared by taking polytetrahydrofuran with different molecular weights as an initiator and propylene oxide (or a mixture of propylene oxide and ethylene oxide) as a chain extender and adopting a bimetallic or polymetallic catalyst (DMC or MMC) for catalytic synthesis. Compared with polytetrahydrofuran ether glycol and tetrahydrofuran-propylene oxide (or ethylene oxide) random copolyether, the cost of the product has the advantages of cost and better performance, but due to the defects of DMC or MMC catalyst, when lower molecular weight polytetrahydrofuran (the number average molecular weight is lower than 350) is adopted as a starter, the lower dosage of DMC or MMC catalyst can not catalyze the reaction of the low molecular weight polytetrahydrofuran and propylene oxide or ethylene oxide, the existing solution method can only increase the dosage of DMC or MMC catalyst to ensure the reaction to be smoothly carried out, and the dosage of DMC or MMC catalyst in the block copolyether product needs to reach 80 x 10^－6～150×10^－6Resulting in increased cost and adverse effects on subsequent article applications due to the presence of Co, Zn, Pb, etc. components in the DMC or MMC catalyst component, if not removed.

We have found in their research that the use of solvent prepolymerization allows lower molecular weight polytetrahydrofuran to be polymerized with propylene oxide or ethylene oxide in the presence of lower amounts of DMC or MMC catalysts to form polytetrahydrofuran propylene oxide block copolyethers. The amount of metal ions introduced into the final product is low enough not to affect the subsequent application, and the step of removing the catalyst can be omitted.

Disclosure of Invention

Aiming at the problems and the defects in the prior art, the research finds that the method adopting the solvent prepolymerization can solve the problem that the low molecular weight polytetrahydrofuran can not successfully react with propylene oxide or ethylene oxide in the presence of a DMC or MMC catalyst with low dosage. The amount of catalyst used is also only 12X 10 based on the weight of the target product^－6～30×10^－6And the metal ions contained in the product are low in quantity and do not need to be removed.

The invention aims to provide a preparation method of polytetrahydrofuran polypropylene oxide block copolyether, which comprises the following specific steps:

1) uniformly dispersing the DMC or MMC catalyst in a solvent consisting of one or a mixture of ethanol, isopropanol, ether or tert-butanol to obtain a dispersion system;

2) putting the dispersion system obtained in the step 1) and polytetrahydrofuran with the average number average molecular weight of 180-2000 into a reaction kettle, uniformly mixing, raising the temperature of the kettle to 120-140 ℃, pre-adding an epoxy compound to initiate reaction, continuously adding the epoxy compound after the reaction is initiated, and finishing the reaction to obtain a DMC or MMC prepolymer, wherein the molecular weight of the product is 500-3000;

3) putting polytetrahydrofuran with the average number average molecular weight of 180-2000 and the prepolymer obtained in the step 2) into a reaction kettle, uniformly mixing, heating the kettle to 120-140 ℃, adding an epoxy compound in advance to initiate a reaction, continuously adding the epoxy compound after the reaction is initiated to enable the molecular weight of the product to be 1000-12000, finishing the reaction, and removing the unreacted epoxy compound and the solvent under reduced pressure to obtain the target product.

The DMC or MMC catalyst is used in an amount of 12X 10 based on the weight of the target product^－6～30×10^－6。

The epoxy compound is propylene oxide or a mixture of propylene oxide and ethylene oxide.

The dosage of the solvent is 1/6-1/2 of the total amount of the polytetrahydrofuran.

The amount of the epoxy compound to be added in advance is 1/10-1/2 of the amount of the polytetrahydrofuran to be added in the reaction.

The DMC or MMC catalyst is generally a powdery solid and is in a dispersion state in a polyether polyol synthesis reaction system, due to the existence of certain granularity, the DMC or MMC catalyst can firstly generate an effect on a contact surface layer in the catalysis process, and then the condition of permeation stripping layer by layer occurs, because polytetrahydrofuran has certain viscosity, the higher the molecular weight is, the larger the viscosity is (the higher the number average molecular weight reaches 700 or above, the normal temperature is in a solid state), the DMC (or MMC) catalyst can be directly dispersed in the polytetrahydrofuran, and the process of permeation stripping is slow, so that the DMC (or MMC) catalyst cannot fully exert the catalysis effect. The DMC (or MMC) catalyst is uniformly dispersed in the solvent by adopting solvent polymerization and selecting the solvent with excellent compatibility with polyether, and then is mixed with the polytetrahydrofuran, so that the DMC (or MMC) catalyst can be uniformly mixed with reactants better, the solvent has better compatibility with the polytetrahydrofuran, the viscosity of a system is reduced due to the low viscosity of the solvent, the layer-by-layer permeation and stripping process of the DMC (or MMC) catalyst is easy to occur, and the catalytic action of the catalyst is fully exerted. By adopting a prepolymerization method, polytetrahydrofuran with lower molecular weight is polymerized into a prepolymer with larger molecular weight (as a block copolyether intermediate product), and then the prepolymer is used as a catalyst for synthesizing a target product, so that the dosage of a DMC (or MMC) catalyst in the final target product is lower and is only 12 x 10 of the target product^－6～30×10^－6。

