阅读说明：本技术 低不饱和度高活性聚醚多元醇的制备方法 (Preparation method of polyether polyol with low unsaturation degree and high activity ) 是由 王腾 孙兆任 张德江 周玉波 李剑锋 于 2020-12-28 设计创作，主要内容包括：本发明属于聚醚多元醇合成技术领域,具体涉及一种低不饱和度高活性聚醚多元醇的制备方法。主要解决现有技术中使用氢氧化钾催化剂制备的高活性聚醚多元醇不饱和度较高、副反应多的问题。具体步骤为：第一步,用双金属氰化物络合物(DMC)催化剂催化低分子醇和环氧丙烷(PO)发生聚合反应生成中间物聚醚多元醇；第二步,向中间物聚醚多元醇中加入磷腈盐催化剂,通入环氧乙烷(EO)进行封端反应,所得产物用交换树脂和硅酸盐吸附剂处理即得到低不饱和度高活性聚醚多元醇。本发明制得的低不饱和度高活性聚醚多元醇具有不饱和度低、伯羟基含量高等优点,制备聚氨酯产品脱模时间短、物理机械性能好,适合用作汽车内饰等材料。(The invention belongs to the technical field of polyether polyol synthesis, and particularly relates to a preparation method of polyether polyol with low unsaturation degree and high activity. Mainly solves the problems of higher degree of unsaturation and more side reactions of high-activity polyether polyol prepared by using a potassium hydroxide catalyst in the prior art. The method comprises the following specific steps: the first step, catalyzing low molecular alcohol and Propylene Oxide (PO) to generate intermediate polyether polyol by using double metal cyanide complex (DMC) catalyst; and secondly, adding a phosphazene salt catalyst into the polyether polyol as the intermediate, introducing Ethylene Oxide (EO) for end capping reaction, and treating the obtained product with exchange resin and a silicate adsorbent to obtain the polyether polyol with low unsaturation degree and high activity. The polyether polyol with low unsaturation degree and high activity prepared by the invention has the advantages of low unsaturation degree, high primary hydroxyl content and the like, and the prepared polyurethane product has short demolding time and good physical and mechanical properties, and is suitable for being used as materials of automobile interiors and the like.)

1. A preparation method of polyether polyol with low unsaturation degree and high activity is characterized in that: under the action of a catalyst, initiating polymerization of an epoxy compound to obtain polyether polyol with low unsaturation degree and high activity; wherein the catalyst comprises a double metal cyanide complex catalyst and a phosphazenium salt catalyst.

2. The process for preparing a polyether polyol having a low degree of unsaturation and a high activity according to claim 1, wherein: the method comprises the following steps:

(1) adding a double metal cyanide complex catalyst, low molecular alcohol and inorganic acid into a reaction kettle, heating to 100-160 ℃, blowing nitrogen, vacuumizing, stripping and activating the double metal cyanide complex catalyst, adding propylene oxide into the reaction kettle to initiate polymerization reaction, and obtaining an intermediate polyether polyol after the reaction is finished;

(2) reducing the temperature of materials in the reaction kettle to 20-100 ℃, adding a phosphazene salt catalyst methanol solution, blowing nitrogen, vacuumizing and stripping to inactivate the double metal cyanide complex catalyst, heating to 100-;

(3) and adding exchange resin and a silicate adsorbent into the crude polyether polyol for adsorption, removing water and filtering to obtain the polyether polyol product with low unsaturation degree and high activity.

3. The process for preparing a polyether polyol having a low degree of unsaturation and a high activity according to claim 2, wherein: the amount of the double metal cyanide complex catalyst used in step (1) is 0.002-0.01% by weight based on the total weight of the product.

4. The process for preparing a polyether polyol having a low degree of unsaturation and a high activity according to claim 2, wherein: the low molecular alcohol in the step (1) is an active hydrogen compound containing a structural formula-OH, the functionality is 2-3, and the relative molecular mass is 300-4000.

