Preparation method of aliphatic chain group polyol

Abstract

The invention relates to a preparation method of aliphatic chain based polyol, which takes epoxidized vegetable oil as a raw material, and comprises the following steps in sequence: step 1), the epoxidized vegetable oil is converted into a high-functionality mixture S containing an aliphatic chain monoester compound after ring-opening reaction and ester exchange reaction, the number-average molecular weight of the mixture S is less than 550, and the average functionality is greater than or equal to 3; and 2) carrying out ring-opening polymerization reaction on the high-functionality mixture S containing the aliphatic chain monoester compound and oxyalkylene to obtain the aliphatic chain based polyol. The bio-based polyether polyol has the comprehensive advantages that the bio-based polyether polyol with good compatibility with petroleum-based polyether is prepared, the bio-based polyether polyol can be used for improving the bio-based proportion of a rigid polyurethane foam material, and the rigid polyurethane foam material can still have good specific strength under the condition that the dosage is high.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical synthesis, and specifically relates to a method for preparing a fatty chain-based polyol. Background Art

[0002] Polyol is one of the main raw materials required for polyurethane materials. At present, petroleum-based polyol raw materials are mainly used in the field of rigid foam. Polyol compounds can also be prepared with vegetable oil as raw materials, which can reduce the dependence and consumption of petrochemical resources and help reduce carbon emissions. According to the type of vegetable oil and its preparation process, the structure and composition of the obtained polyol compounds are also different, such as fatty chain-based polyols containing fatty chain segment structures, etc., which can also be divided into single fatty chain-based polyols, double fatty chain-based polyols and multi-fatty chain-based polyols according to the amount of fatty chains contained in a single molecule. Although vegetable oil has good energy-saving and environmental protection properties, the physicochemical properties of the obtained polyols still have some defects, which in turn affect their application in the field of polyurethane rigid foam. For example, vegetable oil-based polyols can usually give materials good flexibility, but it is difficult to meet high strength requirements and has poor compatibility with petroleum-based polyols.

[0003] CN101314632A discloses a method for preparing rigid polyurethane foam plastics using soybean oil, wherein the method uses epoxidized soybean oil as a raw material to obtain soybean oil-based polyols through ring-opening reaction and alcoholysis reaction. However, when the soybean oil-based polyols are used in an amount of 100%, the specific strength of the obtained rigid polyurethane foam is low. In order to solve this problem, an esterification step is added, that is, the soybean oil-based polyols are subjected to esterification reaction with organic acids and acid anhydrides to generate soybean oil-based polyester polyols to improve the hardness of the polymer. However, this process increases the complexity of the process, and the viscosity of the polyester polyols is relatively large, which is not conducive to the flow of materials.

[0004] CN1844183A discloses a rigid polyurethane foam plastic prepared from rapeseed oil, which first prepares bio-based polyols and then uses them in combination with petroleum-based polyether polyols to improve specific strength. However, the amount of petroleum-based polyether polyols used is ≥70%, and the compatibility of petroleum-based polyether polyols with bio-based polyols is poor, making it difficult to increase the proportion of bio-based polyols used.

[0005] Therefore, in order to promote the application of vegetable oil-based polyols in the field of polyurethane rigid foams and promote the development of low-carbon and environmentally friendly polyurethane rigid foams, there is an urgent need for a vegetable oil-based polyol that can take into account both specific strength and material compatibility. Summary of the invention

[0006] The object of the present invention is to provide a vegetable oil-based polyol having good compatibility with a petroleum-based polyether polyol, which can provide a rigid polyurethane foam with good specific strength while using a high amount of the vegetable oil-based polyol.

[0007] In order to achieve the above object, the present invention specifically adopts the following technical solutions:

[0008] A method for preparing a fatty chain-based polyol, using epoxidized vegetable oil as a raw material, comprises the following steps in sequence:

[0009] Step 1), converting the epoxidized vegetable oil into a high-functionality mixture S containing fatty chain monoester compounds through a ring-opening reaction and an ester exchange reaction, wherein the number average molecular weight of the mixture S is less than 550 and the average functionality is greater than or equal to 3;

[0010] Step 2) The high-functionality mixture S containing fatty chain monoester compounds is subjected to a ring-opening polymerization reaction with an oxidized olefin to obtain a fatty chain-based polyol.

[0011] The above method first obtains a monoester compound with a specific molecular weight and functionality, and then uses the monoester compound as one of the components of the initiator to prepare a fatty chain-based polyol. The fatty chain-based polyol of the present invention is a compound containing a fatty chain segment in the molecular structure of the polyol, and the length of the fatty chain segment can be divided into: a short fatty chain with a carbon atom number of less than 6, a medium fatty chain with a carbon atom number of 6 to 12, and a long fatty chain with a carbon atom number of more than 12 according to the number of carbon atoms. The fatty chain segment of the fatty chain-based polyol obtained by the preparation method of the present invention comes from triglyceride fatty acid esters in the raw material vegetable oil, that is, one fatty acid ester molecular structure contains three fatty chain segments, and the length of a single fatty chain segment is usually ≥12 carbon atoms, such as 12 to 24. The present invention refers to a compound containing only one fatty chain segment in a single molecule as a fatty chain monoester compound. The applicant has found through research that, compared with the structure containing three fatty chain segments in a single molecule, the fatty chain monoester compound is conducive to improving the compatibility with petroleum-based polyether polyols and the specific strength of polyurethane foams, and when the number average molecular weight of the mixture S is less than 550 and the average functionality is ≥3, the obtained fatty chain polyol has a significant effect on improving the foam specific strength. And after the mixture S is further subjected to the ring-opening polymerization reaction with oxidized olefins in step 2), the compatibility of the obtained fatty chain polyol with petroleum-based polyether polyols is improved, and it can be matched with petroleum-based polyether polyols in any proportion, so that a higher specific strength can be taken into account at the same time when the proportion of fatty chain polyols is higher.

[0012] The mixture S of the present invention is the reaction product obtained after the ring-opening reaction and the transesterification reaction of the epoxidized vegetable oil. The ring-opening reaction is the reaction of the epoxy bond in the epoxidized vegetable oil opening and converting it into a hydroxyl group. The transesterification reaction is the reaction of alcohol and ester exchange to form a new alcohol and a new ester. The order of the ring-opening reaction and the transesterification reaction in step 1) of the present invention is not limited. The epoxidized vegetable oil can be subjected to the ring-opening reaction first and then the reaction product can be subjected to the transesterification reaction. The epoxidized vegetable oil can also be subjected to the transesterification reaction first and then the reaction product can be subjected to the ring-opening reaction. Alternatively, the ring-opening reaction and the transesterification reaction can be carried out simultaneously or alternately. The mixture S prepared by the present invention is a compound rich in hydroxyl groups, so the average functionality is the average functionality of hydroxyl groups. The specific composition of the mixture S varies depending on the reaction product. However, the applicant has found through research that the problem of improving the specific strength of the present invention can be solved as long as the number average molecular weight of the mixture S is less than 550 and the average functionality is ≥ 3. At the same time, in order to further take into account the moderate viscosity of the obtained fatty chain-based polyol, the number average molecular weight of the mixture S is preferably 310-520 and the average functionality is 3-6.

