A broad molecular weight distribution fatty alcohol random polyether and a method for preparing the same

Abstract

The present application relates to a kind of preparation methods of wide molecular weight distribution fatty alcohol random polyether, the method includes the following steps: mixing strong base catalyst with fatty alcohol, under the condition of temperature 115~120 ℃, vacuum degree >=-0.095MPa, dehydration 1~2h, add alkylene oxide and react at 90~130 ℃, degassing and get fatty alcohol random polyether intermediate;Fatty alcohol random polyether intermediate is removed by adsorption filtration after removing impurity ions, obtain the fatty alcohol random polyether intermediate removed K + , Na + And other impurity ions;Fatty alcohol random polyether intermediate removed impurity ions and acid auxiliary are mixed, under the condition of temperature 115~120 ℃, vacuum degree >=-0.095MPa, dehydration 1~2h, add DMC and heat to 120~150 ℃, then add alkylene oxide, degassing and get fatty alcohol random polyether.The fatty alcohol random polyether obtained in the application is wider than the fatty alcohol random polyether prepared directly using DMC or strong base catalyst under the same reaction conditions, and the molecular weight distribution coefficient can break through 1.2, even higher.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of synthetic surfactants, in particular to a wide molecular weight distribution fatty alcohol random polyether and a preparation method thereof. BACKGROUND

[0002] The traditional fatty alcohol polyether preparation method uses strong alkali as a catalyst, such as sodium hydroxide, potassium hydroxide, sodium methoxide, potassium methoxide, and metal potassium and sodium. Due to the reaction characteristics of the strong alkali catalyst, the speed of chain initiation reaction is lower than that of chain growth reaction, so the polyether chain has grown up before all initiators are completely converted into monohydric adducts, resulting in not only the residual of initiators in the final product but also the wide molecular weight distribution of the adduct number.

[0003] Compared with the traditional alkali catalyst, the use of double metal cyanide catalyst (DMC) for synthesizing polyether has the advantages of high molecular weight, low unsaturation, high average functionality, and narrow molecular weight distribution, because there is a high-speed chain transfer between the hydroxyl group and the active center in the system, and the end group rearrangement in polymerization is eliminated, avoiding the reduction of hydroxyl functionality.

[0004] Based on this principle, the molecular weight distribution characteristics of fatty alcohol polyether synthesized by the two single catalysts are obvious and basically fixed in their respective specific areas, and it is difficult to expand to a larger range. However, from the application field of polyether, the system needs to meet a variety of requirements, so there is a diversified demand for the molecular weight distribution of fatty alcohol polyether, not just limited to narrow distribution polyether. In order to meet the compatibility requirements, the market also seeks wide distribution polyether, and it is necessary to flexibly adjust the molecular weight distribution of fatty alcohol polyether. SUMMARY

[0005] Therefore, the present application aims to overcome the limitations of the molecular weight distribution of fatty alcohol random polyether prepared by the existing process, and provides a wide molecular weight distribution fatty alcohol random polyether and a preparation method thereof.

[0006] To achieve the above technical purposes, the technical solutions adopted by the present application are as follows:

[0007] In a first aspect, the present application provides a preparation method of a wide molecular weight distribution fatty alcohol random polyether, which comprises the following steps:

[0008] Step 1: mixing a strong alkali catalyst with a fatty alcohol, dehydrating under the condition of N2, temperature 115-120℃, and vacuum degree≧-0.095MPa for 1-2h, adding an alkylene oxide to react at 90-130℃, degassing and discharging to obtain a fatty alcohol random polyether intermediate;

[0009] Step 2: removing impurity ions by adsorption and then filtration to obtain a fatty alcohol random polyether intermediate with impurity ions removed;

[0010] Step 3, the impurity ion-removed fatty alcohol random polyether intermediate and the acidic auxiliary agent are mixed, dehydrated under the condition of N2, temperature 115-120℃, vacuum degree ≧-0.095MPa for 1-2h, double metal cyanide catalyst DMC is added, heated to 120-150℃, then the alkylene oxide is added, and the product is discharged after degassing.

[0011] Further, the fatty alcohol in step 1 is at least one of linear or branched fatty alcohol with carbon number of 10-18.

[0012] Further, the strong base catalyst in step 1 is at least one of sodium hydroxide, potassium hydroxide, sodium methoxide, potassium methoxide, metallic potassium, and metallic sodium, and the amount of the strong base catalyst is 1-5‰ of the total weight of the fatty alcohol and the alkylene oxide.

