An acidic catalyst, a method for its preparation, and its method and use for the preparation of castor oil polyether polyols having a high primary hydroxyl content

Abstract

The application provides an acid catalyst which is an activated carbon loaded metal catalyst. By using the acid catalyst, a castor oil polyether polyol with a content of terminal primary hydroxyl groups exceeding 92% and an average molecular weight of 3000-5000 is synthesized by catalyzing the ring opening and end capping of EO. The polyether polyol has high reactivity when applied to high resilience polyurethane foam, has small foaming collapse, has excellent physical properties of the prepared foam, and has high bio-based content of the foam, thereby meeting the development trend of green and low carbon.

Description

Technical Field

[0001] This invention belongs to the field of bio-based polyether synthesis, specifically relating to an acidic catalyst, its preparation method, and its use in preparing castor oil polyether polyols with high primary hydroxyl content. Background Technology

[0002] With petroleum resources dwindling and becoming increasingly scarce, the synthesis of polyether polyols using bio-based raw materials has garnered significant attention. European and American countries already have policies requiring that the bio-based content of high-resilience polyurethane materials used in automotive seats must exceed 5%. Castor oil, as a natural plant oil containing multiple hydroxyl groups, meets the policy requirements of European and American countries when used as an initiator to synthesize polyether polyols. However, currently, most castor oil polyether polyols synthesized domestically and internationally have secondary hydroxyl groups at the terminal end, with very few primary hydroxyl groups. When used in high-resilience polyurethane, this results in low reactivity, leading to significant foam shrinkage and even bubble collapse, making it unsuitable for use in high-end automotive seats.

[0003] The paper "Application of Castor Oil Polyether Polyols in Polyurethane Flexible Foam" (He Ming et al., DOI:10.3969 / j.issn.1005-1902.2009.06.009) reported the use of castor oil as an initiator and bimetallic catalyst (DMC) to catalyze the ring-opening of propylene oxide (PO) to synthesize castor oil polyether polyols with a molecular weight of 2000-6000. However, this method does not involve ethylene oxide (EO) in the reaction, and the terminal hydroxyl groups are secondary hydroxyl groups with extremely low primary hydroxyl content, making it unsuitable for use in high-resilience polyurethane. CN102532513A discloses a method for synthesizing high molecular weight castor oil polyether polyols. The first step involves using DMC to catalyze the ring-opening synthesis of PO to synthesize low molecular weight castor oil polyether polyols. The second step involves feeding a mixture of EO and PO to copolymerize the polyether polyol. Although this method uses a mixture of EO and PO as feed, due to the high reactivity of EO, EO reacts preferentially during the reaction process. As a result, the polyether polyols obtained are still mostly PO-terminated, leading to a very low primary hydroxyl content in the product.

[0004] Therefore, there is still a need in this field to research and develop castor oil polyether polyols with high primary hydroxyl content, so as to obtain high-resilience polyurethane foam while conforming to the green and low-carbon development trend. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide an acidic catalyst, its preparation method, and its application in preparing castor oil polyether polyols with high primary hydroxyl content. Using the acidic catalyst described in this invention, castor oil polyether polyols with a terminal primary hydroxyl content exceeding 92% and an average molecular weight of 3000-5000 are synthesized by ring-opening and end-capping of EO. These polyether polyols exhibit high reactivity and minimal foam shrinkage when applied to high-resilience polyurethane foams. The resulting foams possess excellent physical properties (tensile strength, tear strength, elongation at break, etc.) and high bio-based content, aligning with the green and low-carbon development trend.

[0006] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0007] This invention provides an acidic catalyst, which is a metal catalyst supported on activated carbon, with the molecular formula M. a H b PV x W 12-x O d / C, where M is an alkali metal or alkaline earth metal, 1≤a≤3, 1≤b≤2, 40≤d≤45, 2≤x≤10.

[0008] The acidic catalyst according to the present invention, wherein M includes, but is not limited to, sodium or potassium.

[0009] According to the acidic catalyst of the present invention, wherein the molecular formula of the acidic catalyst is M a H b PV x W 12-x O d In / C, a is any number between 1 and 3, for example, a is 1, 1.2, 1.5, 1.8, 2.0, 2.2, 2.5, 2.8, or 3; b is any number between 1 and 2, for example, b is 1, 1.2, 1.5, 1.8, or 2; d is any number between 40 and 45, for example, d is 40, 40.5, 41, 41.5, 42, 42.5, 43, 43.5, 44, 44.5, or 45; x is any number between 2 and 10, for example, x is 2, 2.2, 2.5, 2.8, 3, 3.2, 3.5, 3.8, 4, 4.2, 4.5, 4.8, 5, 5.2, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 8.7, 8.9, 9, 9.2, 9.5, 9.8, or 10.