[0013] Since step 1) of the present invention includes the process of converting a fatty chain polyester compound into a fatty chain monoester compound, the mixture S obtained in step 1) of the present invention includes a fatty chain monoester compound, unreacted fatty chain diester compound, unreacted fatty chain triester compound, unreacted hydroxyl compound, etc. In order to take into account both the specific strength and the higher solubility in alkane physical foaming agents, it is preferred that the mass proportion of the fatty chain monoester compound is greater than 85%, such as 88-100%, the mass proportion of the fatty chain diester compound is less than 0.5%, such as 0-0.4%, and the mass proportion of the fatty chain triester compound is less than 15%, such as 0-12%.

[0014] The epoxidized vegetable oil described in the present invention can be any conventional one in the art, such as at least one of epoxidized soybean oil, epoxidized rapeseed oil, epoxidized castor oil, epoxidized tung oil, epoxidized cottonseed oil, epoxidized olive oil, epoxidized peanut oil, epoxidized coconut oil, epoxidized palm oil, epoxidized sesame oil, epoxidized sunflower seed oil, epoxidized linseed oil, epoxidized tung oil, epoxidized rice bran oil, and epoxidized corn oil.

[0015] The ring-opening reaction of the present invention is carried out under the action of a solid acid catalyst at a reaction temperature of 40 to 130°C, the transesterification reaction is carried out under the action of an acidic catalyst and / or a basic catalyst at a reaction temperature of 40 to 250°C, and the ring-opening polymerization reaction temperature is 70 to 160°C.

[0016] Furthermore, when a solid acid catalyst is used as an acidic catalyst in the transesterification reaction, it is preferred to use the solid acid catalyst in combination with a quaternary ammonium salt phase transfer catalyst to reduce the adverse effects of water on the transesterification reaction. The quaternary ammonium salt phase transfer catalyst can be selected from at least one of tetrabutylammonium bromide, tetrabutylammonium chloride, trimethylbenzylammonium chloride, trioctylmethylammonium chloride, dodecyltrimethylammonium chloride, hexadecyltrimethylammonium bromide, triethylbenzylammonium chloride, tetrabutylammonium hydrogen sulfate or benzyltriethylammonium chloride. The amount of the solid acid catalyst is usually 3 to 15% of the total mass of the epoxidized vegetable oil. The amount of the quaternary ammonium salt phase transfer catalyst is usually 0.05% to 0.5% of the total mass of the epoxidized vegetable oil.

[0017] Further, in order to reduce the consumption of the alkaline catalyst in the subsequent transesterification reaction by the residual acidic substance, while taking into account the ring-opening efficiency of the epoxidized vegetable oil, the solid acid catalyst is preferably a heteropolyacid salt, such as a phosphotungstic heteropolyacid salt catalyst, having the structural formula [(C n H 2n+1 )N(CH3)3]3PW4O 16 , where n=10~18.

[0018] Step 2) of the present invention is a ring-opening polymerization reaction with the mixture S as an initiator and an oxidized olefin. The oxidized olefin can be conventional in the art, such as at least one of ethylene oxide, propylene oxide, and butylene oxide. The ring-opening polymerization reaction is preferably carried out under the action of a basic catalyst. The basic catalyst can be the alkaline substance remaining in the ester exchange reaction in step 1 of the present invention, or it can be an additional alkaline substance added according to the reaction process, so that the ring-opening polymerization reaction can proceed smoothly. The basic catalyst that can be used for the ring-opening polymerization reaction can be selected from oxides, hydroxides, alcoholates, inorganic salts, etc. of alkali metals and / or alkaline earth metals, wherein alkali metal hydroxides include but are not limited to sodium hydroxide, potassium hydroxide, lithium hydroxide, rubidium hydroxide, cesium hydroxide, etc.; alkali metal alcoholates include but are not limited to potassium methoxide, sodium methoxide, sodium ethoxide, sodium tert-butoxide, potassium tert-butoxide, etc.; alkaline earth metal hydroxides include but are not limited to calcium hydroxide, barium hydroxide, magnesium hydroxide, strontium hydroxide, etc.; alkaline earth metal oxides include but are not limited to magnesium oxide, calcium oxide, barium oxide, etc.; alkali metal inorganic salts include but are not limited to sodium carbonate, potassium carbonate, etc. It is preferred that the alkaline catalyst of the transesterification reaction is the same as the alkaline catalyst of the ring-opening polymerization reaction, so as to simplify the preparation process steps. The material ratio of the mixture S and the oxidized olefins described in the present invention can be conventional in the art, usually determined according to the purpose of use. For example, in the field of rigid polyurethane foam, the hydroxyl value of the polyether polyol is usually required to be greater than 300 mgKOH / g, and the theoretical material ratio can be calculated by the target hydroxyl value. In order to obtain rigid polyurethane foam with excellent comprehensive performance, the hydroxyl value of the obtained fatty chain polyol is preferably 350-550 mgKOH / g. The fatty chain polyol obtained after the ring-opening polymerization reaction is usually a crude product. In order to prevent the negative impact of by-products on the polyurethane foaming reaction, the crude product can usually be further refined. The refining treatment can be carried out by conventional methods in the art, such as removing water, alkali metal and / or alkaline earth metal ions, impurities, etc. after neutralization and adsorption treatment to obtain a refined fatty chain polyol product.

[0019] There are many ways to obtain the mixture S of the present invention, and the present invention prefers the first and second ways.

[0020] Among them, the route one, i.e., the step 1), sequentially comprises a first step of generating a low-functionality monoester compound and a second step of generating a high-functionality mixture S, wherein the average functionality of the low-functionality monoester compound is less than 3, the first step is a ring-opening reaction and an ester exchange reaction between the epoxidized vegetable oil and the second hydroxy compound under the action of a solid acid catalyst and a quaternary ammonium salt phase transfer catalyst, and after the reaction, a mixture D containing a low-functionality monoester compound is obtained, the second hydroxy compound is a mixture of water and a monohydric alcohol, and the second step is to perform an ester exchange reaction between the mixture D and the first hydroxy compound under the action of an alkaline catalyst to obtain the high-functionality mixture S containing the fatty chain monoester compound. The route one of the present invention first prepares a low-functionality monoester compound, and the low-functionality monoester compound can undergo an ester exchange reaction with the first hydroxy compound under relatively low temperature conditions, which is beneficial to energy saving and consumption reduction, and the ester exchange reaction efficiency is high, and the proportion of fatty chain monoester compounds in the obtained mixture S is relatively high.

[0021] Wherein, the monohydric alcohol is at least one of methanol, ethanol, propanol and butanol. In order to obtain better transesterification efficiency, the molar amount of water is preferably 0.6 to 1.3 times the molar amount of epoxy groups, and the molar amount of the monohydric alcohol is preferably 1.0 to 5.0 times the molar amount of epoxy groups. Furthermore, the molar ratio of water to the monohydric alcohol is preferably <1.

[0022] In order to take into account the high functionality and low viscosity of the fatty chain polyol, and to further take into account the material fluidity and crosslinking density, the functionality of the first hydroxyl compound is preferably ≥ 3 and the molecular weight is < 350. Taking into account the availability of raw materials, at least one of glycerol, trimethylolpropane, polyglycerol, pentaerythritol, sorbitol, and sucrose can be selected.

[0023] Furthermore, in order to take into account both the reaction efficiency and the optimization effect on foam performance, the first hydroxy compound is preferably in an excess state in the transesterification reaction, that is, the molar ratio of the first hydroxy compound to the ester compound is ≥1, such as (1-20):1.