[0013] Further, the molecular weight of the fatty alcohol random polyether intermediate in step 1 is 20-30% of the molecular weight of the finished fatty alcohol random polyether.

[0014] Further, the adsorption process in step 2 is: after adding distilled water and acetic acid to the fatty alcohol random polyether intermediate in step 1, mixing and stirring at 50-70℃ for 20-30min, adding the adsorbent and adsorbing and stirring at 70-80℃ for 30-60min; dehydrating at a temperature of 100-115℃ and a vacuum degree of ≧-0.095MPa until the water content is <0.05%; and the amount of the distilled water is 2-10% of the mass of the fatty alcohol random polyether intermediate.

[0015] Further, the adsorbent is composed of an adsorbent main body and a modified ligand, the adsorbent main body is at least one of α-Al2O3, amorphous silica, magnesium silicate, aluminum silicate, or magnesium aluminum silicate; the ligand is at least one of magnesium acetate, calcium acetate, calcium chloride, copper chloride, potassium chloride, magnesium nitrate, or aluminum nitrate; and the amount of the adsorbent added is 0.1-1% of the mass of the fatty alcohol random polyether intermediate.

[0016] Further, the acidic auxiliary agent in step 3 is at least one of phosphoric acid, sulfuric acid, acetic acid, citric acid, nitric acid, hydrochloric acid, and formic acid.

[0017] Further, the amount of the DMC in step 3 is 10-100ppm of the total mass of the molecular weight of the finished fatty alcohol random polyether; and the mass ratio of the acidic auxiliary agent to the DMC in step 3 is (1-10):1.

[0018] Preferably, the alkylene oxide in steps 1 and 3 is a mixture of ethylene oxide and propylene oxide.

[0019] Preferably, the mass of ethylene oxide is 10-30% of the total mass of the alkylene oxide.

[0020] In a second aspect, the present application provides a wide molecular weight distribution fatty alcohol random polyether, the molecular weight distribution coefficient of which is 1.2-1.5, and which is prepared by the above method for preparing a wide molecular weight distribution fatty alcohol random polyether.

[0021] The beneficial effects of the present application are as follows:

[0022] 1. The present application can obtain a fatty alcohol random polyether with a wider molecular weight distribution, which is wider than that prepared directly by DMC or strong base catalysis under the same reaction conditions, and the molecular weight distribution coefficient can break through 1.2, even higher.

[0023] 2. The present application can also control the molecular weight distribution of the fatty alcohol random polyether by adjusting the mass ratio of the acidic adjuvant and DMC, so as to meet the compatibility requirements of the market for the diversification of the molecular weight distribution of the fatty alcohol polyether.

[0024] 3. In the present application, a strong base catalyst is used to catalyze an intermediate, which is to control the by-products of the product. Because the product has by-products when catalyzed by DMC in one step under acidic adjuvant, the most intuitive manifestation is that the reaction solution is turbid. The product obtained by using a strong base catalyst to catalyze an intermediate and then adsorbing and treating, and then catalyzing by DMC, is clear in appearance. DETAILED DESCRIPTION

[0025] In the description of the present application, it should be noted that the specific conditions not indicated in the examples are carried out according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments not indicated by the manufacturer are all conventional products that can be purchased on the market.

[0026] The molecular weight distribution of the fatty alcohol random polyether is detected by GPC, represented by D(Mw / Mn), and the detection conditions are as follows: column combination (length 65 cm), temperature 30℃, THF as mobile phase, flow rate 1 ml / min, sample concentration 10 g / L, and RI detector. (Length 65 cm), temperature 30℃, THF as mobile phase, flow rate 1 ml / min, sample concentration 10 g / L, and RI detector.

[0027] In the present application, the molecular weight of the fatty alcohol random polyether intermediate is controlled to be 20-30% of the molecular weight of the finished fatty alcohol random polyether by the alkali catalysis process, and the feeding amount of the fatty alcohol and the alkylene oxide in the synthesis process is determined according to the designed molecular weight of the finished fatty alcohol random polyether. Then, the intermediate is adsorbed and treated, and then catalyzed by DMC under acidic adjuvant to produce a wide distribution fatty alcohol random polyether. This process constructs an intermediate, which can effectively control the generation of by-products and save costs.

[0028] The application will be further described in conjunction with specific examples which are intended to explain but not limit the application.