[0010] This invention also provides a method for preparing an acidic catalyst, comprising the following steps:

[0011] 1) Synthesis of catalyst precursor: Soluble phosphate, soluble vanadium salt, and soluble tungsten salt are added to water and heated and stirred under acidic conditions. After the reaction is completed, the preferred post-treatment is cooling, extraction, and drying to obtain the catalyst precursor with the molecular formula M. a H b PV x W 12-x O d ;

[0012] 2) Activated carbon support: Activated carbon and catalyst precursor are added to water, stirred and impregnated, the water is evaporated after impregnation, and the dried material is activated to obtain an acidic catalyst with the molecular formula M. a H b PV x W 12-x O d / C;

[0013] Where M is an alkali metal or alkaline earth metal, 1≤a≤3, 1≤b≤2, 40≤d≤45, 2≤x≤10.

[0014] According to the method for preparing the acidic catalyst of the present invention, in step 1),

[0015] Preferably, M includes, but is not limited to, sodium and potassium;

[0016] Preferably, the soluble phosphates include, but are not limited to, one or more of NaH2PO4, Na2HPO4, KH2PO4, and K2HPO4; the soluble vanadium salts include, but are not limited to, one or more of NaVO3, KVO3, and NH4VO3; and the soluble tungsten salts include, but are not limited to, Na2WO4, K2WO4, and (NH4)6W7O. 24 One or more of the following;

[0017] Preferably, the molecular formula of the acidic catalyst is M a H b PV x W 12-x O dIn / C, a is any number between 1 and 3, for example, a is 1, 1.2, 1.5, 1.8, 2.0, 2.2, 2.5, 2.8, or 3; b is any number between 1 and 2, for example, b is 1, 1.2, 1.5, 1.8, or 2; d is any number between 40 and 45, for example, d is 40, 40.5, 41, 41.5, 42, 42.5, 43, 43.5, 44, 44.5, or 45; x is any number between 2 and 10, for example, x is 2, 2.2, 2.5, 2.8, 3, 3.2, 3.5, 3.8, 4, 4.2, 4.5, 4.8, 5, 5.2, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 8.7, 8.9, 9, 9.2, 9.5, 9.8, or 10;

[0018] Preferably, the molar ratio of soluble phosphate to soluble vanadium salt is 1:2-10; the molar ratio of soluble vanadium salt to soluble tungsten salt is 1:0.2-6.

[0019] Preferably, the acidic conditions are adjusted by an acidity regulator, wherein the acidity regulator is concentrated sulfuric acid, concentrated nitric acid, concentrated hydrochloric acid, etc.; the pH range of the acidic conditions is pH 1-5;

[0020] Preferably, the reaction temperature is 40-80℃; the reaction time is 1-10h;

[0021] Preferably, the solvent used for extraction is acetone, diethyl ether, n-hexane, etc.

[0022] According to the method for preparing the acidic catalyst of the present invention, in step 2),

[0023] Preferably, the activated carbon is selected from coconut shell activated carbon, peanut shell activated carbon, walnut shell activated carbon, etc., and the mesh size of the activated carbon is 20-100 mesh, for example, 20-40 mesh, 40-60 mesh, 60-80 mesh, or 80-100 mesh.

[0024] Preferably, the amount of activated carbon used is 100%-2000% of the mass of the catalyst precursor, more preferably 500%-1000%;

[0025] Preferably, the temperature for stirring and impregnation is 60-90℃, more preferably 60-80℃; the time for stirring and impregnation is 10-24 hours.

[0026] Preferably, activation is carried out in a nitrogen atmosphere, or in a nitrogen atmosphere containing 1-10% (volume fraction) oxygen;

[0027] Preferably, the activation temperature is 600-1200℃; the activation time is 4-10h.

[0028] The present invention also provides a castor oil polyether polyol, the structural formula of which is as follows:

[0029]

[0030] Where m = 20 - 60, n = 20 - 40.

[0031] According to the castor oil polyether polyol of the present invention, the castor oil polyether polyol has a molecular weight of 3000-5000, and the content of terminal primary hydroxyl groups of the castor oil polyether polyol is greater than 92%, preferably greater than 95%, and more preferably greater than 98%.

[0032] This invention also provides a method for preparing castor oil polyether polyol, comprising the following steps:

[0033] a) Castor oil is mixed evenly with a bimetallic catalyst and dehydrated under vacuum. Then, propylene oxide is fed in for ring-opening polymerization. After aging and vacuum dehydration, castor oil polyether polyol prepolymer is obtained.

[0034] b) Add an acidic catalyst to the castor oil polyether polyol prepolymer obtained in step a), feed ethylene oxide to carry out a ring-opening polymerization reaction, and after aging and vacuum depolymerization, obtain the reaction solution of the castor oil polyether polyol.