[0024] More specifically, taking a solid acid catalyst as an example, the method for preparing a fatty chain-based polyol using route 1 of the present invention comprises the following sequential steps:

[0025] (1) adding epoxidized vegetable oil, a second hydroxy compound, a solid acid catalyst and a quaternary ammonium salt phase transfer catalyst into a reactor, performing ring-opening and transesterification reactions at 81 to 130° C., cooling and filtering after the reaction is completed, and removing unreacted second hydroxy compound and small molecular substances from the filtrate under vacuum conditions to obtain a mixture D containing a low-functionality monoester compound;

[0026] (2) adding the mixture D, the first hydroxy compound and the alkaline catalyst into a reactor, and performing an ester exchange reaction at 40 to 80° C., and obtaining the mixture S after the reaction, wherein the molar ratio of the first hydroxy compound to the mixture D is (1 to 10):1;

[0027] (3) adding olefin oxide to the mixture S, carrying out a ring-opening polymerization reaction at 70 to 160° C. and a gauge pressure of 0 to 1.0 MPa under the action of an alkaline catalyst, aging, removing small molecular substances, and obtaining a crude fatty chain polyol product;

[0028] (4) The crude product is purified to obtain refined fatty chain polyol.

[0029] The small molecule substances described in the present invention are mainly water and / or alcohols, aldehydes, ethers, esters and other substances with carbon atoms less than 5.

[0030] The second approach, i.e., step 1), comprises a first process of ring-opening the epoxidized vegetable oil with a third hydroxy compound under the action of a solid acid catalyst to generate a hydroxyl group, and a process of transesterifying the fatty acid ester group with the first hydroxy compound under the action of a basic catalyst to form the high-functionality mixture S, wherein the functionality of the third hydroxy compound is ≤3 and the molecular weight is <150. This approach first performs a simple ring-opening reaction, which can obtain a higher ring-opening efficiency.

[0031] Among them, the third hydroxy compound preferably has an average functionality of 2, and can be selected from at least one of water, ethylene glycol, propylene glycol, diethylene glycol, and dipropylene glycol. The molar ratio of the third hydroxy compound to the epoxy group is (1-4): 1. The type, dosage ratio, and effect of the first hydroxy compound are the same as those of approach one.

[0032] Taking a solid acid catalyst as an example, the preparation method of a fatty chain-based polyol using route 2 of the present invention comprises the following steps in sequence:

[0033] (1) adding epoxidized vegetable oil, a third hydroxy compound and a solid acid catalyst into a reactor, and performing a ring-opening reaction at 40 to 80° C., cooling and filtering after the reaction is completed, and removing the unreacted third hydroxy compound and small molecular substances from the filtrate under vacuum conditions to obtain a hydroxylated polyester compound E;

[0034] (2) adding the hydroxylated polyester compound E, the first hydroxy compound and the alkaline catalyst into a reactor, and performing an ester exchange reaction at 130 to 250° C., and obtaining the mixture S after the reaction, wherein the molar ratio of the first hydroxy compound to the hydroxylated polyester compound E is (5 to 20):1;

[0035] (3) adding olefin oxide to the mixture S, carrying out a ring-opening polymerization reaction at 70 to 160° C. and a gauge pressure of 0 to 1.0 MPa under the action of an alkaline catalyst, aging, removing small molecular substances, and obtaining a crude fatty chain polyol product;

[0036] (4) The crude product is purified to obtain refined fatty chain polyol.

[0037] In general, the comprehensive advantages of this application are: a bio-based polyether polyol with good compatibility with petroleum-based polyether is produced, which can be used to increase the bio-based proportion of rigid polyurethane foam materials, and can still take into account good specific strength when used in higher amounts. DETAILED DESCRIPTION

[0038] In order to better understand the present invention, the content of the present invention is further explained below in conjunction with the embodiments, but the content of the present invention is not limited to the following embodiments.

[0039] The epoxidized vegetable oil used in the embodiment of the present invention is as follows:

[0040] Epoxidized soybean oil, epoxide value 6.8 mol / 100 g, fatty chain triester compound content 98.1 wt%, fatty chain diester compound content 1.4 wt%, fatty chain monoester compound content 0.5 wt%, homemade;

[0041] Epoxidized corn oil, epoxide value 6.0 mol / 100 g, fatty chain triester compound content 96.4 wt%, fatty chain diester compound content 2.9 wt%, fatty chain monoester compound content 0.7 wt%, homemade;

[0042] Epoxidized linseed oil, epoxide value 7.8 mol / 100 g, fatty chain triester compound content 91.1 wt%, fatty chain diester compound content 5.1 wt%, fatty chain monoester compound content 3.8 wt%, homemade;

[0043] Epoxidized rapeseed oil, epoxide value 5.2 mol / 100 g, fatty chain triester compound content 95.7 wt%, fatty chain diester compound content 3.8 wt%, fatty chain monoester compound content 0.5 wt%, homemade;

[0044] Epoxidized cottonseed oil, epoxide value 6.2 mol / 100 g, fatty chain triester compound content 93.9 wt%, fatty chain diester compound content 5.0 wt%, fatty chain monoester compound content 1.1 wt%, homemade;

[0045] The epoxidized vegetable oil is prepared by the following method: vegetable oil, 99wt% acetic acid solution and 98wt% sulfuric acid solution are added into a reaction container in a mass ratio of 1:0.24:0.02, 50wt% hydrogen peroxide is slowly added at 40°C, the amount of hydrogen peroxide added is 50wt% of the total amount of vegetable oil, the reaction temperature is maintained at 50-70°C, after the reaction is completed, the mixture is allowed to stand and cool to separate into layers, the lower layer of acid aqueous solution is separated, 5wt% NaOH solution is added to the oil layer to neutralize it to a pH of about 6-7, and then the mixture is washed with a saturated sodium chloride solution at 50-60°C and pure water, dehydrated under reduced pressure, and filtered to obtain the epoxidized vegetable oil.

[0046] The solid acid catalyst used in the embodiment of the present invention is as follows: Cat1#, with a structural formula of [(C 10 H 21 )N(CH3)3]3PW4O 16 , homemade; Cat2#, structural formula is [(C 14 H 29 )N(CH3)3]3PW4O 16 , self-made; Cat3#, structural formula is [(C 16 H 33 )N(CH3)3]3PW4O 16 , self-made; Cat4#, structural formula is [(C 18 H 37 )N(CH3)3]3PW4O 16 ,self made;

[0047] Cat5#, sulfuric acid modified montmorillonite, MMT-H2SO4, homemade.

[0048] The heteropoly acid salt type solid acid catalyst is prepared by the following method: tungstic acid and 30wt% hydrogen peroxide solution are added to a round-bottom flask in a mass ratio of 1:2.5, respectively, and stirred at 60°C. After the reaction is completed, the solution is cooled to room temperature, and then 85wt% phosphoric acid solution of 3.0wt% of the total material is added, and after stirring evenly, an ethanol solution of C10-C18 alkyltrimethylammonium chloride is slowly added dropwise to the above reaction solution in a phosphorus-nitrogen molar ratio of 1:1, and stirred at 20-40°C for 1-2h. After the reaction is completed, a white powder is obtained by filtering, and the obtained powder is washed with water, washed with alcohol, and dried in sequence to obtain a solid acid catalyst having the structural formula [(C n H 2n+1 )N(CH3)3]3PW4O 16 , where n=10~18.

[0049] The sulfuric acid-modified montmorillonite solid acid catalyst was prepared by the following method: sodium montmorillonite and 0.5 mol / L sulfuric acid solution were mixed in a mass ratio of 1:12, stirred at 50°C for 24 hours, cooled to room temperature and filtered, washed with water and dried to obtain a solid catalyst powder.