The invention adopts a solvent prepolymerization method, overcomes the technical problem that the conventional method which adopts low molecular weight polytetrahydrofuran with the number average molecular weight of less than 350 and propylene oxide or ethylene oxide can not smoothly react in the presence of a lower using amount of DMC or MMC catalyst, and the invention adopts a solvent prepolymerization method in the presence of a lower DMC or MMC catalyst (the amount of the DMC or MMC catalyst is 12 x 10 based on the weight of a target product)^－6～30×10^－6) The polytetrahydrofuran propylene oxide block copolyether is produced by polymerizing low molecular weight polytetrahydrofuran with number average molecular weight of less than 350 and propylene oxide or ethylene oxideThe metal ions introduced into the final polyether product are low in amount, so that the subsequent polyether application is not influenced, and the step of removing the catalyst can be omitted. The process can also be generalized to the polymerization of propylene oxide or ethylene oxide with other different molecular weight polytetrahydrofurans having a number average molecular weight equal to or higher than 350, as well as to the polymerization of propylene oxide or ethylene oxide with other low molecular weight or higher molecular weight starters for the synthesis of polyether polyol products.

Detailed Description

Uniformly dispersing the DMC or MMC catalyst in one or a mixture of ethanol, isopropanol, ether or tert-butanol to form a stable dispersion system; and putting the dispersion system and polytetrahydrofuran with the average number average molecular weight of 180-2000 into a reaction kettle, heating to 120-140 ℃, pre-putting a certain amount of epoxy compound for initiating reaction, and continuously putting the epoxy compound after the reaction is initiated to ensure that the average number average molecular weight of the product is 500-3000, and finishing the reaction to obtain the DMC prepolymer. The prepolymer is applied to the synthesis of block copolyether, and low molecular weight polytetrahydrofuran with the number average molecular weight of less than 350 is adopted to react with propylene oxide or ethylene oxide, the method comprises the steps of putting the obtained prepolymer and polytetrahydrofuran with the average number average molecular weight of 180-2000 into a reaction kettle, uniformly mixing, raising the temperature of the kettle to 120-140 ℃, pre-adding a certain amount of epoxy compound to initiate reaction, continuously adding the epoxy compound after the reaction is initiated, finishing the reaction when the molecular weight of the product is 1000 plus 12000, and removing unreacted epoxy compound and solvent under reduced pressure to obtain the target product. Using the above process, the amount of bimetallic or multimetal catalyst used in the final target product is only 12X 10 based on the weight of the target product^－6～30×10^－6And the metal ions contained in the product are low in quantity and do not need to be removed. Likewise, the process can also be used for the reaction of higher number average molecular weight polytetrahydrofuran having a number average molecular weight of 350 or more with propylene oxide or ethylene oxide, the amount of bimetallic or multimetal catalyst used in the final target product also being only 12X 10 based on the weight of the target product^－6～30×10^－6And the metal ions contained in the product are low in quantity and do not need to be removed.

Example 1

Mixing 0.04g of DMC catalyst and 100g of ethanol, putting into a reaction kettle, adding 200g of polytetrahydrofuran with the number average molecular weight of 250 uniformly, raising the temperature of the kettle to 130-140 ℃, keeping the temperature continuously, adding 20g of propylene oxide, recording a pressure curve, and continuously adding 580g of propylene oxide when the pressure is reduced to 0.05MPa to obtain a DMC prepolymer;

putting 200g of polytetrahydrofuran with the number average molecular weight of 250 and DMC prepolymer into a reaction kettle, uniformly mixing, heating the kettle to 130-140 ℃, continuously preserving heat, putting 40g of propylene oxide, recording a pressure curve, continuously putting 1000g of propylene oxide when the pressure is reduced to 0.05MPa, preserving heat for 1 hour, and removing unreacted propylene oxide and ethanol under reduced pressure to obtain the block copolyether glycol A with the average molecular weight of about 5100.