[0035] c) The reaction solution obtained in step b) is filtered and separated to obtain the castor oil polyether polyol and the acid catalyst.

[0036] According to the method for preparing castor oil polyether polyol of the present invention, in step a), preferably, the amount of bimetallic catalyst used is 0.005%-0.1% of the mass of castor oil, more preferably 0.01%-0.05%.

[0037] Preferably, the bimetallic catalyst is selected from zinc hexacyanocobaltate, iron hexacyanocobaltate, aluminum hexacyanocobaltate, etc.;

[0038] Preferably, the vacuum dehydration temperature is 105-125℃; the vacuum dehydration time is 1-3 hours.

[0039] Preferably, the ring-opening polymerization reaction is carried out at a temperature of 125-165℃, more preferably 130-150℃;

[0040] Preferably, the feeding time for propylene oxide is 4-10 hours;

[0041] Preferably, the feed amount of propylene oxide is 50%-400% of the castor oil mass, and more preferably 100%-300%;

[0042] Preferably, the aging temperature is 130-160℃ and the aging time is 10-60 min;

[0043] Preferably, the vacuum desiccation time is 10-30 min; the vacuum desiccation pressure is -0.08 MPa to -0.095 MPa;

[0044] Preferably, the molecular weight of the castor oil polyether polyol prepolymer is 1500-4500, and more preferably 2000-4000.

[0045] According to the method for preparing castor oil polyether polyols of the present invention, in step b),

[0046] Preferably, the amount of acidic catalyst used is 0.5%-10% of the castor oil mass, more preferably 1%-8%;

[0047] Preferably, the ring-opening polymerization reaction is carried out at a temperature of 110-150℃;

[0048] Preferably, the feeding time for ethylene oxide is 1-3 hours;

[0049] Preferably, the feed amount of ethylene oxide is 10%-200% of the castor oil mass, and more preferably 30%-150%;

[0050] Preferably, the aging temperature is 110-150℃ and the aging time is 10-60 min;

[0051] Preferably, the vacuum de-sing time is 10-30 min; the vacuum de-sing pressure is -0.08 MPa to -0.095 MPa.

[0052] According to the method for preparing castor oil polyether polyols of the present invention, in step c),

[0053] Preferably, the filter used for filtration is a candle filter, plate and frame filter, sintered filter element filter, etc.

[0054] Preferably, the molecular weight of the castor oil polyether polyol is 3000-5000;

[0055] Preferably, the castor oil polyether polyol has a terminal primary hydroxyl content of greater than 92%, more preferably greater than 95%, and even more preferably greater than 98%.

[0056] Preferably, the separated acidic catalyst is washed with deionized water and then activated in a tubular activation furnace for reuse; preferably, the activation temperature is 600-1200℃ and the activation time is 4-10h.

[0057] The present invention also provides the use of the above-mentioned acidic catalyst in the preparation of castor oil polyether polyol, wherein the molecular weight of the castor oil polyether polyol is 3000-5000, and the content of terminal primary hydroxyl groups of the castor oil polyether polyol is greater than 92%, preferably greater than 95%, and more preferably greater than 98%.

[0058] The present invention also provides the use of the above-mentioned acidic catalyst in the manufacture of high-resilience polyurethane foam.

[0059] The present invention also provides the use of the above-mentioned castor oil polyether polyol in the manufacture of high-resilience polyurethane foam.

[0060] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0061] 1) The castor oil polyether polyol of the present invention has a high content of terminal primary hydroxyl groups (greater than 92%), strong reactivity, and small foaming shrinkage. It can replace petrochemical-based high-resilience polyether polyol and be applied to high-resilience polyurethane foam. The foam manufactured has excellent physical properties (tensile strength, tear strength, elongation at break, etc.) and high bio-based content, which is in line with the green and low-carbon development trend.

[0062] 2) This invention uses a self-made acidic catalyst, which can effectively provide protic acid and efficiently and uniformly activate epoxides, facilitating the full contact and collision reaction between ethylene oxide and castor oil polyether polyol prepolymer. This ensures that the secondary hydroxyl groups at the end of the castor oil polyether polyol prepolymer are uniformly contacted with ethylene oxide and react, which is beneficial for the conversion of secondary hydroxyl groups into primary hydroxyl groups. This increases the content of primary hydroxyl groups at the end of the prepared castor oil polyether polyol, thereby enhancing the foaming reactivity. In addition, the acidic catalyst of this invention can be recycled, which helps to reduce the cost of industrial production.

