A vegetable oil polyol and its preparation method and application

Abstract

The present invention belongs to the field of chemical materials and their production technology, and specifically relates to a vegetable oil polyol, its preparation method, and application. Epoxidized vegetable oil and an acidic catalyst are mixed to obtain a first mixed liquid; diglyceride of fatty acids is dissolved in an organic solvent to obtain a second mixed liquid; the first mixed liquid and the second mixed liquid are simultaneously pumped into a first microreactor of a microchannel reaction device for a first ring-opening reaction to obtain a first reaction liquid; hydroxycarboxylic acid ester is dissolved in an organic solvent to obtain a third mixed liquid; the first reaction liquid and the third mixed liquid are simultaneously pumped into a second microreactor of a microchannel reaction device for a second ring-opening reaction to obtain a second reaction liquid. After the reaction is completed, the reaction liquid is post-treated to obtain the obtained product. The present invention introduces polyester groups into the vegetable oil polyol prepared by using a new ring-opening reagent, thereby increasing the tensile properties of the polyurethane material.

Description

Technical Field

[0001] The present invention belongs to the technical field of chemical materials and production thereof, and particularly relates to a vegetable oil polyol and a preparation method and application thereof. Background Art

[0002] Polyurethane is a polymer with repeating urethane segments, produced by the reaction of isocyanates and polyols. Polyurethane products are categorized into two main categories: foamed and non-foamed. Foamed products include soft, rigid, and semi-rigid polyurethane foams; non-foamed products include coatings, adhesives, synthetic leather, flexible foams, and elastic fibers.

[0003] Traditional flexible foam polyether polyols use polyols such as glycerol, diethylene glycol, and propylene glycol as initiators, and propylene oxide and ethylene oxide as chain extenders. Over 98% of these polyols are petroleum derivatives. Currently, there is a desire to reduce dependence on petroleum and improve the environment. Compared to petroleum-based polyols, biomass-based polyols offer 23% lower energy consumption, 61% lower non-renewable resource consumption, and 36% lower greenhouse gas emissions. Replacing petroleum-based polyols with biomass-based polyols in polyurethane production has become a key development direction for polyurethane materials. Soybean oil, the cheapest and most abundant vegetable oil, can be molecularly modified to produce soybean-based polyols for use in polyurethane synthesis. The resulting polyurethane products are not only safe and hygienic, but also exhibit improved mechanical properties, thermal stability, and chemical resistance. The development of vegetable oil-based polyols is considered an effective path forward in the development of bio-based materials. As key monomers in bio-based polyurethane materials, vegetable oil-based polyols are derived from chemically modified plant oils, a significant renewable resource. They react with isocyanates to form polyurethanes, offering potential applications in numerous fields and serving as a promising alternative to petroleum-based polyols.

[0004] Researchers have conducted extensive research in this area. The main methods for synthesizing vegetable oil polyols include: 1) using the basic nucleus of triglycerides to hydrolyze vegetable oils with polyols to produce polyols. This approach can produce high-functionality polyol monomers, but the hydroxyl distribution is uneven and uncontrollable, limiting their application. 2) using ozone to oxidize unsaturated double bonds in vegetable oils to produce polyols with terminal hydroxyl groups. This approach can produce highly reactive terminal hydroxyl groups, but poor atom economy and low functionality significantly limit their downstream applications. 3) oxidizing vegetable oils to epoxidized vegetable oils and then generating polyols through ring-opening reactions. This approach offers high atom economy and the advantages of flexibility, structural controllability, and molecular diversity, making it the main method for developing bio-based polyols. However, the selection of ring-opening reagents, the control of process parameters, and the arrangement and ratio of multiple ring-opening reagents all affect the quality of the polyols and their downstream applications. Therefore, developing bio-based polyols with market potential that do not require compatibility with petrochemical polyols is a challenging task.

[0005] The long-chain groups in the vegetable oil structure replace the repeating units of traditional petrochemical polyol polyethers or polyesters. The triglyceride core in the structure has a star-shaped spatial conformation, which endows downstream polyurethanes with more functional properties and application potential. However, vegetable oil polyols often suffer from performance drawbacks, primarily due to the uncontrollable reaction process. During the functional group conversion process, multiple epoxy and ester groups often participate in multiple side reactions. This makes the designed molecular structure difficult to construct using traditional chemical methods, significantly limiting the quality of the polyol. Mixing with traditional petrochemical polyols is often necessary to achieve a certain application effect. Analysis of the reaction mechanism suggests that the main reason is that oil esters often have poor miscibility with the reaction reagents and low reactivity, resulting in long and intensive reactions. However, the influence of multiple functional groups in the structure makes it difficult to balance reaction selectivity and conversion rate, resulting in poor process control, resulting in poor molecular uniformity, high viscosity, and significant differences in macroscopic and microscopic indicators between individual molecules. Therefore, even though vegetable oil prices are often lower than those of the monomers containing petrochemical repeating units, it is difficult to obtain vegetable oil polyol products that have both cost and quality advantages. It is necessary to control product quality through chemical process control. In this reaction system, the use of micro-reaction technology to intensify the chemical reaction process and continuously and precisely control it is an effective solution.

[0006] Generally speaking, polyurethane products formed from polyester polyols are superior to those formed from polyether polyols in terms of mechanical strength. This may be due to the potential effect of hydrogen bonds formed between the ester groups in the polyols and the amino groups in the isocyanate. In addition, in order to enhance the rigidity of polyester / polyether polyols, rigid groups can be introduced into the ring-opening reagent. Previous experiments have found that the introduction of phenyl and pyridine groups may increase the hardness of the product but reduce its toughness. The introduction of cycloalkanes can increase the strength while maintaining its toughness. Therefore, the coordination of various aspects such as increasing a certain proportion of ester groups and rigid groups in the molecular structure, adjusting the distribution of pendant chains, and controlling the ring-opening efficiency to maintain controllable viscosity are the main issues that need to be addressed. At present, given that the composition of vegetable oils is not single and the structure-activity relationship is unclear, the quality control of polyol products can only be carried out through reaction process control and macro-indicator regulation. Therefore, controlling product uniformity through process control as much as possible plays an important role in the development of new polyol products and downstream applications.

[0007] Currently, polyurethane soft foam products are often used in pillows, mattresses, etc. They need to have good mechanical properties and a comfortable feel. However, these two are often difficult to coordinate in current material development. Researchers are pursuing soft foam materials with a surface hardness close to 0 and good mechanical properties. Therefore, they have high requirements for the molecular structure and uniformity of the material. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a vegetable oil polyol and a preparation method and application thereof in view of the deficiencies in the prior art.