5. The process for preparing a polyether polyol having a low degree of unsaturation and a high activity according to claim 2, wherein: the polyether polyol as the intermediate in the step (1) is an active hydrogen compound containing a structural formula-OH, the functionality is 2-3, and the relative molecular mass is 400-10000.

6. The process for preparing a polyether polyol having a low degree of unsaturation and a high activity according to claim 2, wherein: the amount of the phosphazenium salt catalyst used in the step (2) is 300-5000ppm based on the total weight of the final product.

7. The process for preparing a polyether polyol having a low degree of unsaturation and a high activity according to claim 2, wherein: the amount of the ethylene oxide in the step (2) is 5-30% of the total weight of the product.

8. The process for preparing a polyether polyol having a low degree of unsaturation and a high activity according to claim 2, wherein: the exchange resin in the step (3) is cation exchange resin.

9. The process for preparing a polyether polyol having a low degree of unsaturation and a high activity according to claim 2, wherein: the silicate adsorbent in the step (3) is one or two of a magnesium silicate adsorbent or an aluminum silicate adsorbent.

10. The process for preparing a polyether polyol having a low degree of unsaturation and a high activity according to claim 2, wherein: the polyether polyol with low unsaturation degree and high activity in the step (3) is polyether polyol with the carbon-carbon double bond content of less than 0.03mol/kg and the terminal primary hydroxyl amount accounting for more than 80 percent of the total hydroxyl amount.

Technical Field

The invention belongs to the technical field of polyether polyol synthesis, and particularly relates to a preparation method of polyether polyol with low unsaturation degree and high activity.

Background

Polyether Glycol (PPG) prepared by polymerizing Propylene Oxide (PO) monomers has most of terminal hydroxyl groups as secondary hydroxyl groups, so that the reaction activity is lower when a polyurethane product is prepared, and the hydroxyl concentration is reduced along with the increase of the molecular weight of the PPG, and the Ethylene Oxide (EO) monomer is required to be introduced for blocking to increase the content of primary hydroxyl groups, so that the reaction activity of the product is improved.

The high-activity PPG is prepared by using a traditional KOH catalyst, because KOH can catalyze PO to isomerize into allyl alcohol unit alcohol, the obtained product has high unsaturation degree (generally higher than 0.05mol/kg) and wide relative molecular mass distribution, and more unit alcohol contained in the product can play a role in inhibiting chain growth during foaming, so that the product is difficult to obtain higher resilience. Although PPG prepared by using double metal cyanide complex (DMC) catalyst has low unsaturation degree which can reach below 0.01mol/kg, and has the advantages of relatively narrow molecular mass distribution, low viscosity and the like, DMC catalytic activity is very high, and when EO addition polymerization reaction is carried out by using the DMC catalyst, a small part of PPG molecules have many EO units, a part of PPG molecules have few EO units, and a large part of PPG molecules have no EO units, so that the prepared product has low primary hydroxyl content and relatively wide molecular weight distribution. So that EO capping reactions with DMC catalysts are currently not possible.

A series of phosphazene catalysts including phosphazene base, phosphorus nitrile salt and phosphonitrile oxide are disclosed in Schwesinger et al, German in eighty years of the last century, and all of them are strong organic strong bases and have strong nucleophilicity. The catalytic activity of the phosphazene salt used in the ring-opening polymerization reaction of the epoxide is 450 times that of a KOH catalyst, and the generated polyether polyol has low unsaturation degree and low unit alcohol content, and can catalyze EO end capping reaction and improve the content of terminal primary hydroxyl.