[0063] The reaction mechanism of the acidic catalyst catalyzing the ring-opening polymerization of ethylene oxide in this invention is as follows:

[0064] Detailed Implementation

[0065] Preferred embodiments of the invention will now be described in more detail. While preferred embodiments of the invention are described below, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0066] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are merely a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0067] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0068] ICP-AES tester, its test methods and conditions:

[0069] The active component NaH2PV was determined using inductively coupled plasma optical emission spectrometry (ICP-AES) with a standard curve method. x W 12-x O 40 The accurate measurement was obtained using a Thermo Scientific iCAP 6000Series ICP.

[0070] Performance testing methods for high-resilience polyurethane foam:

[0071] 1) 65% indentation hardness: Test reference GB 10807-2006

[0072] 2) Ball rebound: Test reference GB 6670-2008

[0073] 3) Tensile strength: Test reference GB 6344-2008

[0074] 4) Elongation at break: Tested according to GB 6344-2008

[0075] 5) Tear strength: Tested according to GB 10808-2006

[0076] 6) Compression set: Test reference GB 6669-2008

[0077] 7) Foam Odor Rating: Place 10g of foam in a 200ml glass bottle, tighten the cap, and then place it in an 80℃ oven for 2 hours. Have 5 people smell and rate the odor, and then take the average value as the product odor (Odor rating: 1 = no odor; 2 = slight odor; 3 = odorous, not irritating; 4 = irritating odor; 5 = strong irritating odor)

[0078] 8) Bio-based content of foam: Test reference ASTM D6866-18

[0079] The main materials used in the following embodiments and experimental examples are from the following sources:

[0080] NaH2PO4: Aladdin reagent

[0081] NaVO3: Aladdin Reagent

[0082] Na2WO4: Aladdin Reagent

[0083] Activated Carbon: Xinghua Carbon Industry Technology Co., Ltd.

[0084] DMC: Zinc hexacyanocobaltate, a bimetallic catalyst produced by Huaian Bader Company.

[0085] Castor oil: Yuci Jinhu Oil Factory (Indicators as follows: Hydroxyl value: 160-165 mgKOH / g, Acid value: ≤1 mgKOH / g, Moisture: ≤0.05%, Iodine value: 82-86 gI / 100g)

[0086] PO: Propylene oxide produced by Wanhua Chemical Co., Ltd.

[0087] EO: Ethylene oxide produced by Wanhua Chemical Co., Ltd.

[0088] Tin tetrachloride: Aladdin reagent

[0089] TDI: Toluene diisocyanate produced by Wanhua Chemical Co., Ltd.

[0090] POP2140: Polymer polyol produced by Wanhua Chemical Co., Ltd.

[0091] Polyurethane foaming aids: silicone oil B8738 (Evonik Industries), catalyst A33 (Dongguan Guangsiyuan Polyurethane Materials Co., Ltd.), T9 (Jinan Hongwang Chemical Co., Ltd.), deionized water

[0092] Unless otherwise specified, all materials in this invention are commercially available products or products that can be produced by known methods.

[0093] Example

[0094] Example 1: Preparation of acidic catalyst

[0095] Weigh 5.0 g NaH₂PO₄, 45.6 g NaVO₃, and 41.6 g Na₂WO₄, dissolve them in water, adjust the pH to 3.5 with concentrated sulfuric acid (98% by mass), stir and reflux at 60 °C for 4 h, then extract with anhydrous diethyl ether. Evaporate the aqueous layer to dryness to obtain a crystalline catalyst precursor. Characterize the mass ratio of vanadium to tungsten using ICP-AES, and determine the molecular formula to be NaH₂PV. 8.7 W 3.3 O 40 Weigh 100g of 20-40 mesh coconut shell activated carbon (C), NaH2PV 8.7 W 3.3 O 40 Dissolve 10g in 500mL of deionized water, stir and impregnate at 60℃ for 10h, then evaporate the water. Place the evaporated material in a vacuum drying oven and dry for 24h until constant weight. Place the dried material in a tube furnace and activate at 600℃ under N2 atmosphere for 5h to obtain the acidic catalyst (NaH2PV). 8.7 W 3.3 O 40 / C), seal and store for future experimental use.

[0096] Example 2: Preparation of acidic catalyst

[0097] Weigh 12.0 g NaH₂PO₄, 24.4 g NaVO₃, and 353 g Na₂WO₄, dissolve them in water, adjust the pH to 1.2 with concentrated hydrochloric acid (38% by mass), stir and reflux at 80 °C for 10 h, then extract with acetone. Evaporate the water from the aqueous layer to obtain a crystalline catalyst precursor. Characterize the mass ratio of vanadium to tungsten using ICP-AES, and determine the molecular formula to be NaH₂PV. 2.2 W 9.8 O 40 Weigh 500g of 80-100 mesh coconut shell activated carbon (C), NaH2PV 2.2 W 9.8 O 40 Dissolve 100g of the catalyst in 2000mL of deionized water, stir and soak at 80℃ for 24h, then evaporate the water. The evaporated material is then dried in a vacuum drying oven for 24h until constant weight is achieved. Finally, the dried material is placed in a tube furnace and activated at 1200℃ for 10h in a nitrogen atmosphere containing 10% (volume fraction) oxygen to obtain the acidic catalyst (NaH2PV). 2.2 W 9.8 O 40 / C), seal and store for future experimental use.