[0009] The inventive concept: To improve the tensile properties of downstream polyester polyol products, a ring-opening reagent containing both hydroxyl and ester groups is used as the first ring-opening reagent. Through process control, the ring-opening reaction of some readily reactive epoxy groups is completed. The remaining epoxy groups are then subjected to a ring-opening reaction with a highly reactive primary alcohol containing a long-chain ester group, resulting in a vegetable oil polyol product with a low residual epoxy value. To avoid crosslinking side reactions caused by non-selective ring-opening of secondary hydroxyl groups and other epoxy groups generated during the ring-opening reaction, the inventors employed microreaction technology, using a microchannel reactor as the reaction apparatus, to further control the ring-opening groups.

[0010] In order to solve the above technical problems, the technical solutions adopted by the present invention are as follows:

[0011] The present invention discloses a method for preparing vegetable oil polyols, comprising the following steps:

[0012] (1) mixing epoxidized vegetable oil and an acidic catalyst to obtain a first mixed solution; dissolving diglyceride in an organic solvent to obtain a second mixed solution; and simultaneously pumping the first mixed solution and the second mixed solution into a first microreactor of a microchannel reaction device to perform a first ring-opening reaction to obtain a first reaction solution;

[0013] (2) dissolving the hydroxycarboxylate in an organic solvent to obtain a third mixed solution; and simultaneously pumping the first reaction solution obtained in step (1) and the third mixed solution into a second microreactor of a microchannel reaction device to perform a second ring-opening reaction to obtain a second reaction solution. After the reaction is completed, the reaction solution is post-treated to obtain a vegetable oil polyol.

[0014] In some embodiments, the epoxidized vegetable oil is any one or a combination of epoxidized olive oil, epoxidized peanut oil, epoxidized rapeseed oil, epoxidized cottonseed oil, epoxidized soybean oil, epoxidized coconut oil, epoxidized palm oil, epoxidized sesame oil, epoxidized corn oil and epoxidized sunflower oil, preferably epoxidized soybean oil, epoxidized cottonseed oil, epoxidized sunflower oil, epoxidized rapeseed oil, epoxidized corn oil or epoxidized peanut oil, more preferably epoxidized soybean oil.

[0015] In some embodiments, the acidic catalyst is any one or a combination of fluoroboric acid, concentrated sulfuric acid, p-toluenesulfonic acid, methanesulfonic acid and benzenesulfonic acid, preferably fluoroboric acid.

[0016] In some embodiments, the diglyceride is any one of dilaurin, diolein and distearin, or a combination thereof, preferably dilaurin.

[0017] In some embodiments, the organic solvent is any one or a combination of ethyl acetate, dichloromethane, dichloroethane, chloroform, n-hexane, tetrahydrofuran, 1,4-dioxane, carbon tetrachloride, toluene and xylene, preferably ethyl acetate.

[0018] In some embodiments, the hydroxycarboxylic acid ester is any one of 4-hydroxybutyric acid methyl ester, 4-hydroxybutyric acid ethyl ester, 6-hydroxyhexanoic acid methyl ester, 6-hydroxyhexanoic acid ethyl ester, 8-hydroxyoctanoic acid methyl ester, 8-hydroxyoctanoic acid ethyl ester, 10-hydroxydecanoic acid methyl ester and 10-hydroxydecanoic acid ethyl ester, or a combination thereof, preferably 4-hydroxybutyric acid ethyl ester, 6-hydroxyhexanoic acid methyl ester, 8-hydroxyoctanoic acid ethyl ester or 10-hydroxydecanoic acid methyl ester, more preferably 8-hydroxyoctanoic acid ethyl ester.

[0019] In some embodiments, in step (1), the mass ratio of the acidic catalyst to the epoxidized vegetable oil is 0.02-0.1%:1, preferably 0.06-0.1%:1; the molar ratio of the diglyceride to the epoxy group in the epoxidized vegetable oil is 0.4-0.6:1, preferably 0.5:1; the mass volume ratio of the epoxidized vegetable oil to the organic solvent is 1 g:0.5-2 mL, preferably 1 g:0.7-1.2 mL, and more preferably 1 g:1 mL.

[0020] In some embodiments, in step (1), the flow rate of the first mixed liquid pumped into the first microreactor of the microchannel reaction device is 0.5-2 mL / min, preferably 1 mL / min; the flow rate of the second mixed liquid pumped into the first microreactor of the microchannel reaction device is 0.7-3 mL / min, preferably 1.5 mL / min; the volume of the first microreactor is 10-20 mL, preferably 15 mL; the reaction temperature of the first ring-opening reaction is 80-100°C, preferably 90°C.

[0021] In some embodiments, the molar ratio of the hydroxycarboxylic acid ester in step (2) to the epoxy groups in the epoxidized vegetable oil in step (1) is 0.3 to 0.5:1, preferably 0.4:1.

[0022] In some embodiments, the mass volume ratio of the epoxidized vegetable oil in step (1) to the organic solvent in step (2) is 1 g:1-4 mL, preferably 1 g:1.4-2.5 mL, and more preferably 1 g:2 mL.

[0023] In some embodiments, in step (2), the flow rate of the first reaction liquid pumped into the second microreactor of the microchannel reaction device is: the sum of the flow rate of the first mixed liquid pumped into the first microreactor of the microchannel reaction device and the flow rate of the second mixed liquid pumped into the first microreactor of the microchannel reaction device in step (1); the flow rate of the third mixed liquid pumped into the second microreactor of the microchannel reaction device is 1 to 5 mL / min, preferably 2.5 mL / min.

[0024] In some embodiments, in step (2), the volume of the second microreactor is 15-25 mL, preferably 20 mL; and the reaction temperature of the second ring-opening reaction is 80-100°C, preferably 90°C.

[0025] Wherein, in step (2), the post-treatment of the reaction solution is: washing the reaction solution with sodium bicarbonate solution and water in sequence, drying and concentrating the organic phase to obtain vegetable oil polyol.

[0026] In some embodiments, the microchannel reaction device includes a first feed pump, a second feed pump, a third feed pump, a microreaction pipe, a first micromixer, a second micromixer, a first microreactor, a second microreactor and a receiver; the first feed pump and the second feed pump are connected to the first micromixer in parallel through a pipe; the first micromixer is connected to the first microreactor through a pipe; the first microreactor and the third feed pump are connected to the second micromixer in parallel through a pipe; the second micromixer, the second microreactor and the receiver are connected in series in sequence through pipes.

[0027] The first micromixer and the second micromixer are conventional Y-type mixers or T-type mixers, preferably Y-type mixers; the first microreactor and the second microreactor are Vapotech models, and use a coaxial heat exchanger.