In 2013, 52(1), 39-43, a phosphazene salt catalyst (structural formula 1) was reported in the book of double denier students (Nature science edition):

the product PDI is lower than 1.02, and the unsaturation degree is only 0.03mol/kg, so that the obtained polyurethane product has higher rebound resilience and excellent physical and mechanical properties. The polyether polyol prepared by the three catalyst processes has the following unsaturation degree in order: DMC catalyst < phosphonitrile salt catalyst < KOH catalyst.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: aiming at the problems of low catalytic activity, long production period, more side reactions, high unsaturation degree and the like when the high-activity polyether polyol is prepared by using a KOH catalyst in the prior art, the preparation method of the low-unsaturation-degree high-activity polyether polyol is provided, the low-unsaturation-degree high-activity polyether polyol is prepared by using a DMC catalyst and a phosphonitrile salt catalyst through a two-step method, and the preparation method has the advantages of short production period, less side reactions, low unsaturation degree and high activity.

In order to solve the technical problems, the invention adopts the following technical scheme:

the preparation method of the polyether polyol with low unsaturation degree and high activity comprises the steps of initiating polymerization of epoxy compounds under the action of a catalyst to obtain the polyether polyol with low unsaturation degree and high activity; wherein the catalyst comprises a double metal cyanide complex (DMC) catalyst and a phosphazenium salt catalyst. In the presence of DMC catalyst, low molecular alcohol and propylene oxide are initiated to produce polymerization reaction to obtain intermediate polyether polyol, and the intermediate polyether polyol is then added with phosphazene salt catalyst to deactivate DMC, ethylene oxide is added to produce end capping reaction, and the product is adsorbed with exchange resin and silicate to obtain polyether polyol with low unsaturation degree and high primary hydroxyl group content.

Preferably, the preparation method of the polyether polyol with low unsaturation degree and high activity specifically comprises the following steps:

(1) adding a DMC catalyst, low molecular alcohol and a very small amount of inorganic acid into a reaction kettle, performing leakage test, nitrogen replacement and temperature rise, blowing nitrogen at the temperature of 100-160 ℃, vacuumizing and stripping for 1 hour, activating the double-metal cyanide complex catalyst, then adding propylene oxide into the reaction kettle to initiate polymerization reaction, and obtaining an intermediate polyether polyol after the polymerization reaction is completed;

(2) reducing the temperature of materials in the reaction kettle to 20-100 ℃, adding a phosphazene salt catalyst methanol solution, uniformly stirring, blowing nitrogen, vacuumizing and stripping for 1 hour, inactivating the DMC catalyst by using alkaline phosphazene salt, raising the temperature to 100-130 ℃, introducing ethylene oxide to initiate polymerization, and obtaining crude polyether polyol;

(3) and adding exchange resin and a silicate adsorbent into the crude polyether polyol, adsorbing the residual phosphazene salt catalyst, removing water, and filtering to obtain the low-unsaturation-degree high-activity polyether polyol.

Wherein:

preferably adopts a traditional pressure-resistant kettle type reaction kettle, and has high polymerization activity, short production period and less side reaction.

The DMC catalyst used in step (1) is used in an amount of 0.002 to 0.01%, preferably 0.0025 to 0.005%, based on the total weight of the product.

The low molecular alcohol in the step (1) is an active hydrogen compound containing a structural formula-OH, the functionality is 2-3, the relative molecular mass is 300-4000, and the relative molecular mass is preferably 400-2000.

The intermediate polyether polyol in the step (1) is an active hydrogen compound containing a structural formula-OH, the functionality is 2-3, the relative molecular mass is 400-10000, and the preferred relative molecular mass is 500-8000.

The amount of the phosphazene salt catalyst in the step (2) is 300-5000ppm based on the total weight of the final product.

The amount of ethylene oxide in step (2) is 5-30%, preferably 10-20% by weight of the total weight of the product.

The exchange resin in the step (3) is cation exchange resin, preferably hydrogen type cation exchange resin.

And (4) the silicate adsorbent in the step (3) is one or two of a magnesium silicate adsorbent or an aluminum silicate adsorbent.

The polyether polyol with low unsaturation degree and high activity in the step (3) has the carbon-carbon double bond content of less than 0.03mol/kg, and the terminal primary hydroxyl amount accounts for more than 80 percent of the total hydroxyl amount.