[0098] Example 3: Preparation of acidic catalyst

[0099] Weigh 5.2 g KH₂PO₄, 46.8 g KVO₃, and 43.6 g K₂WO₄, dissolve them in water, adjust the pH to 3.5 with concentrated sulfuric acid (98% by mass), stir and reflux at 60 °C for 4 h, then extract with anhydrous diethyl ether. Evaporate the aqueous layer to dryness to obtain a crystalline catalyst precursor. Characterize the mass ratio of vanadium to tungsten using ICP-AES, and determine the molecular formula as K₂WO₄. 2.2 H 1.8 PV 8.9 W 3.1 O 41 Weigh 100g of 20-40 mesh coconut shell activated carbon (C), K 2.2 H 1.8 PV 8.9 W 3.1 O 41 Dissolve 10g in 500mL of deionized water, stir and impregnate at 60℃ for 10h, then evaporate the water. Place the evaporated material in a vacuum drying oven and dry for 24h until constant weight. Then place the dried material in a tube furnace and activate at 600℃ under N2 atmosphere for 5h to obtain the acidic catalyst (K). 2.2 H 1.8 PV 8.9 W 3.1 O 41 / C), seal and store for future experimental use.

[0100] Example 4: Preparation of acidic catalyst

[0101] Weigh 6.3g K₂HPO₄, 47.6g NH₄VO₃, 40.1g K₂WO₄, and 5.6g (NH₄)₆W₇O. 24 The vanadium-tungsten catalyst precursor was dissolved in water, and the pH was adjusted to 3.5 with concentrated sulfuric acid (98% by mass). After stirring and refluxing at 60°C for 4 hours, it was extracted with anhydrous diethyl ether, and the aqueous layer was evaporated to dryness to obtain a crystalline catalyst precursor. The mass ratio of vanadium to tungsten was characterized by ICP-AES, and the molecular formula was determined to be K3H2PV. 9.2 W 2.8 O 43 Weigh 100g of 20-40 mesh coconut shell activated carbon (C), K3H2PV 9.2 W 2.8 O 43 Dissolve 10g in 500mL of deionized water, stir and impregnate at 60℃ for 10h, then evaporate the water. Place the evaporated material in a vacuum drying oven and dry for 24h until constant weight. Place the dried material in a tube furnace and activate at 600℃ under N2 atmosphere for 5h to obtain the acidic catalyst (K3H2PV). 9.2 W 2.8 O 43 / C), seal and store for future experimental use.

[0102] Example 5: Preparation of castor oil polyether polyol with high primary hydroxyl content

[0103] 933g of castor oil was mixed evenly with 0.158g of DMC, heated to 115℃ and vacuum dehydrated for 2 hours, then heated to 130℃ and fed with 1600g of PO for a total of 4 hours. The mixture was then aged at 135℃ for 1 hour, followed by vacuum dehydration at -0.090MPa for 10 minutes to synthesize castor oil polyether polyol prepolymer. 12.7g of acidic catalyst (NaH2PV) was then added to the reactor. 8.7 W 3.3 O 40 / C), heat to 130℃, feed 630g of EO, feed for 2 hours, age at 150℃ for 1 hour, vacuum de-monotropicate under -0.090MPa pressure for 10 minutes, cool to 70℃, filter through a candle filter to obtain castor oil polyether polyol with high primary hydroxyl content. The hydroxyl value was tested to be 48.5mgKOH / g, the molecular weight was 3123, and the infrared test showed that the terminal primary hydroxyl content was 95.5%.

[0104] Example 6: Preparation of castor oil polyether polyol with high primary hydroxyl content

[0105] 933g of castor oil was mixed evenly with 0.153g of DMC, heated to 125℃ and vacuum dehydrated for 1 hour, then heated to 150℃ and fed with 3150g of PO for a total of 10 hours. The mixture was then aged at 150℃ for 1 hour, followed by vacuum dehydration at -0.092MPa for 30 minutes to synthesize castor oil polyether polyol prepolymer. 64.5g of acidic catalyst (NaH2PV) was then added to the reactor. 2.2 W 9.8 O 40 / C), heat to 110℃, feed 1020g of EO, feed for 3 hours, age at 110℃ for 1 hour, vacuum de-monotropic under -0.085MPa pressure for 20 minutes, cool to 80℃, filter through a plate and frame filter to obtain castor oil polyether polyol with high primary hydroxyl content. The hydroxyl value was tested to be 30.3mgKOH / g, the molecular weight was 4999, and the infrared test showed that the terminal primary hydroxyl content was 98.6%.