[0029] Example 1

[0030] This example relates to a method for preparing a wide molecular weight distribution fatty alcohol random polyether, the steps are as follows:

[0031] Step 1, 3.36g catalyst KOH and 500g C 18 -C 16 alcohol are added to a 2.5L polymerization reactor, dehydrated at 115-120℃, -0.096Mpa for 1.5h, then heated to 115℃ to start continuous addition of 136g of uniform mixture of ethylene oxide and 483g of propylene oxide, the reaction control stage keeps the reaction temperature at 115-120℃, after the mixture is added, continue to react until the pressure drop is stable, finally cool and degas to 60℃, filter to obtain C 18 -C 16 alcohol random polyether intermediate (design molecular weight 600);

[0032] Step 2, 500g C 18 -C 16 alcohol random polyether intermediate is added to a 1000mL four-necked glass flask, 1.6g of acetic acid (98wt%) and 15g of distilled water are added at the same time, heated and stirred at 60℃ for 30min, then 1.5g of adsorbent of main body magnesium aluminum silicate / ligand calcium chloride is added, stirred and adsorbed at 75℃ for 60min, gradually heated to 115℃, vacuum dehydrated for 4h, after dehydration, the water content is less than 0.04%, then filtered to obtain C + , Na + alcohol random polyether intermediate after treatment with K 18 -C 16 alcohol random polyether intermediate after treatment with K

[0033] Step 3, 300g of C 18 -C 16 alcohol random polyether intermediate after treatment and 60ppm of acidic auxiliary phosphoric acid based on the total mass of target product in the reactor are added to a 2.5L polymerization reactor, dehydrated at 115-120℃, -0.096Mpa for 1.5h, then 40ppm of DMC based on the total mass of target product in the reactor is added (the mass ratio of auxiliary and DMC is kept at 1.5:1), heated to 130℃ to start continuous addition of 176g of uniform mixture of ethylene oxide and 624g of propylene oxide, the reaction control stage keeps the reaction temperature at 130-135℃, after the mixture is added, continue to react until the pressure drop is stable, finally cool and degas to 60℃, filter to obtain C 18 -C 16Alcohol random polyether end product (design molecular weight 2200), yield 97.2%. The molecular weight distribution D = 1.20 was detected by GPC.

[0034] Example 2

[0035] Step 1, 2.07 g of catalyst KOH and 350 g of lauryl alcohol were added to a 2.5 L polymerization reactor, and dehydrated at 115-120 °C, -0.096 MPa for 1.5 h, then the temperature was raised to 115 °C to start continuous addition of 137 g of uniform mixture of ethylene oxide and 549 g of propylene oxide, and the reaction temperature was kept at 115-120 °C in the control stage, and after the addition of the mixture was completed, the reaction was continued until the pressure drop was stable, and finally the temperature was lowered to 60 °C and dehydrated, and the lauryl alcohol random polyether intermediate (design molecular weight 550) was obtained by filtration;

[0036] Step 2, 500 g of lauryl alcohol random polyether intermediate was added to a 1000 mL four-necked glass flask, 1.10 g of acetic acid (98 wt%) and 20 g of distilled water were added, heated and stirred at 60 °C for 30 min, then 1.2 g of adsorbent of main body aluminum silicate / ligand calcium acetate was added, stirred and adsorbed at 70 °C for 60 min, gradually heated to 110 °C, vacuum dehydrated for 3 h, and after the water content was less than 0.04%, the pH was 7.02, K + , Na + content of the post-treated lauryl alcohol random polyether intermediate was less than 10 ppm;

[0037] Step 3, 150 g of post-treated lauryl alcohol intermediate and 100 ppm of acidic auxiliary sulfuric acid based on the total mass of target product in the reactor were added to a 2.5 L polymerization reactor, and dehydrated at 115-120 °C, -0.096 MPa for 1.5 h, then 40 ppm of DMC based on the total mass of target product in the reactor was added (the mass ratio of auxiliary and DMC was kept at 2.5:1), and the temperature was raised to 130 °C to start continuous addition of 325 g of uniform mixture of ethylene oxide and 1299 g of propylene oxide, and the reaction temperature was kept at 130-135 °C in the control stage, and after the addition of the mixture was completed, the reaction was continued until the pressure drop was stable, and finally the temperature was lowered to 60 °C and dehydrated, and the lauryl alcohol random polyether (design molecular weight 2200) was obtained by filtration, with a yield of 97.3%. The molecular weight distribution D = 1.23 was detected by GPC.

[0038] Example 3

[0039] The amount of acidic auxiliary in Example 2 was changed to 120 ppm of acidic auxiliary based on the total mass of target product, and the mass ratio of auxiliary and DMC was kept at 3:1. The molecular weight distribution D = 1.27 was detected by GPC. The yield reached 97.1%.