[0028] The vegetable oil polyols prepared by the above-mentioned preparation method are also within the protection scope of the present invention.

[0029] The use of the above-mentioned vegetable oil polyols in the preparation of bio-based polyurethane flexible foams is also within the scope of protection of the present invention.

[0030] Beneficial effects:

[0031] (1) The present invention introduces polyester groups into the vegetable oil polyol prepared by using a new ring-opening reagent, thereby increasing the tensile properties of the polyurethane material.

[0032] (2) The present invention adopts a series reaction of two specific types of ring-opening reagents to prepare a novel vegetable oil polyol. The polyol is moderate and evenly distributed, has a low viscosity, and can replace traditional petrochemical polyols. The performance of polyurethane soft foam prepared by the vegetable oil polyol prepared by the present invention is significantly improved, and the surface hardness is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, and the above and / or other advantages of the present invention will become more apparent.

[0034] Figure 1 Schematic diagram of the microchannel reaction device of the present invention. DETAILED DESCRIPTION

[0035] The present invention can be better understood according to the following examples. However, it is easy for those skilled in the art to understand that the contents described in the examples are only used to illustrate the present invention, and should not and will not limit the present invention described in detail in the claims.

[0036] The relevant determination methods of the prepared vegetable oil polyol and polyurethane material of the present invention are as follows:

[0037] (1) Measure the hydroxyl value according to GB / T 12008.3-2009;

[0038] (2) Viscosity measurement according to GB / T 12008.7-2010;

[0039] (3) Measure epoxy value according to GB / T 1677-2008;

[0040] (4) Determine the tensile strength of flexible foam according to GB / T 24451-2009;

[0041] (5) Determine elongation according to GB6344-2008;

[0042] (6) Determine the surface hardness according to GB / T 10807-1989;

[0043] (7) Tear strength was measured according to GB10808-2006;

[0044] In an embodiment of the present invention, the flow rate at which the first reaction liquid is pumped into the second microreactor of the microchannel reaction device is: the sum of the flow rate at which the first mixed liquid is pumped into the first microreactor of the microchannel reaction device in step (1) and the flow rate at which the second mixed liquid is pumped into the first microreactor of the microchannel reaction device.

[0045] Figure 1 This is a schematic diagram of the microchannel reaction device of the present invention, which includes a first feed pump, a second feed pump, a third feed pump, a microreaction pipeline, a first micromixer, a second micromixer, a first microreactor, a second microreactor, and a receiver; the first feed pump and the second feed pump are connected to the first micromixer in parallel through pipelines; the first micromixer is connected to the first microreactor through a pipeline; the first microreactor and the third feed pump are connected to the second micromixer in parallel through pipelines; the second micromixer, the second microreactor, and the receiver are connected in series in sequence through pipelines.

[0046] The first micro-mixer and the second micro-mixer are Y-type mixers; the first micro-reactor and the second micro-reactor are Vapotech models, and use a coaxial heat exchanger with a microstructure.

[0047] The reaction temperatures in the first microreactor and the second microreactor are controlled by heating in an oil bath.

[0048] The fluoroboric acid used in the embodiment of the present invention is a 50 wt. % fluoroboric acid aqueous solution.

[0049] Example 1

[0050] (1) Preparation of vegetable oil polyols: Epoxidized soybean oil (10 g, epoxy value 6.2%, epoxy group 38.4 mmol) and fluoroboric acid (20 mg, 50 wt.%) were mixed to obtain a first mixed solution; dilaurin (8.77 g, 19.2 mmol) was dissolved in ethyl acetate (10 mL) to obtain a second mixed solution; the temperature of the first microreactor was adjusted to 90°C, and the first mixed solution and the second mixed solution were simultaneously pumped into the first microreactor (15 mL) of a microchannel reaction device at a rate of 1 mL / min and 1.5 mL / min, respectively, for a ring-opening reaction to obtain a first reaction solution.

[0051] (2) 8-Hydroxyoctanoic acid ethyl ester (2.89 g, 15.4 mmol) was dissolved in ethyl acetate (20 mL) to obtain a third mixed solution; the temperature of the second microreactor was adjusted to 90° C., and the third mixed solution and the first reaction solution obtained in step (1) were simultaneously pumped into the second microreactor (20 mL) of the microchannel reaction device at a rate of 2.5 mL / min for a ring-opening reaction to obtain a second reaction solution; after the reaction was completed, the reaction solution was washed with sodium bicarbonate solution (30 mL, 10 wt.%) and water (30 mL×2) in sequence, and the organic phase was dried and concentrated to obtain soybean oil polyol with a hydroxyl value of 80 mg KOH / g, an epoxy value of 0.3, and a viscosity of 502 mPa·s.

[0052] (3) Preparation of plant oil-based polyurethane soft foam: Under nitrogen protection, polyurethane soft foam was prepared by the prepolymer method. 100 g of bio-based polyurethane polyol (prepared in step (2)) was mixed with 1.5 g of water, 1.0 g of silicone oil, 2 g of pore opener, 0.3 g of catalyst A-33, 0.1 g of catalyst A-1, and 0.006 g of catalyst T-12. 100 g of 4,4'-diphenylmethane diisocyanate was added. After reacting at 80°C for 2 h, the free NCO content was determined by the di-n-butylamine method. 1,4-Butanediol was added according to the chain extension coefficient of 0.95. After stirring and mixing evenly, the mixture was poured into a flat steel mold at 100°C and vulcanized. The mixture was aged in an oven at 90°C for 24 h to obtain bio-based polyurethane soft foam.

[0053] Example 2

[0054] (1) Preparation of vegetable oil polyols: Epoxidized soybean oil (10 g, epoxy value 6.2%, epoxy group 38.4 mmol) and fluoroboric acid (20 mg, 50 wt.%) were mixed to obtain a first mixed solution; dilaurin (6.99 g, 15.3 mmol) was dissolved in ethyl acetate (10 mL) to obtain a second mixed solution; the temperature of the first microreactor was adjusted to 90°C, and the first mixed solution and the second mixed solution were simultaneously pumped into the first microreactor (15 mL) of a microchannel reaction device at a rate of 1 mL / min and 1.4 mL / min, respectively, for a ring-opening reaction to obtain a first reaction solution.

[0055] (2) 8-hydroxyoctanoic acid ethyl ester (3.61 g, 19.2 mmol) was dissolved in ethyl acetate (20 mL) to obtain a third mixed solution; the temperature of the second microreactor was adjusted to 90° C., and the third mixed solution and the first reaction solution obtained in step (1) were simultaneously pumped into the second microreactor (20 mL) of the microchannel reaction device at a rate of 2.4 mL / min for a ring-opening reaction to obtain a second reaction solution; after the reaction was completed, the reaction solution was washed with sodium bicarbonate solution (30 mL, 10 wt.%) and water (30 mL×2) in sequence, and the organic phase was dried and concentrated to obtain soybean oil polyol with a hydroxyl value of 85 mg KOH / g, an epoxy value of 0.3, and a viscosity of 621 mPa·s.