[0106] Example 7: Preparation of castor oil polyether polyol with high primary hydroxyl content

[0107] 933g of castor oil was mixed evenly with 0.33g of DMC, heated to 110℃ and vacuum dehydrated for 1 hour, then heated to 140℃ and fed with 1866g of PO for a total of 8 hours. The mixture was then aged at 150℃ for 40 minutes, followed by vacuum dehydration at -0.095MPa pressure for 30 minutes to synthesize castor oil polyether polyol prepolymer. 27.99g of acidic catalyst (NaH2PV) was then added to the reactor. 2.2 W 9.8 O 40 / C), heat to 145℃, feed 1399g of EO, feed for 2 hours, age at 145℃ for 1 hour, vacuum de-monotropic under -0.092MPa pressure for 20 minutes, cool to 80℃, filter through a candle filter to obtain castor oil polyether polyol with high primary hydroxyl content. The hydroxyl value was tested to be 37.0mgKOH / g, the molecular weight was 4094, and the infrared test showed that the content of terminal primary hydroxyl groups was 99.8%.

[0108] Example 8: Preparation of castor oil polyether polyol with high primary hydroxyl content

[0109] 933g of castor oil was mixed evenly with 0.153g of DMC, heated to 105℃ and vacuum dehydrated for 3 hours, then heated to 135℃ and fed with 3150g of PO for a total of 10 hours. The mixture was then aged at 135℃ for 1 hour, followed by vacuum dehydration at -0.086MPa for 15 minutes to synthesize castor oil polyether polyol prepolymer. 64.5g of acidic catalyst (NaH2PV) was then added to the reactor. 2.2 W 9.8 O 40 / C), heat to 125℃, feed 1020g of EO, feed for 2.5h, age at 125℃ for 1h, vacuum de-monotropic under -0.093MPa pressure for 10min, cool to 80℃, filter through a plate and frame filter to obtain castor oil polyether polyol with high primary hydroxyl content. The hydroxyl value was tested to be 30.7mgKOH / g, the molecular weight was 4934, and the infrared test showed that the terminal primary hydroxyl content was 97.5%.

[0110] Example 9: Preparation of castor oil polyether polyol with high primary hydroxyl content

[0111] The synthesis process is the same as in Example 5, except that the acidic catalyst (NaH2PV) from Example 5 is used instead. 8.7 W 3.3 O 40 / C) Replace with acidic catalyst (K) 2.2 H 1.8 PV 8.9 W 3.1 O 41 / C), a castor oil polyether polyol with high primary hydroxyl content was obtained. The hydroxyl value was 49.0 mgKOH / g, the equivalent molecular weight was 3091, and the content of terminal primary hydroxyl groups was 96.5% by infrared testing.

[0112] Example 10: Preparation of castor oil polyether polyol with high primary hydroxyl content

[0113] The synthesis process is the same as in Example 5, except that the acidic catalyst (NaH2PV) from Example 5 is used instead. 8.7 W 3.3 O 40 / C) Replace with acidic catalyst (K3H2PV) 9.2 W 2.8 O 43 / C), a castor oil polyether polyol with high primary hydroxyl content was obtained. The hydroxyl value was 48.7 mgKOH / g, the equivalent molecular weight was 3110, and the content of terminal primary hydroxyl groups was 96.9% by infrared testing.

[0114] Example 11: Recycling of Acidic Catalysts

[0115] In this embodiment, the acidic catalyst obtained by filtration and separation using a plate and frame filter as described in Example 6 is used. The acidic catalyst (NaH2PV) 2.2 W 9.8 O 40 / C) After cleaning with deionized water, it was placed in a tubular activation furnace and activated at 1000℃ for 10 hours before being used again to verify the catalytic activity.

[0116] 933g of castor oil and 0.153g of DMC were mixed evenly, heated to 125℃ and vacuum dehydrated for 1 hour, then heated to 150℃ and fed with 3150g of PO for a total of 10 hours. The mixture was then aged at 150℃ for 1 hour, followed by vacuum dehydration at -0.092MPa for 30 minutes to synthesize castor oil polyether polyol prepolymer. 64.5g of acidic catalyst (NaH2PV) was then added to the reactor. 2.2 W 9.8 O 40 / C), heat to 110℃, feed 1020g of EO, feed for 3 hours, age at 110℃ for 1 hour, vacuum de-monotropic under -0.085MPa pressure for 20 minutes, cool to 80℃, filter through a candle filter to obtain castor oil polyether polyol with high primary hydroxyl content. The hydroxyl value was tested to be 30.4mgKOH / g, the molecular weight was 4982, and the infrared test showed that the terminal primary hydroxyl content was 98.7%.