[0050] The epoxy ring opening rate of the present invention, i.e., the rate of change of the epoxy value, is calculated by the formula: [(raw material epoxy value-product epoxy value) / raw material epoxy value]×100%, and the epoxy value is determined according to the method of "Determination of Epoxy Value of Plasticizers GB / T 1677-2023";

[0051] The type and content of fatty acid esters of the present invention are detected by liquid chromatography, and the specific method is as follows: the liquid chromatography column is a C18 column, the column temperature is 50°C, the mobile phase used for the analysis of saturated fatty acid glycerides is anhydrous ethanol, the mobile phase used for the analysis of unsaturated fatty acid glycerides is methanol, the mobile phase for high-functionality fatty acid esters is methanol and water, and the solvent is tetrahydrofuran. The sample to be tested is added to the mobile phase and the solvent, ultrasonically oscillated at about 60°C, and after the sample is completely dissolved, the sample is sampled and analyzed while hot, and the quantitative calculation is normalized by area addition.

[0052] The crude product refining process of the fatty chain polyol adopted in the embodiment of the present invention is as follows: pure water and 20wt% to 60wt% phosphoric acid solution are added to the crude product, the pH is adjusted to 5.0 to 6.5, and then 0.1 to 5wt% of magnesium silicate is added for adsorption. After the adsorption is completed, vacuum dehydration is performed at 80 to 120° C., and filtration is performed to obtain a refined product.

[0053] The implementation method of the first approach of the present invention is as follows: Example 1 to Example 5

[0054] Example 1

[0055] (1) Preparation of mixture S: epoxidized soybean oil, a second hydroxyl compound (water and methanol), a solid acid catalyst Cat4# and tetrabutylammonium bromide are added to a reactor, wherein the molar amount of water is 0.6 times the molar amount of the epoxy group, the molar amount of methanol is 1.4 times the molar amount of the epoxy group, the amount of Cat4# used is 3% of the mass of the epoxidized soybean oil, and the amount of tetrabutylammonium bromide used is 0.2% of the mass of the epoxidized soybean oil. Ring-opening and transesterification reactions are carried out at 110° C. After the reaction is completed, the mixture is cooled and filtered, and the unreacted second hydroxyl compound and small molecular substances are removed from the filtrate under vacuum conditions to obtain a mixture D-1# containing a low-functionality monoester compound. After testing, the ring-opening rate of the ring-opening reaction is 99.0%, the epoxy value of the mixture D-1# is 0.068 mol / 100 g, the average functionality is 1.8, and the proportion of fatty chain monoester compounds is 100%;

[0056] Add mixture D-1#, the first hydroxy compound (a mixture of glycerol and sucrose in a mass ratio of 7:3) and alkaline catalyst potassium hydroxide into a reactor, wherein the molar ratio of the first hydroxy compound to mixture D-1# is 1:1, and the amount of potassium hydroxide used is 0.5% of the total mass of mixture D-1#. An ester exchange reaction is carried out at 80°C. After the reaction, a mixture S-1# containing fatty chain monoester compounds is obtained. After testing, the fatty chain monoester compounds in the mixture S-1# account for 100wt%, the fatty chain diester compounds account for 0, the fatty chain triester compounds account for 0, the number average molecular weight is 471, and the average functionality is 4.5.

[0057] (2) Preparation of fatty chain polyols: Propylene oxide was introduced into the reactor at a molar ratio of 3:1 to the mixture S-1#. At the same time, 0.5% potassium hydroxide was added based on the mass of the mixture S-1#. Ring-opening polymerization was carried out at 100°C and a gauge pressure of 0.8 MPa. After the reaction was completed, the crude fatty chain polyol was aged and small molecular compounds were removed to obtain a fatty chain polyol. After refining, a fatty chain polyol B-1# was obtained. After testing, the fatty chain monoester compound of B-1# accounted for 100wt%, the fatty chain diester compound accounted for 0%, the fatty chain triester compound accounted for 0, the average hydroxyl value was 380mgKOH / g, and the average functionality was 4.4.

[0058] Example 2

[0059] (1) Preparation of mixture S: epoxidized corn oil, a second hydroxyl compound (water and ethanol), a solid acid catalyst Cat5# and benzyltriethylammonium chloride are added to a reactor, wherein the molar amount of water is 1.0 times the molar amount of the epoxy group, the molar amount of ethanol is 3.0 times the molar amount of the epoxy group, the amount of Cat5# used is 5% of the mass of the epoxidized vegetable oil, and the amount of benzyltriethylammonium chloride used is 0.08% of the mass of the epoxidized vegetable oil. Ring-opening and transesterification reactions are carried out at 130° C. After the reaction is completed, the mixture is cooled and filtered, and the unreacted second hydroxyl compound and small molecular substances are removed from the filtrate under vacuum conditions to obtain a mixture D-2# containing a low-functionality monoester compound. After testing, the ring-opening rate of the ring-opening reaction is 98.4%, the epoxy value of the mixture D-2# is 0.096 mol / 100 g, the average functionality is 2.6, the proportion of fatty chain monoester compounds is 99wt%, the proportion of fatty chain diester compounds is 0.03wt%, and the proportion of fatty chain triester compounds is 0.97wt%;

[0060] Add mixture D-2#, the first hydroxy compound (trimethylolpropane) and the alkaline catalyst sodium ethoxide into the reactor, wherein the molar ratio of the first hydroxy compound to mixture D-2# is 3:1, and the amount of sodium ethoxide is 1.0% of the total mass of mixture D-2#. Perform ester exchange reaction at 60°C, and obtain mixture S-2# containing fatty chain monoester compounds after completion of the reaction. According to the testing, the fatty chain monoester compounds, the fatty chain diester compounds, and the fatty chain triester compounds in mixture S-2# account for 99wt%, 0.03wt%, and 0.97wt%, respectively. The number average molecular weight is 321, and the average functionality is 3.2.

[0061] (2) Preparation of fatty chain polyols: Propylene oxide and ethylene oxide were introduced into a reactor at a molar ratio of 1.4:1 to the mixture S-2#, and a ring-opening polymerization reaction was carried out at 110°C and a gauge pressure of 0.6 MPa. After the reaction was completed, the crude fatty chain polyol was aged and small molecular compounds were removed to obtain a fatty chain polyol. After refining, a fatty chain polyol B-2# was obtained. After testing, the fatty chain monoester compound of B-2# accounted for 99wt%, the fatty chain diester compound accounted for 0.03wt%, the fatty chain triester compound accounted for 0.97wt%, the average hydroxyl value was 451mgKOH / g, and the average functionality was 3.2.