[0056] (3) Preparation of plant oil-based polyurethane soft foam: Bio-based polyurethane soft foam was prepared according to the preparation method of step (3) in Example 1.

[0057] Example 3

[0058] (1) Preparation of vegetable oil polyols: Epoxidized soybean oil (10 g, epoxy value 6.2%, epoxy group 38.4 mmol) and fluoroboric acid (20 mg, 50 wt.%) were mixed to obtain a first mixed solution; dilaurin (10.55 g, 23.1 mmol) was dissolved in ethyl acetate (10 mL) to obtain a second mixed solution; the temperature of the first microreactor was adjusted to 90°C, and the first mixed solution and the second mixed solution were simultaneously pumped into the first microreactor (15 mL) of a microchannel reaction device at a rate of 1 mL / min and 1.6 mL / min, respectively, for a ring-opening reaction to obtain a first reaction solution.

[0059] (2) 8-Hydroxyoctanoic acid ethyl ester (2.17 g, 11.5 mmol) was dissolved in ethyl acetate (20 mL) to obtain a third mixed solution; the temperature of the second microreactor was adjusted to 90° C., and the third mixed solution and the first reaction solution obtained in step (1) were simultaneously pumped into the second microreactor (20 mL) of the microchannel reaction device at a rate of 2.6 mL / min for a ring-opening reaction to obtain a second reaction solution; after the reaction was completed, the reaction solution was washed with sodium bicarbonate solution (30 mL, 10 wt.%) and water (30 mL×2) in sequence, and the organic phase was dried and concentrated to obtain soybean oil polyol with a hydroxyl value of 76 mg KOH / g, an epoxy value of 0.3, and a viscosity of 436 mPa·s.

[0060] (3) Preparation of plant oil-based polyurethane soft foam: Bio-based polyurethane soft foam was prepared according to the preparation method of step (3) in Example 1.

[0061] Example 4

[0062] (1) Preparation of vegetable oil polyols: Epoxidized soybean oil (10 g, epoxy value 6.2%, epoxy group 38.4 mmol) and fluoroboric acid (20 mg, 50 wt.%) were mixed to obtain a first mixed solution; dilaurin (6.99 g, 15.3 mmol) was dissolved in ethyl acetate (10 mL) to obtain a second mixed solution; the temperature of the first microreactor was adjusted to 90°C, and the first mixed solution and the second mixed solution were simultaneously pumped into the first microreactor (15 mL) of a microchannel reaction device at a rate of 1 mL / min and 1.4 mL / min, respectively, for a ring-opening reaction to obtain a first reaction solution.

[0063] (2) 8-Hydroxyoctanoic acid ethyl ester (2.17 g, 11.5 mmol) was dissolved in ethyl acetate (20 mL) to obtain a third mixed solution; the temperature of the second microreactor was adjusted to 90° C., and the third mixed solution and the first reaction solution obtained in step (1) were simultaneously pumped into the second microreactor (20 mL) of the microchannel reaction device at a rate of 2.4 mL / min for a ring-opening reaction to obtain a second reaction solution; after the reaction was completed, the reaction solution was washed with sodium bicarbonate solution (30 mL, 10 wt.%) and water (30 mL×2) in sequence, and the organic phase was dried and concentrated to obtain soybean oil polyol with a hydroxyl value of 69 mg KOH / g, an epoxy value of 0.9, and a viscosity of 374 mPa·s.

[0064] (3) Preparation of plant oil-based polyurethane soft foam: Bio-based polyurethane soft foam was prepared according to the preparation method of step (3) in Example 1.

[0065] Example 5

[0066] (1) Preparation of vegetable oil polyols: Epoxidized soybean oil (10 g, epoxy value 6.2%, epoxy group 38.4 mmol) and fluoroboric acid (20 mg, 50 wt.%) were mixed to obtain a first mixed solution; dilaurin (10.55 g, 23.1 mmol) was dissolved in ethyl acetate (10 mL) to obtain a second mixed solution; the temperature of the first microreactor was adjusted to 90°C, and the first mixed solution and the second mixed solution were simultaneously pumped into the first microreactor (15 mL) of a microchannel reaction device at a rate of 1 mL / min and 1.6 mL / min, respectively, for a ring-opening reaction to obtain a first reaction solution.

[0067] (2) 8-Hydroxyoctanoic acid ethyl ester (2.89 g, 15.4 mmol) was dissolved in ethyl acetate (20 mL) to obtain a third mixed solution; the temperature of the second microreactor was adjusted to 90° C., and the third mixed solution and the first reaction solution obtained in step (1) were simultaneously pumped into the second microreactor (20 mL) of the microchannel reaction device at a rate of 2.6 mL / min for a ring-opening reaction to obtain a second reaction solution; after the reaction was completed, the reaction solution was washed with sodium bicarbonate solution (30 mL, 10 wt.%) and water (30 mL×2) in sequence, and the organic phase was dried and concentrated to obtain soybean oil polyol with a hydroxyl value of 82 mg KOH / g, an epoxy value of 0.1, and a viscosity of 528 mPa·s.

[0068] (3) Preparation of plant oil-based polyurethane soft foam: Bio-based polyurethane soft foam was prepared according to the preparation method of step (3) in Example 1.

[0069] Example 6

[0070] (1) Preparation of vegetable oil polyols: Epoxidized soybean oil (10 g, epoxy value 6.2%, epoxy group 38.4 mmol) and fluoroboric acid (20 mg, 50 wt.%) were mixed to obtain a first mixed solution; dilaurin (8.77 g, 19.2 mmol) was dissolved in ethyl acetate (10 mL) to obtain a second mixed solution; the temperature of the first microreactor was adjusted to 80°C, and the first mixed solution and the second mixed solution were simultaneously pumped into the first microreactor (15 mL) of a microchannel reaction device at a rate of 1 mL / min and 1.5 mL / min, respectively, for a ring-opening reaction to obtain a first reaction solution.