Compared with the prior art, the invention has the following beneficial effects:

1. according to the invention, the double metal cyanide complex catalyst and the phosphonitrile salt catalyst are adopted to cooperate with each other to successively catalyze the polymerization of low molecular alcohol, propylene oxide and ethylene oxide, so that the high-activity polyether polyol with lower unsaturation degree and higher primary hydroxyl content can be obtained, and the prepared polyurethane product has short demolding time and good physical and mechanical properties, and is suitable for being used as materials of automobile interiors and the like.

2. The polyether polyol with low unsaturation degree and high activity prepared by the invention has the unsaturation degree of 0.015-0.025mol/kg and the primary hydroxyl content of more than 80 percent.

Detailed Description

The present invention will be further described with reference to the following examples.

All the raw materials used in the examples are commercially available unless otherwise specified.

Example 1

200g of polyether polyol having a functionality of 2 and a relative molecular mass of 400, 0.06g of DMC catalyst and 0.02g of phosphoric acid are placed in a 3-liter autoclave equipped with a pressure gauge, a thermometer and a stirrer. After leakage testing and nitrogen replacement, introducing nitrogen at the bottom when the temperature rises to 100 ℃, vacuumizing and stripping for 1h to activate the catalyst, continuously adding 1500g of propylene oxide for 6h when the temperature rises to 130 ℃, and curing for 1h after finishing. Pumping unreacted monomers by using a vacuum pump, cooling to 80 ℃, adding 3g of phosphazene salt catalyst methanol solution, heating to 95 ℃, stripping for 1h to remove methanol, continuously introducing 300g of ethylene oxide for 2h when the temperature is 115 ℃, performing curing reaction for 1h, pumping the unreacted monomers by using the vacuum pump, adding 1 percent of hydrogen type cation exchange resin and 0.4 percent of aluminum silicate adsorbent by total weight, removing water and filtering to obtain the polyether polyol with the unsaturation degree of 0.02mol/kg and the primary hydroxyl content of 85%.

Example 2

200g of polyether polyol having a functionality of 3 and a relative molecular mass of 500, 0.06g of DMC catalyst and 0.02g of phosphoric acid are placed in a 3-liter autoclave equipped with a pressure gauge, a thermometer and a stirrer. After leakage testing and nitrogen replacement, introducing nitrogen at the bottom when the temperature rises to 100 ℃, vacuumizing and stripping for 1h to activate the catalyst, continuously adding 1400g of propylene oxide for 6h when the temperature rises to 130 ℃, and curing for 1h after finishing. Pumping unreacted monomers by using a vacuum pump, cooling to 80 ℃, adding 3g of phosphazene salt catalyst methanol solution, heating to 95 ℃, stripping for 1h to remove methanol, continuously introducing 400g of ethylene oxide for 2h when the temperature is 115 ℃, performing curing reaction for 1h, pumping the unreacted monomers by using the vacuum pump, adding 1 percent of hydrogen type cation exchange resin and 0.4 percent of magnesium silicate adsorbent by weight, removing water and filtering to obtain the polyether polyol with the unsaturation degree of 0.018mol/kg and the primary hydroxyl content of 89%.

Example 3

200g of polyether polyol having a functionality of 2 and a relative molecular mass of 800, 0.06g of DMC catalyst and 0.02g of phosphoric acid are placed in a 3-liter autoclave equipped with a pressure gauge, a thermometer and a stirring device. After leakage testing and nitrogen replacement, introducing nitrogen at the bottom when the temperature rises to 100 ℃, vacuumizing and stripping for 1h to activate the catalyst, continuously adding 1600g of propylene oxide for 6h when the temperature rises to 130 ℃, and curing for 1h after finishing. Pumping unreacted monomers by using a vacuum pump, cooling to 80 ℃, adding 3g of phosphazene salt catalyst methanol solution, heating to 95 ℃, stripping for 1h to remove methanol, continuously introducing 200g of ethylene oxide for 2h when the temperature is 115 ℃, performing curing reaction for 1h, pumping the unreacted monomers by using the vacuum pump, adding 1 percent of hydrogen type cation exchange resin, 0.2 percent of aluminum silicate adsorbent and 0.2 percent of magnesium silicate adsorbent according to the total weight, removing water, and filtering to obtain the polyether polyol with the unsaturation degree of 0.021mol/kg and the primary hydroxyl content of 82%.