Example 2

Fully mixing 0.0216g of DMC catalyst and 90g of diethyl ether, putting into a reaction kettle, adding 180g of polytetrahydrofuran with the number average molecular weight of 200, uniformly mixing, heating the kettle to 120-130 ℃, continuously preserving the temperature, adding 90g of propylene oxide, recording a pressure curve, and continuously adding 200g of propylene oxide when the pressure is reduced to 0.08MPa to obtain a DMC prepolymer;

adding 180g of polytetrahydrofuran with the number average molecular weight of 200 and DMC prepolymer into a reaction kettle, uniformly mixing, heating the kettle to 120-130 ℃, continuously preserving the temperature, adding 40g of propylene oxide, recording a pressure curve, continuously adding 1100g of propylene oxide when the pressure is reduced to 0.08MPa, preserving the temperature for 1 hour, and removing unreacted propylene oxide and ether under reduced pressure to obtain the block copolyether glycol B with the average molecular weight of about 1000.

Example 3

Fully mixing 0.05g of MMC catalyst and 200g of tert-butyl alcohol, putting into a reaction kettle, adding 210g of polytetrahydrofuran with the number average molecular weight of 300, uniformly mixing, heating the kettle to 120-130 ℃, continuously preserving heat, adding 50g of propylene oxide, recording a pressure curve, and continuously adding 500g of propylene oxide when the pressure is reduced to 0.05MPa to obtain an MMC prepolymer;

adding 210g of polytetrahydrofuran with the number average molecular weight of 300 and MMC prepolymer into a reaction kettle, uniformly mixing, heating the kettle to 120-130 ℃, continuously preserving the temperature, adding 50g of propylene oxide, recording a pressure curve, continuously adding 1000g of propylene oxide when the pressure is reduced to 0.05MPa, preserving the temperature for 1 hour, and removing unreacted propylene oxide and ether tert-butyl alcohol under reduced pressure to obtain the block copolyether glycol C with the average molecular weight of about 1450.

Example 4

Uniformly mixing propylene oxide and ethylene oxide according to a weight ratio of 3/1, fully mixing 0.145g of MMC catalyst with 120g of isopropanol, putting the mixture into a reaction kettle, adding 350g of polytetrahydrofuran with a number average molecular weight of 350, uniformly mixing, raising the temperature of the kettle to 130-140 ℃, continuously preserving the temperature, adding 50g of the mixture of the propylene oxide and the ethylene oxide which are uniformly mixed in advance into the reaction kettle, recording a pressure curve, and continuously adding 1100g of the mixture of the propylene oxide and the ethylene oxide which are uniformly mixed in advance when the pressure is reduced to 0.07MPa to obtain an MMC prepolymer;

adding 70g of polytetrahydrofuran and MMC prepolymer with the number average molecular weight of 350 into a reaction kettle, uniformly mixing, heating the kettle to 130-140 ℃, continuously preserving heat, adding 30g of uniformly mixed propylene oxide and ethylene oxide mixture, recording a pressure curve, continuously adding 7900g of uniformly mixed propylene oxide and ethylene oxide mixture when the pressure is reduced to 0.07MPa, preserving heat for 1 hour, and removing unreacted propylene oxide, ethylene oxide and isopropanol under reduced pressure to obtain the block copolyether glycol D with the average molecular weight of about 8000.

Example 5

Fully mixing 0.54g of DMC catalyst, 70g of tert-butyl alcohol and 70g of isopropanol, putting into a reaction kettle, adding 200g of polytetrahydrofuran with the number average molecular weight of 180, uniformly mixing, raising the temperature of the kettle to 130-140 ℃, continuously preserving the temperature, adding 100g of propylene oxide, recording a pressure curve, and continuously adding 1922g of propylene oxide when the pressure is reduced to 0.05MPa to obtain a DMC prepolymer;

adding 70g of polytetrahydrofuran with the number average molecular weight of 180 and DMC prepolymer into a reaction kettle, uniformly mixing, heating the kettle to 130-140 ℃, continuously preserving the temperature, adding 35g of propylene oxide, recording a pressure curve, continuously adding 15508g of propylene oxide when the pressure is reduced to 0.05MPa, preserving the temperature for 1 hour, and removing unreacted propylene oxide, tert-butyl alcohol and isopropanol under reduced pressure to obtain the block copolyether glycol E with the average molecular weight of about 12000.