[0071] (2) 8-Hydroxyoctanoic acid ethyl ester (2.89 g, 15.4 mmol) was dissolved in ethyl acetate (20 mL) to obtain a third mixed solution; the temperature of the second microreactor was adjusted to 80° C., and the third mixed solution and the first reaction solution obtained in step (1) were simultaneously pumped into the second microreactor (20 mL) of the microchannel reaction device at a rate of 2.5 mL / min for a ring-opening reaction to obtain a second reaction solution; after the reaction was completed, the reaction solution was washed with sodium bicarbonate solution (30 mL, 10 wt.%) and water (30 mL×2) in sequence, and the organic phase was dried and concentrated to obtain soybean oil polyol with a hydroxyl value of 70 mg KOH / g, an epoxy value of 0.3, and a viscosity of 392 mPa·s.

[0072] (3) Preparation of plant oil-based polyurethane soft foam: Bio-based polyurethane soft foam was prepared according to the preparation method of step (3) in Example 1.

[0073] Example 7

[0074] (1) Preparation of vegetable oil polyols: Epoxidized soybean oil (10 g, epoxy value 6.2%, epoxy group 38.4 mmol) and fluoroboric acid (20 mg, 50 wt.%) were mixed to obtain a first mixed solution; dilaurin (8.77 g, 19.2 mmol) was dissolved in ethyl acetate (10 mL) to obtain a second mixed solution; the temperature of the first microreactor was adjusted to 100°C, and the first mixed solution and the second mixed solution were simultaneously pumped into the first microreactor (15 mL) of a microchannel reaction device at a rate of 1 mL / min and 1.5 mL / min, respectively, for a ring-opening reaction to obtain a first reaction solution.

[0075] (2) 8-hydroxyoctanoic acid ethyl ester (2.89 g, 15.4 mmol) was dissolved in ethyl acetate (20 mL) to obtain a third mixed solution; the temperature of the second microreactor was adjusted to 100° C., and the third mixed solution and the first reaction solution obtained in step (1) were simultaneously pumped into the second microreactor (20 mL) of the microchannel reaction device at a rate of 2.5 mL / min for ring-opening reaction to obtain a second reaction solution; after the reaction was completed, the reaction solution was washed with sodium bicarbonate solution (30 mL, 10 wt.%) and water (30 mL×2) in sequence, and the organic phase was dried and concentrated to obtain soybean oil polyol with a hydroxyl value of 75 mg KOH / g, an epoxy value of 0.3, and a viscosity of 413 mPa·s.

[0076] (3) Preparation of plant oil-based polyurethane soft foam: Bio-based polyurethane soft foam was prepared according to the preparation method of step (3) in Example 1.

[0077] Example 8

[0078] (1) Preparation of vegetable oil polyols: Epoxidized soybean oil (10 g, epoxy value 6.2%, epoxy group 38.4 mmol) and fluoroboric acid (20 mg, 50 wt.%) were mixed to obtain a first mixed solution; dilaurin (8.77 g, 19.2 mmol) was dissolved in ethyl acetate (10 mL) to obtain a second mixed solution; the temperature of the first microreactor was adjusted to 90°C, and the first mixed solution and the second mixed solution were simultaneously pumped into the first microreactor (15 mL) of a microchannel reaction device at a rate of 2 mL / min and 3 mL / min, respectively, for a ring-opening reaction to obtain a first reaction solution.

[0079] (2) 8-Hydroxyoctanoic acid ethyl ester (2.89 g, 15.4 mmol) was dissolved in ethyl acetate (20 mL) to obtain a third mixed solution; the temperature of the second microreactor was adjusted to 90° C., and the third mixed solution and the first reaction solution obtained in step (1) were simultaneously pumped into the second microreactor (20 mL) of the microchannel reaction device at a rate of 5 mL / min for a ring-opening reaction to obtain a second reaction solution; after the reaction was completed, the reaction solution was washed with sodium bicarbonate solution (30 mL, 10 wt.%) and water (30 mL×2) in sequence, and the organic phase was dried and concentrated to obtain soybean oil polyol with a hydroxyl value of 66 mg KOH / g, an epoxy value of 0.3, and a viscosity of 321 mPa·s.

[0080] (3) Preparation of plant oil-based polyurethane soft foam: Bio-based polyurethane soft foam was prepared according to the preparation method of step (3) in Example 1.

[0081] Example 9

[0082] (1) Preparation of vegetable oil polyols: Epoxidized soybean oil (10 g, epoxy value 6.2%, epoxy group 38.4 mmol) and fluoroboric acid (20 mg, 50 wt.%) were mixed to obtain a first mixed solution; dilaurin (8.77 g, 19.2 mmol) was dissolved in ethyl acetate (10 mL) to obtain a second mixed solution; the temperature of the first microreactor was adjusted to 90°C, and the first mixed solution and the second mixed solution were simultaneously pumped into the first microreactor (10 mL) of a microchannel reaction device at a rate of 0.5 mL / min and 0.7 mL / min, respectively, for a ring-opening reaction to obtain a first reaction solution.

[0083] (2) 8-Hydroxyoctanoic acid ethyl ester (2.89 g, 15.4 mmol) was dissolved in ethyl acetate (20 mL) to obtain a third mixed solution; the temperature of the second microreactor was adjusted to 90° C., and the third mixed solution and the first reaction solution obtained in step (1) were simultaneously pumped into the second microreactor (15 mL) of the microchannel reaction device at a rate of 1.3 mL / min for a ring-opening reaction to obtain a second reaction solution; after the reaction was completed, the reaction solution was washed with sodium bicarbonate solution (30 mL, 10 wt.%) and water (30 mL×2) in sequence, and the organic phase was dried and concentrated to obtain soybean oil polyol with a hydroxyl value of 84 mg KOH / g, an epoxy value of 0.3, and a viscosity of 606 mPa·s.

[0084] (3) Preparation of plant oil-based polyurethane soft foam: Bio-based polyurethane soft foam was prepared according to the preparation method of step (3) in Example 1.

[0085] Example 10

[0086] (1) Preparation of vegetable oil polyols: Epoxidized soybean oil (10 g, epoxy value 6.2%, epoxy group 38.4 mmol) and fluoroboric acid (20 mg, 50 wt.%) were mixed to obtain a first mixed solution; dioleyl glycerol (11.92 g, 19.2 mmol) was dissolved in ethyl acetate (10 mL) to obtain a second mixed solution; the temperature of the first microreactor was adjusted to 90°C, and the first mixed solution and the second mixed solution were simultaneously pumped into the first microreactor (15 mL) of a microchannel reaction device at a rate of 1 mL / min and 1.6 mL / min, respectively, for a ring-opening reaction to obtain a first reaction solution.