Comparative example 1

200g of polyether polyol having a functionality of 2 and a relative molecular mass of 400, 0.07g of DMC catalyst and 0.02g of phosphoric acid were placed in a 3-liter autoclave equipped with a pressure gauge, a thermometer and a stirrer. After leakage testing and nitrogen replacement, introducing nitrogen at the bottom when the temperature rises to 100 ℃, vacuumizing and stripping for 1h to activate the catalyst, continuously adding 1800g of propylene oxide for 8h when the temperature rises to 130 ℃, and curing for 1h after finishing. Unreacted monomers are pumped by a vacuum pump, and the obtained polyether polyol has the unsaturation degree of 0.008mol/kg and the primary hydroxyl content of 5 percent.

Comparative example 2

200g of polyether polyol having a functionality of 2 and a relative molecular mass of 400 and 5g of KOH catalyst were placed in a 3-liter autoclave equipped with a pressure gauge, a thermometer and a stirrer. After leakage testing and nitrogen replacement, introducing nitrogen at the bottom when the temperature is raised to 110 ℃, vacuumizing and stripping for 1h for dehydration, continuously adding 1500g of propylene oxide for 8h, and curing for 1h after finishing. Pumping unreacted monomers by using a vacuum pump, heating to 115 ℃, continuously introducing 300g of ethylene oxide for 2h, curing for 1h, pumping the unreacted monomers by using the vacuum pump, adding 120g of water, stirring for 0.5h, adding 12.7g of 70% phosphoric acid, stirring for 1h, adding 2g of magnesium silicate adsorbent and 1g of aluminum silicate adsorbent, stirring for 0.5h, vacuumizing to remove moisture, and filtering to obtain the polyether polyol with the unsaturation degree of 0.052mol/kg and the primary hydroxyl content of 76%.

Comparative example 3

200g of polyether polyol with the functionality of 2 and the relative molecular mass of 400 and 3g of methanol solution of a phosphazene salt catalyst are added into a 3-liter autoclave provided with a pressure gauge, a thermometer and a stirring device. After leakage testing and nitrogen replacement, heating to 95 ℃, stripping for 1h to remove methanol, when the temperature is raised to 110 ℃, continuously adding 1500g of propylene oxide for 8h, and after finishing the aging reaction for 1 h. Pumping unreacted monomers by using a vacuum pump, heating to 115 ℃, continuously introducing 300g of ethylene oxide for 2h, curing for 1h, pumping the unreacted monomers by using the vacuum pump, adding 1 percent of cation exchange resin and 0.4 percent of aluminum silicate adsorbent by total weight, removing water and filtering to obtain the polyether polyol with the unsaturation degree of 0.033mol/kg and the primary hydroxyl content of 85 percent.

The product properties of examples 1-3 and comparative examples 1-3 are shown in Table 1.

TABLE 1 Properties of the products of examples 1-3 and comparative examples 1-3

As can be seen from the table 1, the polyether polyol with low unsaturation degree and high activity is prepared by using a DMC catalyst and a phosphazene salt catalyst through a two-step method, the unsaturation degree of the obtained polyether polyol is obviously reduced, the primary hydroxyl content is higher, the polyether polyol is superior to conventional products in the market, and the application prospect is wide.

Of course, the foregoing is only a preferred embodiment of the invention and should not be taken as limiting the scope of the embodiments of the invention. The present invention is not limited to the above examples, and equivalent changes and modifications made by those skilled in the art within the spirit and scope of the present invention should be construed as being included in the scope of the present invention.