[0117] Following the recycling experiment process described in Example 11, multiple recycling experiments were conducted on the acid catalyst, and the experimental data are shown in Table 1 below.

[0118] Table 1 Experimental data on multiple recycling of acidic catalysts

[0119] Loop count Product hydroxyl value (mgKOH / g) Product terminal primary hydroxyl content (%) 5 30.5 98.6 10 30.4 98.9 20 30.8 97.6 50 30.7 98.0 100 30.3 98.8

[0120] The data in Table 1 show that the acidic catalyst of the present invention can be recycled. Even after 100 cycles, castor oil polyether polyols with high primary hydroxyl content can still be obtained, which greatly helps to reduce the cost of industrial production.

[0121] Comparative Example 1: Preparation of Castor Oil Polyether Polyol

[0122] The acidic catalyst (NaH2PV) from Example 5 8.7 W 3.3 O 40 / C) Replace the same mass of tin tetrachloride (a conventional Lewis acid catalyst) with the same conditions to prepare castor oil polyether polyol. The hydroxyl value was 51.9 mg KOH / g, the molecular weight was 2918, and the content of terminal primary hydroxyl groups was 45.5% by infrared spectroscopy.

[0123] Experimental Example

[0124] Application performance testing

[0125] High-resilience polyurethane foam materials were prepared using the following components:

[0126] The component formulation of high-resilience polyurethane foam is shown in Table 2 below:

[0127] Table 2

[0128]

[0129] Note: All values ​​in the table are relative masses.

[0130] The properties of high-resilience polyurethane foam are shown in Table 3 below:

[0131] Table 3

[0132]

[0133]

[0134] As can be seen from the application examples of this invention, the castor oil polyether polyol with high primary hydroxyl content prepared by this invention can be used in high-resilience polyurethane foam. The prepared foam has a low odor and excellent physical properties (resilience, tensile strength, tear resistance, etc.). When used in high-end car seats, the foam can effectively cushion energy, improve sufficient support performance, and provide good comfort for car occupants. Furthermore, the bio-based content of the foam exceeds 10%, which is in line with the green, low-carbon, and healthy development trend and has good application value.

Claims

1. A method for preparing a castor oil polyether polyol, comprising the following steps: a) uniformly mixing castor oil with a double metal catalyst, vacuum dehydrating, and then feeding propylene oxide for ring-opening polymerization, aging, vacuum dehydrating, to obtain a castor oil polyether polyol prepolymer; b) adding ethylene oxide to the castor oil polyether polyol prepolymer obtained in step a) for ring-opening polymerization, aging, vacuum dehydrating, to obtain a castor oil polyether polyol; and c) filtering and separating the reaction solution obtained in step b) to obtain the castor oil polyether polyol and the acidic catalyst. In step a), b) adding an acidic catalyst to the castor oil polyether polyol prepolymer obtained in step a), feeding in ethylene oxide to carry out ring-opening polymerization, aging, and vacuum singling to obtain a reaction solution of the castor oil polyether polyol; wherein the acidic catalyst is a metal catalyst supported by activated carbon, and the molecular formula is M a H b PV x W 12-x O d / C, wherein M is an alkali metal or an alkaline earth metal, 1≤a≤3, 1≤b≤2, 40≤d≤45, and 2≤x≤10; the amount of the double metal catalyst is 0.005%-0.1% of the mass of the castor oil; and / or 2. The process for the preparation of castor oil polyether polyol as claimed in claim 1 wherein, the double metal catalyst is selected from zinc hexacyanocobaltate, iron hexacyanocobaltate, and / or aluminum hexacyanocobaltate; and / or the temperature for vacuum dehydrating is 105-125℃; the time for vacuum dehydrating is 1-3h; and / or the temperature for ring-opening polymerization is 125-165℃; and / or the feeding time for propylene oxide is 4-10h; and / or the feeding amount of propylene oxide is 50%-400% of the mass of the castor oil; and / or the aging temperature is 130-160℃, and the aging time is 10-60min; and / or the time for vacuum dehydrating is 10-30min; the pressure for vacuum dehydrating is-0.08MPa to-0.095MPa; and / or the molecular weight of the castor oil polyether polyol prepolymer is 1500-4500. In step b), the amount of the acidic catalyst is 0.5%-10% of the mass of the castor oil; and / or 3. The process for the preparation of castor oil polyether polyol according to claim 1 or 2, wherein, the temperature for ring-opening polymerization is 110-150℃; and / or the feeding time for ethylene oxide is 1-3h; and / or the feeding amount of ethylene oxide is 10%-200% of the mass of the castor oil; and / or the aging temperature is 110-150℃, and the aging time is 10-60min; and / or the time for vacuum dehydrating is 10-30min; the pressure for vacuum dehydrating is-0.08MPa to-0.095MPa. In step c), the filter used for filtering is a candle filter, a plate-and-frame filter, or a sintered filter element filter; and / or 4. The process for the preparation of castor oil polyether polyol according to claim 1 or 2, wherein, the molecular weight of the castor oil polyether polyol is 3000-5000; and / or the content of terminal primary hydroxyl groups in the castor oil polyether polyol is greater than 92%; and / or the separated acidic catalyst is washed with deionized water, and then is activated in a tubular activation furnace for reuse; the activation temperature is 600-1200℃; and the activation time is 4-10h. In the acidic catalyst, M is selected from sodium or potassium. The method for preparing the acidic catalyst comprises the following steps:

5. The process for preparing castor oil polyether polyol according to claim 1, wherein, wherein M is an alkali metal or an alkaline earth metal, 1≤a≤3, 1≤b≤2, 40≤d≤45, and 2≤x≤10; the molar ratio of the soluble phosphate salt to the soluble vanadium salt is 1:2-10; the molar ratio of the soluble vanadium salt to the soluble tungsten salt is 1:0.2-6; and the amount of the activated carbon is 100%-2000% of the mass of the catalyst precursor.

6. The process for preparing castor oil polyether polyol according to claim 1, wherein, In step 1) of the method for preparing the acidic catalyst, 1) Synthesis of catalyst precursor: soluble phosphate, soluble vanadium salt, soluble tungsten salt are added into water, heated and stirred under acidic condition, after reaction, cooled, extracted, dried, to obtain catalyst precursor, molecular formula is M a H b PV x W 12-x O d ; 2) activated carbon support: activated carbon, catalyst precursor is added into water, stirring impregnation, impregnation after steam dry water, dry, dry activated, the molecular formula of the acid catalyst is M a H b PV x W 12-x O d / C; M is selected from sodium or potassium; and / or 7. The process for the preparation of castor oil polyether polyol as claimed in claim 6 wherein, the acidic condition is adjusted by an acidic adjuster, wherein the acidic adjuster is concentrated sulfuric acid, concentrated nitric acid, and / or concentrated hydrochloric acid; the pH range of the acidic condition is pH 1-5; and / or the reaction temperature is 40-80℃; the reaction time is 1-10h; and / or The soluble phosphate salt is selected from one or more of NaH2PO4, Na2HPO4, KH2PO4, K2HPO4, the soluble vanadium salt is selected from one or more of NaVO3, KVO3, NH4VO3, the soluble tungsten salt is selected from one or more of Na2WO4, K2WO4, (NH4)6W7O 24 ; and / or the reaction temperature is 40-80℃; the reaction time is 1-10h; and / or ​ The solvent used for extraction is acetone, diethyl ether and / or n-hexane.

8. The process for the preparation of castor oil polyether polyol according to claim 6 or 7, wherein, In step 2) of the preparation method of the acid catalyst, The activated carbon is selected from coconut shell activated carbon, peanut shell activated carbon and / or walnut shell activated carbon, and the mesh number of the activated carbon is 20-100 mesh; and / or The temperature of stirring impregnation is 60-90℃; the time of stirring impregnation is 10-24h; and / or The activation is carried out under a nitrogen atmosphere, or under a nitrogen atmosphere containing 1-10% oxygen; and / or The activation temperature is 600-1200℃; the activation time is 4-10h.

9. A castor oil polyether polyol prepared according to the preparation method of any one of claims 1-4, having the following structural formula: wherein, m = 20-60, n = 20-40; The content of terminal primary hydroxyl groups of the castor oil polyether polyol is greater than 92%.

10. The castor oil polyether polyol of claim 9, wherein, The molecular weight of the castor oil polyether polyol is 3000-5000, and the content of terminal primary hydroxyl groups of the castor oil polyether polyol is greater than 95%.

11. Use of an acidic catalyst in the preparation of a castor oil polyether polyol, wherein, The acid catalyst is as defined in claim 1, the molecular weight of the castor oil polyether polyol is 3000-5000, and the content of terminal primary hydroxyl groups of the castor oil polyether polyol is greater than 92%.

12. The use according to claim 11, wherein, The content of terminal primary hydroxyl groups of the castor oil polyether polyol is greater than 95%.

13. Use according to claim 12, wherein, The content of terminal primary hydroxyl groups of the castor oil polyether polyol is greater than 98%.

14. Use of an acidic catalyst in the manufacture of high resilience polyurethane foam, wherein, The acid catalyst is as defined in claim 1.

15. Use of the castor oil polyether polyol of claim 9 or 10, or the castor oil polyether polyol prepared according to the preparation method of any one of claims 1-8, in the manufacture of high resilience polyurethane foam.

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