[0062] Example 3

[0063] (1) Preparation of mixture S: epoxidized linseed oil, a second hydroxy compound (water, methanol and propanol), a solid acid catalyst Cat3# and hexadecyltrimethylammonium bromide are added to a reactor, wherein the molar amount of water is 1.3 times the molar amount of epoxy groups, the molar amount of methanol is 1.0 times the molar amount of epoxy groups, the molar amount of propanol is 1.0 times the molar amount of epoxy groups, the amount of Cat3# is 8% of the mass of the epoxidized vegetable oil, and the amount of hexadecyltrimethylammonium bromide is 0.1% of the mass of the epoxidized vegetable oil. The mixture is heated at 81°C. Ring and ester exchange reaction, after the reaction is completed, cooling and filtering, removing the unreacted second hydroxyl compound and small molecular substances from the filtrate under vacuum conditions, to obtain a mixture D-3# containing a low-functionality monoester compound. After testing, the ring opening rate of the ring opening reaction is 99.5%, the epoxy value of the mixture D-3# is 0.039 mol / 100g, the average functionality is 2.4, the fatty chain monoester compound accounts for 98wt%, the fatty chain diester compound accounts for 0.1wt%, and the fatty chain triester compound accounts for 1.9wt%;

[0064] Add mixture D-3#, the first hydroxy compound (glycerol) and the alkaline catalyst sodium methoxide into the reactor, wherein the molar ratio of the first hydroxy compound to mixture D-3# is 7:1, and the amount of sodium methoxide is 2.0% of the total mass of mixture D-3#. Perform ester exchange reaction at 50°C, and obtain mixture S-3# containing fatty chain monoester compounds after completion of the reaction. After testing, the fatty chain monoester compounds, the fatty chain diester compounds, and the fatty chain triester compounds in mixture S-3# account for 98wt%, 0.1wt%, and 1.9wt%, respectively. The number average molecular weight is 314, and the average functionality is 3.1.

[0065] (2) Preparation of fatty chain polyols: Propylene oxide was introduced into the reactor at a molar ratio of 0.6:1 with the mixture S-3#, and a ring-opening polymerization reaction was carried out at 120°C and a gauge pressure of 0.6 MPa. After the reaction was completed, the crude fatty chain polyol was aged and the small molecular compounds were removed to obtain the fatty chain polyol. After refining treatment, the fatty chain polyol B-3# was obtained. After testing, the fatty chain monoester compound of B-3# accounted for 98wt%, the fatty chain diester compound accounted for 0.1wt%, the fatty chain triester compound accounted for 1.9wt%, the average hydroxyl value was 503mgKOH / g, and the average functionality was 3.1.

[0066] Example 4

[0067] (1) Preparation of mixture S: epoxidized rapeseed oil, a second hydroxy compound (water, methanol and butanol), a solid acid catalyst Cat1# and triethylbenzyl ammonium chloride are added to a reactor, wherein the molar amount of water is 0.8 times the molar amount of epoxy groups, the molar amount of methanol is 2.0 times the molar amount of epoxy groups, the molar amount of butanol is 2.0 times the molar amount of epoxy groups, the amount of Cat1# used is 10% of the mass of the epoxidized vegetable oil, and the amount of triethylbenzyl ammonium chloride used is 0.05% of the mass of the epoxidized vegetable oil. The mixture is heated at 100°C. Ring and ester exchange reaction, after the reaction is completed, cooling and filtering, removing the unreacted second hydroxyl compound and small molecular substances from the filtrate under vacuum conditions, to obtain a mixture D-4# containing a low-functionality monoester compound. After testing, the ring opening rate of the ring opening reaction is 99.2%, the epoxy value of the mixture D-4# is 0.042 mol / 100g, the average functionality is 1.5, the fatty chain monoester compound accounts for 99wt%, the fatty chain diester compound accounts for 0wt%, and the fatty chain triester compound accounts for 1.0wt%;

[0068] Add mixture D-4#, the first hydroxy compound (pentaerythritol) and alkaline catalyst sodium carbonate into a reactor, wherein the molar ratio of the first hydroxy compound to mixture D-4# is 10:1, and the amount of sodium carbonate used is 3.0% of the total mass of mixture D-4#. Perform ester exchange reaction at 40°C, and obtain mixture S-4# containing fatty chain monoester compounds after completion of the reaction. According to testing, the fatty chain monoester compounds, the fatty chain diester compounds, and the fatty chain triester compounds in mixture S-4# account for 99wt%, 0wt%, and 1.0wt%, respectively. The number average molecular weight is 357, and the average functionality is 3.8.

[0069] (2) Preparation of fatty chain polyols: Propylene oxide and ethylene oxide were introduced into a reactor at a molar ratio of 2.6:1 to the mixture S-4#, and a ring-opening polymerization reaction was carried out at 70°C and a gauge pressure of 1.0 MPa. After the reaction was completed, the crude fatty chain polyol was aged and the small molecular compounds were removed to obtain a fatty chain polyol. After refining treatment, a fatty chain polyol B-4# was obtained. After testing, the fatty chain monoester compound of B-4# accounted for 99wt%, the fatty chain diester compound accounted for 0wt%, the fatty chain triester compound accounted for 1.0wt%, the average hydroxyl value was 407mgKOH / g, and the average functionality was 3.6.

[0070] Example 5

[0071] (1) Preparation of mixture S: epoxidized cottonseed oil, a second hydroxy compound (water and butanol), a solid acid catalyst Cat2# and tetrabutylammonium bromide are added to a reactor, wherein the molar amount of water is 1.1 times the molar amount of the epoxy group, the molar amount of butanol is 5.0 times the molar amount of the epoxy group, the amount of Cat2# used is 15% of the mass of the epoxidized vegetable oil, and the amount of tetrabutylammonium bromide used is 0.5% of the mass of the epoxidized vegetable oil. Ring-opening and transesterification reactions are carried out at 90° C. After the reaction is completed, the mixture is cooled and filtered, and the unreacted second hydroxy compound and small molecular substances are removed from the filtrate under vacuum conditions to obtain a mixture D-5# containing a low-functionality monoester compound. After testing, the ring-opening rate of the ring-opening reaction is 99.3%, the epoxy value of the mixture D-5# is 0.043 mol / 100 g, the average functionality is 1.2, the proportion of fatty chain monoester compounds is 98wt%, the proportion of fatty chain diester compounds is 0.1wt%, and the proportion of fatty chain triester compounds is 1.9wt%;

[0072] Mixture D-5#, the first hydroxy compound (sorbitol) and alkaline catalyst calcium oxide are added into a reactor, wherein the molar ratio of the first hydroxy compound to mixture D-5# is 5:1, and the amount of calcium oxide used is 5.0% of the total mass of mixture D-5#. An ester exchange reaction is carried out at 70°C. After the reaction, a mixture S-5# containing fatty chain monoester compounds is obtained. After testing, the fatty chain monoester compounds of mixture S-5# account for 98wt%, the fatty chain diester compounds account for 0.1wt%, the fatty chain triester compounds account for 1.9wt%, the number average molecular weight is 334, and the average functionality is 5.3.

[0073] (2) Preparation of fatty chain polyols: Propylene oxide and ethylene oxide were introduced into a reactor at a molar ratio of 3.4:1 to the mixture S-5#, and a ring-opening polymerization reaction was carried out at 160°C and a gauge pressure of 0 MPa. After the reaction was completed, the crude fatty chain polyol was aged and the small molecular compounds were removed to obtain a fatty chain polyol. After refining treatment, a fatty chain polyol B-5# was obtained. After testing, the fatty chain monoester compound of B-5# accounted for 98wt%, the fatty chain diester compound accounted for 0.1wt%, the fatty chain triester compound accounted for 1.9wt%, the average hydroxyl value was 550mgKOH / g, and the average functionality was 5.2.