[0087] (2) 8-Hydroxyoctanoic acid ethyl ester (2.89 g, 15.4 mmol) was dissolved in ethyl acetate (20 mL) to obtain a third mixed solution; the temperature of the second microreactor was adjusted to 90° C., and the third mixed solution and the first reaction solution obtained in step (1) were simultaneously pumped into the second microreactor (20 mL) of the microchannel reaction device at a rate of 2.6 mL / min for a ring-opening reaction to obtain a second reaction solution; after the reaction was completed, the reaction solution was washed with sodium bicarbonate solution (30 mL, 10 wt.%) and water (30 mL×2) in sequence, and the organic phase was dried and concentrated to obtain soybean oil polyol with a hydroxyl value of 68 mg KOH / g, an epoxy value of 0.2, and a viscosity of 308 mPa·s.

[0088] (3) Preparation of plant oil-based polyurethane soft foam: Bio-based polyurethane soft foam was prepared according to the preparation method of step (3) in Example 1.

[0089] Example 11

[0090] (1) Preparation of vegetable oil polyols: Epoxidized soybean oil (10 g, epoxy value 6.2%, epoxy group 38.4 mmol) and fluoroboric acid (20 mg, 50 wt.%) were mixed to obtain a first mixed solution; distearic acid glyceryl (12 g, 19.2 mmol) was dissolved in ethyl acetate (10 mL) to obtain a second mixed solution; the temperature of the first microreactor was adjusted to 90°C, and the first mixed solution and the second mixed solution were simultaneously pumped into the first microreactor (15 mL) of a microchannel reaction device at a rate of 1 mL / min and 1.6 mL / min, respectively, for a ring-opening reaction to obtain a first reaction solution.

[0091] (2) 8-Hydroxyoctanoic acid ethyl ester (2.89 g, 15.4 mmol) was dissolved in ethyl acetate (20 mL) to obtain a third mixed solution; the temperature of the second microreactor was adjusted to 90° C., and the third mixed solution and the first reaction solution obtained in step (1) were simultaneously pumped into the second microreactor (20 mL) of the microchannel reaction device at a rate of 2.6 mL / min for a ring-opening reaction to obtain a second reaction solution; after the reaction was completed, the reaction solution was washed with sodium bicarbonate solution (30 mL, 10 wt.%) and water (30 mL×2) in sequence, and the organic phase was dried and concentrated to obtain soybean oil polyol with a hydroxyl value of 66 mg KOH / g, an epoxy value of 0.2, and a viscosity of 311 mPa·s.

[0092] (3) Preparation of plant oil-based polyurethane soft foam: Bio-based polyurethane soft foam was prepared according to the preparation method of step (3) in Example 1.

[0093] Example 12

[0094] (1) Preparation of vegetable oil polyols: Epoxidized soybean oil (10 g, epoxy value 6.2%, epoxy group 38.4 mmol) and fluoroboric acid (20 mg, 50 wt.%) were mixed to obtain a first mixed solution; dilaurin (8.77 g, 19.2 mmol) was dissolved in ethyl acetate (10 mL) to obtain a second mixed solution; the temperature of the first microreactor was adjusted to 90°C, and the first mixed solution and the second mixed solution were simultaneously pumped into the first microreactor (15 mL) of a microchannel reaction device at a rate of 1 mL / min and 1.5 mL / min, respectively, for a ring-opening reaction to obtain a first reaction solution.

[0095] (2) Ethyl 4-hydroxybutyrate (2.04 g, 15.4 mmol) was dissolved in ethyl acetate (20 mL) to obtain a third mixed solution; the temperature of the second microreactor was adjusted to 90° C., and the third mixed solution and the first reaction solution obtained in step (1) were simultaneously pumped into the second microreactor (20 mL) of the microchannel reaction device at a rate of 2.5 mL / min for a ring-opening reaction to obtain a second reaction solution; after the reaction was completed, the reaction solution was washed with sodium bicarbonate solution (30 mL, 10 wt.%) and water (30 mL×2) in sequence, and the organic phase was dried and concentrated to obtain soybean oil polyol with a hydroxyl value of 84 mg KOH / g, an epoxy value of 0.3, and a viscosity of 586 mPa·s.

[0096] (3) Preparation of plant oil-based polyurethane soft foam: Bio-based polyurethane soft foam was prepared according to the preparation method of step (3) in Example 1.

[0097] Example 13

[0098] (1) Preparation of vegetable oil polyols: Epoxidized soybean oil (10 g, epoxy value 6.2%, epoxy group 38.4 mmol) and fluoroboric acid (20 mg, 50 wt.%) were mixed to obtain a first mixed solution; dilaurin (8.77 g, 19.2 mmol) was dissolved in ethyl acetate (10 mL) to obtain a second mixed solution; the temperature of the first microreactor was adjusted to 90°C, and the first mixed solution and the second mixed solution were simultaneously pumped into the first microreactor (15 mL) of a microchannel reaction device at a rate of 1 mL / min and 1.5 mL / min, respectively, for a ring-opening reaction to obtain a first reaction solution.

[0099] (2) 6-hydroxyhexanoic acid methyl ester (2.25 g, 15.4 mmol) was dissolved in ethyl acetate (20 mL) to obtain a third mixed solution; the temperature of the second microreactor was adjusted to 90° C., and the third mixed solution and the first reaction solution obtained in step (1) were simultaneously pumped into the second microreactor (20 mL) of the microchannel reaction device at a rate of 2.5 mL / min for a ring-opening reaction to obtain a second reaction solution; after the reaction was completed, the reaction solution was washed with sodium bicarbonate solution (30 mL, 10 wt.%) and water (30 mL×2) in sequence, and the organic phase was dried and concentrated to obtain soybean oil polyol with a hydroxyl value of 82 mg KOH / g, an epoxy value of 0.3, and a viscosity of 509 mPa·s.

[0100] (3) Preparation of plant oil-based polyurethane soft foam: Bio-based polyurethane soft foam was prepared according to the preparation method of step (3) in Example 1.

[0101] Example 14

[0102] (1) Preparation of vegetable oil polyols: Epoxidized soybean oil (10 g, epoxy value 6.2%, epoxy group 38.4 mmol) and fluoroboric acid (20 mg, 50 wt.%) were mixed to obtain a first mixed solution; dilaurin (8.77 g, 19.2 mmol) was dissolved in ethyl acetate (10 mL) to obtain a second mixed solution; the temperature of the first microreactor was adjusted to 90°C, and the first mixed solution and the second mixed solution were simultaneously pumped into the first microreactor (15 mL) of a microchannel reaction device at a rate of 1 mL / min and 1.5 mL / min, respectively, for a ring-opening reaction to obtain a first reaction solution.