[0040] Example 4

[0041] The amount of acidic promoter in Example 2 was changed to 160 ppm of the total mass of the target product, and the mass ratio of the promoter to DMC was kept at 4:1. The molecular weight distribution D = 1.32 was detected by GPC. The yield reached 97.0%.

[0042] Example 5

[0043] The amount of acidic promoter in Example 2 was changed to 400 ppm of the total mass of the target product, and the mass ratio of the promoter to DMC was kept at 10:1. The molecular weight distribution D = 1.47 was detected by GPC. The yield reached 97.1%.

[0044] Comparative Example 1

[0045] 5.3 g of catalyst KOH and 150 g of lauryl alcohol were added to a 2.5 L polymerization reactor, and warmed and stirred at -0.096 MPa for 1.5 h at 115-120°C. Then, a uniform mixture of 325 g of ethylene oxide and 1299 g of propylene oxide was continuously added, and the reaction temperature was kept at 115-120°C during the reaction control stage. After the addition of the mixture was completed, the reaction was continued until the pressure drop stabilized, and then the temperature was lowered to 60°C for degassing. Lauryl alcohol random polyether (design molecular weight 2200) was obtained by filtration, and the yield was 97.5%. The molecular weight distribution D = 1.13 was detected by GPC.

[0046] Comparative Example 2

[0047] 150 g of lauryl alcohol was added to a 2.5 L polymerization reactor, and warmed and stirred at -0.096 MPa for 1.5 h at 115-120°C. Then, 40 ppm of DMC based on the total mass of the target product in the reactor was added, and the temperature was raised to 130°C. A uniform mixture of 325 g of ethylene oxide and 1299 g of propylene oxide was continuously added, and the reaction temperature was kept at 130-135°C during the reaction control stage. After the addition of the mixture was completed, the reaction was continued until the pressure drop stabilized, and then the temperature was lowered to 60°C for degassing. Lauryl alcohol random polyether (design molecular weight 2200) was obtained by filtration, and the yield was 97.7%. The molecular weight distribution D = 1.04 was detected by GPC.

[0048] Comparative Example 3

[0049] The fatty alcohol in Comparative Example 1 was changed to C 12 -C 14 alcohol, the catalyst KOH was changed to 4.9 g, and the alkylene oxide was changed to a uniform mixture of 450 g of ethylene oxide and 1050 g of propylene oxide, and the other conditions were unchanged. The molecular weight distribution D = 1.16 was detected by GPC. The yield reached 97.3%.

[0050] Comparative Example 4

[0051] The fatty alcohol in the comparative example 2 is C 12 -C 14 alcohol, the oxidized alkylene is changed to a uniform mixture of 450 g of ethylene oxide and 1050 g of propylene oxide, and other conditions remain unchanged. The molecular weight distribution D = 1.03 is detected by GPC. The yield reaches 97.5%.

[0052] Comparative example 5

[0053] The fatty alcohol in the comparative example 1 is changed to C 18 -C 16 alcohol, the catalyst KOH is changed to 3.7 g, the oxidized alkylene is changed to a uniform mixture of 238 g of ethylene oxide and 843 g of propylene oxide, and other conditions remain unchanged. The molecular weight distribution D = 1.15 is detected by GPC. The yield reaches 97.3%.

[0054] Comparative example 6

[0055] The fatty alcohol in the comparative example 2 is changed to C 18 -C 16 alcohol, the oxidized alkylene is changed to a uniform mixture of 238 g of ethylene oxide and 843 g of propylene oxide, and other conditions remain unchanged. The molecular weight distribution D = 1.05 is detected by GPC. The yield reaches 97.4%.

[0056] Comparative example 7

[0057] 150 g of lauryl alcohol and 60 ppm of an acidic auxiliary phosphoric acid based on the total mass of the target product in the kettle are added to a 2.5 L polymerization kettle, and other conditions remain unchanged. The molecular weight distribution D = 1.22 is detected by GPC. The product is turbid with white suspended matter, and the yield only reaches 95.3%.

[0058] From the comparative examples 1, 3, 5, it can be seen that the molecular weight distribution D of the fatty alcohol random polyether prepared by using the strong base catalyst KOH is between 1.1 and 1.2; from the comparative examples 2, 4, 6, it can be seen that the molecular weight distribution D of the fatty alcohol random polyether prepared by using the catalyst DMC is stably within 1.1. It can be seen that the molecular weight distribution characteristics of the fatty alcohol random polyether synthesized by using the two single catalysts are obvious and are basically fixed in their respective specific ranges, and it is difficult to expand to a larger range; from the comparative example 7, it can be seen that there is a significant by-product in the direct synthesis of the fatty alcohol random polyether by using DMC in the presence of an acidic auxiliary. However, by the preparation method introduced in the present application, the fatty alcohol random polyether with a molecular weight distribution D breaking 1.2 can be synthesized by constructing a polyether intermediate and using the limiting effect of the acidic auxiliary on DMC, and no by-product is generated, which is difficult to achieve by the comparative method. Moreover, by adjusting the proportion of the auxiliary and the catalyst, the polyether with a specific molecular weight distribution can be synthesized to meet the diversified matching requirements.