[0074] The implementation method of the second approach of the present invention is Example 6 to Example 10

[0075] Example 6

[0076] (1) Preparation of mixture S: Add epoxidized soybean oil, a third hydroxyl compound (water and ethylene glycol) and a solid acid catalyst Cat1# to a reactor, wherein the molar amount of water is 1.5 times the molar amount of the epoxy group, the molar amount of ethylene glycol is 2.0 times the molar amount of the epoxy group, and the amount of Cat1# used is 10% of the mass of the epoxidized vegetable oil. A ring-opening reaction is carried out at 50°C. After the reaction is completed, the mixture is cooled and filtered, and the unreacted third hydroxyl compound and small molecular substances are removed from the filtrate under vacuum conditions to obtain a hydroxylated polyester compound E-1#. After testing, the ring-opening rate of the ring-opening reaction is 99.6%, the epoxy value of compound E-1# is 0.027 mol / 100 g, the average functionality is 6.2, the proportion of fatty chain monoester compounds is 0.5wt%, the proportion of fatty chain diester compounds is 1.4wt%, and the proportion of fatty chain triester compounds is 98.1wt%;

[0077] Add mixture E-1#, the first hydroxy compound (glycerol) and alkaline catalyst sodium hydroxide into a reactor, wherein the molar ratio of the first hydroxy compound to mixture E-1# is 20:1, and the amount of sodium hydroxide used is 3.0% of the total mass of mixture E-1#. Perform ester exchange reaction at 130°C, and obtain mixture S-6# containing fatty chain monoester compounds after completion of the reaction. After testing, the fatty chain monoester compounds, the fatty chain diester compounds, the fatty chain triester compounds, the number average molecular weight, the average functionality, the number average molecular weight, the average molecular weight, the average functionality, the average functionality, the average functionality, the average molecular weight ... molecular weight, the average functionality, the average molecular weight, the average functionality, the average molecular weight, the average functionality, the average molecular weight, the average functionality, the average molecular weight, the average functionality, the average molecular weight, the average molecular weight, the average functionality, the average molecular weight, the average functionality, the average molecular weight, the average functionality, the

[0078] (2) Preparation of fatty chain polyols: Propylene oxide was introduced into the reactor at a molar ratio of 0.5:1 to the mixture S-6#, and a ring-opening polymerization reaction was carried out at 90°C and a gauge pressure of 1.0 MPa. After the reaction was completed, the crude fatty chain polyol was aged and the small molecular compounds were removed to obtain the fatty chain polyol. After refining treatment, the fatty chain polyol B-6# was obtained. After testing, the fatty chain monoester compound of B-6# accounted for 88.1wt%, the fatty chain diester compound accounted for 0.2wt%, the fatty chain triester compound accounted for 11.7wt%, the average hydroxyl value was 501mgKOH / g, and the average functionality was 4.7.

[0079] Example 7

[0080] (1) Preparation of mixture S: epoxy linseed oil, a third hydroxy compound (propylene glycol) and a solid acid catalyst Cat2# are added to a reactor, wherein the molar amount of propylene glycol is 4.0 times the molar amount of the epoxy group, and the amount of Cat2# used is 15% of the mass of the epoxy vegetable oil. A ring-opening reaction is carried out at 40°C. After the reaction is completed, the mixture is cooled and filtered, and the unreacted third hydroxy compound and small molecular substances are removed from the filtrate under vacuum conditions to obtain a hydroxylated polyester compound E-2#. After testing, the ring-opening rate of the ring-opening reaction is 99.8%, the epoxy value of compound E-2# is 0.016 mol / 100 g, the average functionality is 7.3, the proportion of fatty chain monoester compounds is 3.8wt%, the proportion of fatty chain diester compounds is 5.1wt%, and the proportion of fatty chain triester compounds is 91.1wt%;

[0081] A mixture E-2#, a first hydroxy compound (trimethylolpropane) and an alkaline catalyst potassium methoxide are added into a reactor, wherein the molar ratio of the first hydroxy compound to the mixture E-2# is 8:1, and the amount of sodium hydroxide used is 2.0% of the total mass of the mixture E-2#. An ester exchange reaction is carried out at 150°C. After the reaction, a mixture S-7# containing fatty chain monoester compounds is obtained. After testing, the fatty chain monoester compounds of the mixture S-7# account for 92.3wt%, the fatty chain diester compounds account for 0.4wt%, the fatty chain triester compounds account for 7.3wt%, the number average molecular weight is 474, and the average functionality is 5.8.

[0082] (2) Preparation of fatty chain polyols: Propylene oxide was introduced into the reactor at a molar ratio of 4.3:1 to the mixture S-7#, and a ring-opening polymerization reaction was carried out at 110°C and a gauge pressure of 1.0 MPa. After the reaction was completed, the crude fatty chain polyol was aged and small molecular compounds were removed to obtain a fatty chain polyol. After refining treatment, a fatty chain polyol B-7# was obtained. After testing, the fatty chain monoester compound of B-7# accounted for 92.3wt%, the fatty chain diester compound accounted for 0.4wt%, the fatty chain triester compound accounted for 7.3wt%, the average hydroxyl value was 456mgKOH / g, and the average functionality was 5.8.

[0083] Example 8

[0084] (1) Preparation of mixture S: epoxy corn oil, a third hydroxy compound (diethylene glycol) and a solid acid catalyst Cat2# are added to a reactor, wherein the molar amount of diethylene glycol is 3.0 times the molar amount of the epoxy group, and the amount of Cat2# used is 3% of the mass of the epoxy vegetable oil. A ring-opening reaction is carried out at 80°C. After the reaction is completed, the mixture is cooled and filtered, and the unreacted third hydroxy compound and small molecular substances are removed from the filtrate under vacuum conditions to obtain a hydroxylated polyester compound E-3#. After testing, the ring-opening rate of the ring-opening reaction is 99.5%, the epoxy value of compound E-3# is 0.03 mol / 100 g, the average functionality is 6.8, the proportion of fatty chain monoester compounds is 0.7wt%, the proportion of fatty chain diester compounds is 2.9wt%, and the proportion of fatty chain triester compounds is 96.4wt%;

[0085] Add mixture E-3#, the first hydroxy compound (triglycerol) and alkaline catalyst calcium hydroxide into a reactor, wherein the molar ratio of the first hydroxy compound to mixture E-3# is 10:1, and the amount of calcium hydroxide used is 0.5% of the total mass of mixture E-3#. Perform ester exchange reaction at 200°C, and obtain mixture S-8# containing fatty chain monoester compounds after completion of the reaction. After testing, the fatty chain monoester compounds, the fatty chain diester compounds, and the fatty chain triester compounds in mixture S-8# account for 96.0wt%, 0.2wt%, and 3.8wt%, respectively. The number average molecular weight is 406, and the average functionality is 4.1.

[0086] (2) Preparation of fatty chain polyols: Propylene oxide and ethylene oxide were introduced into a reactor at a molar ratio of 4.5:1 to the mixture S-8#, and a ring-opening polymerization reaction was carried out at 120°C and a gauge pressure of 0.7 MPa. After the reaction was completed, the crude fatty chain polyol was aged and the small molecular compounds were removed to obtain a fatty chain polyol. After refining treatment, a fatty chain polyol B-8# was obtained. After testing, the fatty chain monoester compound of B-8# accounted for 96.0wt%, the fatty chain diester compound accounted for 0.2wt%, the fatty chain triester compound accounted for 3.8wt%, the average hydroxyl value was 354mgKOH / g, and the average functionality was 4.1.