[0103] (2) 10-hydroxydecanoic acid methyl ester (3.12 g, 15.4 mmol) was dissolved in ethyl acetate (20 mL) to obtain a third mixed solution; the temperature of the second microreactor was adjusted to 90° C., and the third mixed solution and the first reaction solution obtained in step (1) were simultaneously pumped into the second microreactor (20 mL) of the microchannel reaction device at a rate of 2.5 mL / min for a ring-opening reaction to obtain a second reaction solution; after the reaction was completed, the reaction solution was washed with sodium bicarbonate solution (30 mL, 10 wt.%) and water (30 mL×2) in sequence, and the organic phase was dried and concentrated to obtain soybean oil polyol with a hydroxyl value of 79 mg KOH / g, an epoxy value of 0.3, and a viscosity of 452 mPa·s.

[0104] (3) Preparation of plant oil-based polyurethane soft foam: Bio-based polyurethane soft foam was prepared according to the preparation method of step (3) in Example 1.

[0105] Example 15

[0106] (1) Preparation of vegetable oil polyols: Epoxidized cottonseed oil (12.05 g, epoxy value 5.1%, epoxy group 38.4 mmol) and fluoroboric acid (20 mg, 50 wt.%) were mixed to obtain a first mixed solution; dilaurin (8.77 g, 19.2 mmol) was dissolved in ethyl acetate (10 mL) to obtain a second mixed solution; the temperature of the first microreactor was adjusted to 90°C, and the first mixed solution and the second mixed solution were simultaneously pumped into the first microreactor (15 mL) of a microchannel reaction device at a rate of 1.3 mL / min and 1.5 mL / min, respectively, for a ring-opening reaction to obtain a first reaction solution.

[0107] (2) 8-Hydroxyoctanoic acid ethyl ester (2.89 g, 15.4 mmol) was dissolved in ethyl acetate (20 mL) to obtain a third mixed solution; the temperature of the second microreactor was adjusted to 90° C., and the third mixed solution and the first reaction solution obtained in step (1) were simultaneously pumped into the second microreactor (20 mL) of the microchannel reaction device at a rate of 2.8 mL / min for a ring-opening reaction to obtain a second reaction solution; after the reaction was completed, the reaction solution was washed with sodium bicarbonate solution (30 mL, 10 wt.%) and water (30 mL×2) in sequence, and the organic phase was dried and concentrated to obtain cottonseed oil polyol with a hydroxyl value of 72 mg KOH / g, an epoxy value of 0.3, and a viscosity of 425 mPa·s.

[0108] (3) Preparation of plant oil-based polyurethane soft foam: Bio-based polyurethane soft foam was prepared according to the preparation method of step (3) in Example 1.

[0109] Example 16

[0110] (1) Preparation of vegetable oil polyols: Epoxidized sunflower oil (10.2 g, epoxy value 6.0%, epoxy group 38.2 mmol) and fluoroboric acid (20 mg, 50 wt.%) were mixed to obtain a first mixed solution; dilaurin (8.77 g, 19.2 mmol) was dissolved in ethyl acetate (10 mL) to obtain a second mixed solution; the temperature of the first microreactor was adjusted to 90°C, and the first mixed solution and the second mixed solution were simultaneously pumped into the first microreactor (15 mL) of a microchannel reaction device at a rate of 1 mL / min and 1.5 mL / min, respectively, for a ring-opening reaction to obtain a first reaction solution.

[0111] (2) 8-hydroxyoctanoic acid ethyl ester (2.89 g, 15.4 mmol) was dissolved in ethyl acetate (20 mL) to obtain a third mixed solution; the temperature of the second microreactor was adjusted to 90° C., and the third mixed solution and the first reaction solution obtained in step (1) were simultaneously pumped into the second microreactor (20 mL) of the microchannel reaction device at a rate of 2.5 mL / min for a ring-opening reaction to obtain a second reaction solution; after the reaction was completed, the reaction solution was washed with sodium bicarbonate solution (30 mL, 10 wt.%) and water (30 mL×2) in sequence, and the organic phase was dried and concentrated to obtain a sunflower oil polyol with a hydroxyl value of 79 mg KOH / g, an epoxy value of 0.3, and a viscosity of 467 mPa·s.

[0112] (3) Preparation of plant oil-based polyurethane soft foam: Bio-based polyurethane soft foam was prepared according to the preparation method of step (3) in Example 1.

[0113] Example 17

[0114] (1) Preparation of vegetable oil polyols: Epoxidized rapeseed oil (12.6 g, epoxy value 4.9%, epoxy group 38.4 mmol) and fluoroboric acid (20 mg, 50 wt.%) were mixed to obtain a first mixed solution; dilaurin (8.77 g, 19.2 mmol) was dissolved in ethyl acetate (10 mL) to obtain a second mixed solution; the temperature of the first microreactor was adjusted to 90°C, and the first mixed solution and the second mixed solution were simultaneously pumped into the first microreactor (15 mL) of a microchannel reaction device at a rate of 1.4 mL / min and 1.5 mL / min, respectively, for a ring-opening reaction to obtain a first reaction solution.

[0115] (2) 8-hydroxyoctanoic acid ethyl ester (2.89 g, 15.4 mmol) was dissolved in ethyl acetate (20 mL) to obtain a third mixed solution; the temperature of the second microreactor was adjusted to 90° C., and the third mixed solution and the first reaction solution obtained in step (1) were simultaneously pumped into the second microreactor (20 mL) of the microchannel reaction device at a rate of 2.9 mL / min for a ring-opening reaction to obtain a second reaction solution; after the reaction was completed, the reaction solution was washed with sodium bicarbonate solution (30 mL, 10 wt.%) and water (30 mL×2) in sequence, and the organic phase was dried and concentrated to obtain rapeseed oil polyol with a hydroxyl value of 70 mg KOH / g, an epoxy value of 0.2, and a viscosity of 396 mPa·s.

[0116] (3) Preparation of plant oil-based polyurethane soft foam: Bio-based polyurethane soft foam was prepared according to the preparation method of step (3) in Example 1.

[0117] Example 18

[0118] (1) Preparation of vegetable oil polyols: Epoxidized corn oil (11.8 g, epoxy value 5.2%, epoxy group 38.4 mmol) and fluoroboric acid (20 mg, 50 wt.%) were mixed to obtain a first mixed solution; dilaurin (8.77 g, 19.2 mmol) was dissolved in ethyl acetate (10 mL) to obtain a second mixed solution; the temperature of the first microreactor was adjusted to 90°C, and the first mixed solution and the second mixed solution were simultaneously pumped into the first microreactor (15 mL) of a microchannel reaction device at a rate of 1.2 mL / min and 1.5 mL / min, respectively, for a ring-opening reaction to obtain a first reaction solution.