[0059] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the patent scope of the present application. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, several modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A method for preparing a wide molecular weight distribution fatty alcohol random polyether, characterized in that: The method includes the following steps: Step 1: Mix a strong base catalyst with a fatty alcohol, pass N2 through, and dehydrate for 1-2 hours at a temperature of 115-120℃ and a vacuum degree ≥-0.095MPa. Add an oxidized olefin and react at 90-130℃. Degas and discharge to obtain a fatty alcohol random polyether intermediate. Step 2: The fatty alcohol random polyether intermediate is adsorbed and then filtered to remove impurity ions, thus obtaining the fatty alcohol random polyether intermediate with impurity ions removed. Step 3: Mix the fatty alcohol random polyether intermediate with impurity ions removed and the acidic additive, pass N2 through, and dehydrate for 1-2 hours at a temperature of 115-120℃ and a vacuum degree of ≥-0.095MPa. Add the bimetallic cyanide catalyst DMC, raise the temperature to 120-150℃, and then add olefin oxide. Degas and discharge to obtain fatty alcohol random polyether. The fatty alcohol is at least one of straight-chain or branched fatty alcohols with 10 to 18 carbon atoms; The molecular weight of the fatty alcohol random polyether intermediate is 20-30% of the molecular weight of its finished fatty alcohol random polyether. In step 2, the adsorption process is as follows: distilled water and acetic acid are added to the fatty alcohol random polyether intermediate, and the mixture is stirred at 50-70°C for 20-30 minutes. Then, the adsorbent is added and the mixture is stirred at 70-80°C for 30-60 minutes. The mixture is then dehydrated to a water content of <0.05% at a temperature of 100-115°C and a vacuum degree of ≥-0.095MPa. The adsorbent is composed of an adsorbent matrix and a modified ligand. The adsorbent matrix is ​​at least one of α-Al2O3, amorphous silica, magnesium silicate, aluminum silicate, or magnesium aluminum silicate; the ligand is at least one of magnesium acetate, calcium acetate, calcium chloride, copper chloride, potassium chloride, magnesium nitrate, or aluminum nitrate. The oxidized olefin is a mixture of ethylene oxide and propylene oxide; The mass ratio of the acidic additive to DMC is (1-10):

1.

2. The method for preparing a wide molecular weight distribution fatty alcohol random polyether according to claim 1, characterized in that: The strong base catalyst is at least one of sodium hydroxide, potassium hydroxide, sodium methoxide, potassium methoxide, metallic potassium, and metallic sodium, and the amount of the strong base catalyst is 1 to 5‰ of the total weight of the fatty alcohol and oxidized olefin.

3. The method for preparing a wide molecular weight distribution fatty alcohol random polyether according to claim 1, characterized in that: The amount of distilled water added during the adsorption process is 2-10% of the mass of the fatty alcohol random polyether intermediate.

4. The method for preparing a wide molecular weight distribution fatty alcohol random polyether according to claim 1, characterized in that: The amount of adsorbent added is 0.1% to 1% of the mass of the fatty alcohol random polyether intermediate.

5. The method for preparing a wide molecular weight distribution fatty alcohol random polyether according to claim 1, characterized in that: The amount of DMC used is 10 to 100 ppm of the total molecular weight of the finished fatty alcohol random polyether.

6. The method for preparing a wide molecular weight distribution fatty alcohol random polyether according to claim 5, characterized in that: The acidic additive is at least one of phosphoric acid, sulfuric acid, acetic acid, citric acid, nitric acid, hydrochloric acid, and formic acid.

7. The method for preparing a wide molecular weight distribution fatty alcohol random polyether according to claim 1, characterized in that: In the oxidized olefins, ethylene oxide accounts for 10-30% of the total mass of the oxidized olefins.

8. A fatty alcohol random polyether with a wide molecular weight distribution, characterized in that: The fatty alcohol random polyether has a molecular weight distribution coefficient of 1.2 to 1.5 and is obtained by the preparation method described in any one of claims 1 to 7.