[0087] Example 9

[0088] (1) Preparation of mixture S: epoxy rapeseed oil, a third hydroxy compound (dipropylene glycol) and a solid acid catalyst Cat4# are added to a reactor, wherein the molar amount of dipropylene glycol is 2.0 times the molar amount of the epoxy group, and the amount of Cat4# used is 6% of the mass of the epoxy vegetable oil. A ring-opening reaction is carried out at 70°C. After the reaction is completed, the mixture is cooled and filtered, and the unreacted third hydroxy compound and small molecular substances are removed from the filtrate under vacuum conditions to obtain a hydroxylated polyester compound E-4#. After testing, the ring-opening rate of the ring-opening reaction is 99.2%, the epoxy value of compound E-4# is 0.042 mol / 100 g, the average functionality is 5.1, the proportion of fatty chain monoester compounds is 0.5wt%, the proportion of fatty chain diester compounds is 3.8wt%, and the proportion of fatty chain triester compounds is 95.7wt%;

[0089] Add mixture E-4#, the first hydroxy compound (glycerol and sorbitol in a mass ratio of 1:1) and alkaline catalyst potassium hydroxide into a reactor, wherein the molar ratio of the first hydroxy compound to mixture E-4# is 5:1, and the amount of potassium hydroxide used is 1.0% of the total mass of mixture E-4#. Perform ester exchange reaction at 250°C, and obtain mixture S-9# containing fatty chain monoester compounds after completion of the reaction. According to testing, fatty chain monoester compounds account for 97.0wt% of mixture S-9#, fatty chain diester compounds account for 0.1wt%, fatty chain triester compounds account for 2.9wt%, the number average molecular weight is 378, and the average functionality is 4.8.

[0090] (2) Preparation of fatty chain polyols: Propylene oxide was introduced into the reactor at a molar ratio of 2.0:1 to the mixture S-9#, and a ring-opening polymerization reaction was carried out at 130° C. and a gauge pressure of 0.6 MPa. After the reaction was completed, the crude fatty chain polyol was aged and the small molecular compounds were removed to obtain a fatty chain polyol. After refining treatment, a fatty chain polyol B-9# was obtained. After testing, the fatty chain monoester compound of B-9# accounted for 97.0wt%, the fatty chain diester compound accounted for 0.1wt%, the fatty chain triester compound accounted for 2.9wt%, the average hydroxyl value was 549mgKOH / g, and the average functionality was 4.8.

[0091] Example 10

[0092] (1) Preparation of mixture S: epoxidized cottonseed oil, a third hydroxy compound (ethylene glycol) and a solid acid catalyst Cat1# are added to a reactor, wherein the molar amount of ethylene glycol is 1.0 times the molar amount of the epoxy group, and the amount of Cat1# used is 8% of the mass of the epoxidized vegetable oil. A ring-opening reaction is carried out at 60° C. After the reaction is completed, the mixture is cooled and filtered, and the unreacted third hydroxy compound and small molecular substances are removed from the filtrate under vacuum conditions to obtain a hydroxylated polyester compound E-5#. After testing, the ring-opening rate of the ring-opening reaction is 99.1%, the epoxy value of compound E-5# is 0.056 mol / 100 g, the average functionality is 2.0, the proportion of fatty chain monoester compounds is 1.1wt%, the proportion of fatty chain diester compounds is 5.0wt%, and the proportion of fatty chain triester compounds is 93.9wt%;

[0093] A mixture E-5#, a first hydroxy compound (glycerol and pentaerythritol in a mass ratio of 1:1) and an alkaline catalyst sodium methoxide are added into a reactor, wherein the molar ratio of the first hydroxy compound to the mixture E-5# is 10:1, and the amount of calcium hydroxide used is 5% of the total mass of the mixture E-5#. An ester exchange reaction is carried out at 230°C, and after the reaction, a mixture S-10# containing fatty chain monoester compounds is obtained. After testing, the fatty chain monoester compounds, the fatty chain diester compounds, the fatty chain triester compounds, the number average molecular weight, the average functionality, the number average molecular weight, and the average functionality are 3.7.

[0094] (2) Preparation of fatty chain polyols: Propylene oxide was introduced into the reactor at a molar ratio of 2.8:1 to the mixture S-10#, and a ring-opening polymerization reaction was carried out at 140°C and a gauge pressure of 0.5 MPa. After the reaction was completed, the crude fatty chain polyol was aged and the small molecular compounds were removed to obtain the fatty chain polyol. After refining treatment, the fatty chain polyol B-10# was obtained. After testing, the fatty chain monoester compound of B-10# accounted for 97.0wt%, the fatty chain diester compound accounted for 0.2wt%, the fatty chain triester compound accounted for 2.8wt%, the average hydroxyl value was 404mgKOH / g, and the average functionality was 3.6.

[0095] Comparative Example 1

[0096] Only the ring-opening reaction step in Example 9 was used to obtain a high-functionality hydroxylated polyester compound E-4#, and then E-4# was directly subjected to a ring-opening polymerization reaction with an olefin oxide, that is, propylene oxide was introduced into the reactor at a molar ratio of 2.0:1 to E-4#, and a ring-opening polymerization reaction was carried out at 130°C and a gauge pressure of 0.6 MPa. After the reaction was completed, the small molecule compounds were matured and removed to obtain a crude fatty chain polyol product, and a fatty chain polyol B-D1# was obtained after refining treatment. After testing, the fatty chain monoester compound of B-D1# accounted for 0.5wt%, the fatty chain diester compound accounted for 3.8wt%, the fatty chain triester compound accounted for 95.7wt%, the average hydroxyl value was 264mgKOH / g, and the average functionality was 4.9.

[0097] Comparative Example 2

[0098] The difference from Example 6 is that the ring-opening polymerization reaction of the mixture S and propylene oxide is not carried out, and only the mixture S-6# containing the fatty chain monoester compound is used as a comparison polyol, recorded as B-D2#, that is, the fatty chain monoester compound of B-D2# accounts for 88.1wt%, the fatty chain diester compound accounts for 0.2wt%, the fatty chain triester compound accounts for 11.7wt%, the average hydroxyl value is 524mgKOH / g, and the average functionality is 4.8.

[0099] Comparative Example 3

[0100] The difference from Example 8 is that an equal amount of sodium hydroxide is used to replace the solid acid catalyst Cat2#, and the other reaction conditions are the same as those in Example 8.

[0101] (1) Preparation of mixture S: Add epoxidized corn oil, a third hydroxyl compound (diethylene glycol) and sodium hydroxide into a reactor, wherein the molar amount of diethylene glycol is 3.0 times the molar amount of the epoxy group, and the amount of sodium hydroxide is 3% of the mass of the epoxidized vegetable oil, and carry out a ring-opening reaction at 80°C. After the reaction is completed, cool and filter, and remove the unreacted third hydroxyl compound and small molecular substances from the filtrate under vacuum conditions to obtain a hydroxylated polyester compound E-D1#. After testing, the ring-opening rate of the ring-opening reaction is 75.1%, the epoxy value of compound E-D1# is 1.5 mol / 100 g, the average functionality is 5.2, the proportion of fatty chain monoester compounds is 0.7wt%, the proportion of fatty chain diester compounds is 2.9wt%, and the proportion of fatty chain triester compounds is 96.4wt%;

[0102] Add mixture E-D1#, the first hydroxy compound (triglycerol) and alkaline catalyst calcium hydroxide into a reactor, wherein the molar ratio of the first hydroxy compound to mixture E-D1# is 10:1, and the amount of calcium hydroxide used is 0.5% of the total mass of mixture E-D1#. Perform ester exchange reaction at 200°C, and obtain mixture S-D3# containing fatty chain monoester compounds after completion of the reaction. After testing, the fatty chain monoester compounds, the fatty chain diester compounds, and the fatty chain triester compounds in mixture S-D3# account for 80.0wt%, 0.7wt%, and 19.3wt%, respectively. The number average molecular weight is 612, and the average functionality is 3.3.