Example 6

Fully mixing 0.0128g of DMC catalyst, 70g of tertiary butanol and 50g of ethanol, putting the mixture into a reaction kettle, adding 200g of polytetrahydrofuran with the number average molecular weight of 1000, uniformly mixing, raising the temperature of the kettle to 130-140 ℃, continuously preserving the temperature, adding 100g of propylene oxide, recording a pressure curve, and continuously adding 100g of propylene oxide when the pressure is reduced to 0.05MPa to obtain a DMC prepolymer;

putting 200g of polytetrahydrofuran with the number average molecular weight of 1000 and DMC prepolymer into a reaction kettle, uniformly mixing, heating the kettle to 130-140 ℃, continuously preserving the temperature, putting 100g of propylene oxide, recording a pressure curve, continuously putting 100g of propylene oxide when the pressure is reduced to 0.05MPa, preserving the temperature for 1 hour, and removing unreacted propylene oxide, ether tert-butyl alcohol and ethanol under reduced pressure to obtain the block copolyether glycol F with the average molecular weight of about 2000.

Example 7

Fully mixing 0.0216g of DMC catalyst and 110g of tert-butyl alcohol, putting into a reaction kettle, adding 300g of polytetrahydrofuran with the number average molecular weight of 2000, uniformly mixing, heating the kettle to 130-140 ℃, continuously preserving the temperature, adding 100g of propylene oxide, recording a pressure curve, and continuously adding 200g of propylene oxide when the pressure is reduced to 0.05MPa to obtain a DMC prepolymer;

adding 300G of polytetrahydrofuran with the number average molecular weight of 2000 and DMC prepolymer into a reaction kettle, uniformly mixing, heating the kettle to 130-140 ℃, continuously preserving the temperature, adding 100G of propylene oxide, recording a pressure curve, continuously adding 200G of propylene oxide when the pressure is reduced to 0.05MPa, preserving the temperature for 1 hour, and removing unreacted propylene oxide and tert-butyl alcohol under reduced pressure to obtain the block copolyether glycol G with the average molecular weight of about 4000.

Example 8

Uniformly mixing propylene oxide and ethylene oxide according to a weight ratio of 1/2, fully mixing 0.036g of DMC catalyst and 100g of ethanol, putting into a reaction kettle, adding 300g of polytetrahydrofuran with a number average molecular weight of 650, uniformly mixing, heating the kettle to 130 ℃ and 140 ℃, continuously preserving heat, adding 100g of a mixture of the propylene oxide and the ethylene oxide which are uniformly mixed in advance, recording a pressure curve, and continuously adding 1084g of the mixture of the propylene oxide and the ethylene oxide which are uniformly mixed in advance when the pressure is reduced to 0.05MPa to obtain a DMC prepolymer;

adding 300g of polytetrahydrofuran with the number average molecular weight of 650 and DMC prepolymer into a reaction kettle, uniformly mixing, heating the kettle to 130-140 ℃, continuously preserving heat, adding 100g of uniformly mixed propylene oxide and ethylene oxide mixture, recording a pressure curve, continuously adding 984g of uniformly mixed propylene oxide and ethylene oxide mixture when the pressure is reduced to 0.05MPa, preserving heat for 1 hour, and removing unreacted propylene oxide, ethylene oxide and ethanol under reduced pressure to obtain block copolyether glycol H with the average molecular weight of about 3000.

TABLE 1 attached hereto

Polyether polyols	Hydroxyl value (mgKOH/g)	DMC quantity (calculated as polyether polyol)
			A	22.12	19.61×10－6
B	112.04	12×10－6
			C	77.73	24.75×10－6
D	14.05	15.1×10－6
			E	9.36	30×10－6
F	55.96	16×10－6
			G	28.09	18×10－6
H	37.50	13×10－6

As can be seen from the table, the use of the process according to the invention makes it possible to obtain polytetrahydrofuran polypropylene oxide target products for polytetrahydrofuran synthesis in which the number-average molecular weight is less than or equal to 350 in which the DMC (or MMC) catalyst is used in a relatively low amount, 12X 10 based on the weight of the target product^－6～30×10^－6. Polytetrahydrofuran having a number average molecular weight of more than 350 can also be synthesized in this way, with the DMC (or MMC) catalyst being used in a lower amount in the target product.

The examples listed in the invention only take the synthesis reaction of polytetrahydrofuran and propylene oxide or ethylene oxide as an example, but are not limited to polytetrahydrofuran, and other low molecular weight (or higher molecular weight) compounds containing active hydrogen can be used for preparing the corresponding polyether polyol products by using the preparation method of the invention.

While the methods and techniques of the present invention have been described in terms of preferred embodiments, it will be apparent to those of ordinary skill in the art that variations and/or modifications of the methods and techniques described herein may be made without departing from the spirit and scope of the invention. It is expressly intended that all such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope and content of the invention. The invention belongs to the known technology.