[0103] (2) Preparation of fatty chain-based polyols: Propylene oxide was introduced into the reactor at a molar ratio of 2:1 to the mixture S-D3#, and a ring-opening polymerization reaction was carried out at 120°C and a gauge pressure of 0.7 MPa. After the reaction was completed, the crude fatty chain-based polyol was matured and the small molecular compounds were removed to obtain the fatty chain-based polyol. After refining treatment, the fatty chain-based polyol B-D3# was obtained. After testing, the fatty chain monoester compound of B-D3# accounted for 80.0wt%, the fatty chain diester compound accounted for 0.7wt%, the fatty chain triester compound accounted for 19.3wt%, the average hydroxyl value was 255mgKOH / g, and the average functionality was 3.3.

[0104] The fat chain-based polyol prepared as described above is used to prepare rigid polyurethane foam to examine its application effect and the compatibility between the fat chain-based polyol and the alkane foaming agent and the petroleum-based polyether. If the core density of the obtained rigid polyurethane foam is low under the same foaming agent dosage conditions, it means that the fat chain-based polyol has good compatibility with the foaming agent. If the fat chain-based polyol can cooperate with the petroleum-based polyether polyol in any proportion to obtain a rigid polyurethane foam with excellent comprehensive performance, it means that the fat chain-based polyol has good compatibility with the petroleum-based polyether polyol.

[0105] The sucrose polyether polyol used in the preparation of rigid polyurethane foam in the embodiment of the present invention is VORANOL TM 490, purchased from Dow; glycerol polyether polyol is H307, purchased from Hongbaoli; aromatic amine polyether polyol is Purchased from BASF; phthalic anhydride polyester polyol is purchased from Stepan; catalyst C is pentamethyldiethylenetriamine, N,N-dimethylcyclohexylamine and 1,3,5-tris(dimethylaminopropyl)-hexahydrotriazine in a mass ratio of 1:4.3:1.5; the foam stabilizer used is M-8825 purchased from Meside; the organic isocyanate is Purchased from BASF.

[0106] The rigid polyurethane foam of the present invention is prepared by mixing the materials with high-speed stirring, injecting the materials into a mold for curing and molding, wherein the material temperature is 0-30° C., the mold temperature is 38-42° C., and the mold cavity size is 2000mm×200mm×50mm.

[0107] Apparent core density, high temperature dimensional stability, thermal conductivity and compressive strength are all carried out in accordance with the method in GB / T 26689-2024 Rigid polyurethane foam plastics for refrigerators and freezers. Density distribution uniformity: It is expressed by the core density range, which is the difference between the maximum core density and the minimum core density measured at different sampling points on the same sample.

[0108] The rigid polyurethane foam was prepared according to the material formula in Table 1 below, and the performance of the prepared rigid polyurethane foam was characterized. The results are shown in Table 2.

[0109] Table 1 Rigid polyurethane foam formula composition

[0110]

[0111]

[0112] Table 2 Characterization results of rigid polyurethane foam properties

[0113]

[0114] From the data in the table, it can be seen that the rigid polyurethane foam prepared by using the fatty chain polyol of the present invention has a higher specific strength, that is, the ratio of compressive strength to core density is higher, and when the proportion of the fatty chain polyol is in the range of 5-100wt%, good comprehensive foam performance can be obtained, indicating that the fatty chain polyol of the present invention has good compatibility with petroleum-based polyether. However, the fatty chain polyol obtained in Comparative Example 1 has a high content of triester, resulting in low specific strength, increased system viscosity, and poor uniformity of density distribution; although the fatty chain polyol obtained in Comparative Example 2 has a good proportion of monoester, it does not further undergo a ring-opening polymerization reaction with oxidized olefins, resulting in poor compatibility with petroleum-based polyethers, poor performance such as uniformity of density distribution; Comparative Example 3 uses an alkaline catalyst for a ring-opening reaction, and the molecular weight of the resulting mixture S is relatively large, resulting in a low hydroxyl value of the fatty chain polyol, and thus low comprehensive foam performance.

Claims

1. A method for preparing a fatty chain polyol, characterized in that: The process uses epoxidized vegetable oil as raw material and comprises the following steps in sequence: Step 1), converting the epoxidized vegetable oil into a high-functionality mixture S containing fatty chain monoester compounds through a ring-opening reaction and an ester exchange reaction, wherein the number average molecular weight of the mixture S is less than 550 and the average functionality is greater than or equal to 3; Step 2) The high-functionality mixture S containing fatty chain monoester compounds is subjected to a ring-opening polymerization reaction with an oxidized olefin to obtain a fatty chain-based polyol.

2. The preparation method according to claim 1, characterized in that: The epoxidized vegetable oil is at least one of epoxidized soybean oil, epoxidized rapeseed oil, epoxidized castor oil, epoxidized tung oil, epoxidized cottonseed oil, epoxidized olive oil, epoxidized peanut oil, epoxidized coconut oil, epoxidized palm oil, epoxidized sesame oil, epoxidized sunflower seed oil, epoxidized linseed oil, epoxidized tung oil, epoxidized rice bran oil, and epoxidized corn oil.

3. The preparation method according to claim 1, wherein the ring-opening reaction is carried out under the action of a solid acid catalyst at a reaction temperature of 40 to 130°C, the transesterification reaction is carried out under the action of a solid acid catalyst and / or an alkaline catalyst at a reaction temperature of 40 to 250°C, and the ring-opening polymerization reaction temperature is 70 to 160°C.

4. The preparation method according to claim 3, characterized in that: The solid acid catalyst is a heteropolyacid salt, the structural formula of which is [(C n H 2n+1 )N(CH3)3]3PW4O 16 , where n=10~18.

5. The preparation method according to any one of claims 1 to 4, characterized in that: The step 1) sequentially comprises a first step of generating a low-functionality monoester compound and a second step of generating the high-functionality mixture S, wherein the average functionality of the low-functionality monoester compound is less than 3, the first step is a ring-opening reaction and an ester exchange reaction between the epoxidized vegetable oil and the second hydroxy compound in the presence of a solid acid catalyst and a quaternary ammonium salt phase transfer catalyst, and after the reaction is completed, a mixture D containing the low-functionality monoester compound is obtained, the second hydroxy compound is a mixture of water and a monohydric alcohol, and the second step is an ester exchange reaction between the mixture D and the first hydroxy compound in the presence of an alkaline catalyst to obtain the high-functionality mixture S.

6. The preparation method according to claim 5, characterized in that: The monohydric alcohol is at least one of methanol, ethanol, propanol and butanol.

7. The preparation method according to claim 5, characterized in that: The functionality of the first hydroxy compound is ≥3 and the molecular weight is <350.

8. The preparation method according to claim 7, characterized in that: The first hydroxy compound is at least one of glycerol, trimethylolpropane, polyglycerol, pentaerythritol, sorbitol and sucrose.

9. The preparation method according to claims 1 to 4, characterized in that: The step 1) comprises a first process in which the epoxidized vegetable oil undergoes a ring-opening reaction with a third hydroxyl compound under the action of a solid acid catalyst to generate a hydroxyl group, and a process in which the fatty acid ester group undergoes an ester exchange with the first hydroxyl compound under the action of an alkaline catalyst to form the high-functionality mixture S, wherein the functionality of the third hydroxyl compound is ≤3 and the molecular weight is <150.

10. The preparation method according to claim 9, characterized in that: The third hydroxy compound is at least one of water, ethylene glycol, propylene glycol, diethylene glycol, and dipropylene glycol.

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