[0119] (2) 8-Hydroxyoctanoic acid ethyl ester (2.89 g, 15.4 mmol) was dissolved in ethyl acetate (20 mL) to obtain a third mixed solution; the temperature of the second microreactor was adjusted to 90° C., and the third mixed solution and the first reaction solution obtained in step (1) were simultaneously pumped into the second microreactor (20 mL) of the microchannel reaction device at a rate of 2.7 mL / min for a ring-opening reaction to obtain a second reaction solution; after the reaction was completed, the reaction solution was washed with sodium bicarbonate solution (30 mL, 10 wt.%) and water (30 mL×2) in sequence, and the organic phase was dried and concentrated to obtain corn oil polyol with a hydroxyl value of 73 mg KOH / g, an epoxy value of 0.3, and a viscosity of 428 mPa·s.

[0120] (3) Preparation of plant oil-based polyurethane soft foam: Bio-based polyurethane soft foam was prepared according to the preparation method of step (3) in Example 1.

[0121] Example 19

[0122] (1) Preparation of vegetable oil polyols: Epoxidized peanut oil (13.7 g, epoxy value 4.5%, epoxy group 38.4 mmol) and fluoroboric acid (20 mg, 50 wt.%) were mixed to obtain a first mixed solution; dilaurin (8.77 g, 19.2 mmol) was dissolved in ethyl acetate (10 mL) to obtain a second mixed solution; the temperature of the first microreactor was adjusted to 90°C, and the first mixed solution and the second mixed solution were simultaneously pumped into the first microreactor (15 mL) of a microchannel reaction device at a rate of 1.4 mL / min and 1.5 mL / min, respectively, for a ring-opening reaction to obtain a first reaction solution.

[0123] (2) 8-Hydroxyoctanoic acid ethyl ester (2.89 g, 15.4 mmol) was dissolved in ethyl acetate (20 mL) to obtain a third mixed solution; the temperature of the second microreactor was adjusted to 90° C., and the third mixed solution and the first reaction solution obtained in step (1) were simultaneously pumped into the second microreactor (20 mL) of the microchannel reaction device at a rate of 2.9 mL / min for a ring-opening reaction to obtain a second reaction solution; after the reaction was completed, the reaction solution was washed with sodium bicarbonate solution (30 mL, 10 wt.%) and water (30 mL×2) in sequence, and the organic phase was dried and concentrated to obtain peanut oil polyol with a hydroxyl value of 67 mg KOH / g, an epoxy value of 0.2, and a viscosity of 379 mPa·s.

[0124] (3) Preparation of plant oil-based polyurethane soft foam: Bio-based polyurethane soft foam was prepared according to the preparation method of step (3) in Example 1.

[0125] Comparative Example 1

[0126] (1) Preparation of vegetable oil polyols: Epoxidized soybean oil (10 g, epoxy value 6.2%, epoxy group 38.4 mmol), fluoroboric acid (20 mg, 50 wt.%), dilaurin (8.77 g, 19.2 mmol) and ethyl acetate (30 mL) were reacted at 90°C for 6 h. Subsequently, 8-hydroxyoctanoic acid ethyl ester (2.89 g, 15.4 mmol) was added to the system and the reaction was continued at 90°C for 4 h. After the reaction was completed, the reaction solution was cooled to room temperature and washed with sodium bicarbonate solution (30 mL, 10 wt.%) and water (30 mL×2) in sequence. The organic phase was dried and concentrated to obtain soybean oil polyol with a hydroxyl value of 42 mg KOH / g, an epoxy value of 0.1 and a viscosity of 1682 mPa·s.

[0127] (2) Preparation of plant oil-based polyurethane soft foam: Bio-based polyurethane soft foam was prepared according to the preparation method of step (3) in Example 1.

[0128] Comparative Example 2

[0129] (1) Preparation of vegetable oil polyols: Epoxidized soybean oil (10 g, epoxy value 6.2%, epoxy group 38.4 mmol) and fluoroboric acid (20 mg, 50 wt.%) were mixed to obtain a first mixed solution; dilaurin (3.52 g, 7.7 mmol) was dissolved in ethyl acetate (10 mL) to obtain a second mixed solution; the temperature of the first microreactor was adjusted to 90°C, and the first mixed solution and the second mixed solution were simultaneously pumped into the first microreactor (15 mL) of a microchannel reaction device at a rate of 1 mL / min and 1.2 mL / min, respectively, for a ring-opening reaction to obtain a first reaction solution.

[0130] (2) 8-hydroxyoctanoic acid ethyl ester (5.06 g, 26.9 mmol) was dissolved in ethyl acetate (20 mL) to obtain a third mixed solution; the temperature of the second microreactor was adjusted to 90° C., and the third mixed solution and the first reaction solution obtained in step (1) were simultaneously pumped into the second microreactor (20 mL) of the microchannel reaction device at a rate of 2.2 mL / min for a ring-opening reaction to obtain a second reaction solution; after the reaction was completed, the reaction solution was washed with sodium bicarbonate solution (30 mL, 10 wt.%) and water (30 mL×2) in sequence, and the organic phase was dried and concentrated to obtain soybean oil polyol with a hydroxyl value of 54 mg KOH / g, an epoxy value of 0.3, and a viscosity of 681 mPa·s.

[0131] (3) Preparation of plant oil-based polyurethane soft foam: Bio-based polyurethane soft foam was prepared according to the preparation method of step (3) in Example 1.

[0132] Comparative Example 3

[0133] (1) Preparation of vegetable oil polyols: Epoxidized soybean oil (10 g, epoxy value 6.2%, epoxy group 38.4 mmol) and fluoroboric acid (20 mg, 50 wt.%) were mixed to obtain a first mixed solution; dilaurin (12.29 g, 26.9 mmol) was dissolved in ethyl acetate (10 mL) to obtain a second mixed solution; the temperature of the first microreactor was adjusted to 90°C, and the first mixed solution and the second mixed solution were simultaneously pumped into the first microreactor (15 mL) of a microchannel reaction device at a rate of 1 mL / min and 1.6 mL / min, respectively, for a ring-opening reaction to obtain a first reaction solution.

[0134] (2) 8-Hydroxyoctanoic acid ethyl ester (1.46 g, 7.8 mmol) was dissolved in ethyl acetate (20 mL) to obtain a third mixed solution; the temperature of the second microreactor was adjusted to 90° C., and the third mixed solution and the first reaction solution obtained in step (1) were simultaneously pumped into the second microreactor (20 mL) of the microchannel reaction device at a rate of 2.6 mL / min for a ring-opening reaction to obtain a second reaction solution; after the reaction was completed, the reaction solution was washed with sodium bicarbonate solution (30 mL, 10 wt.%) and water (30 mL×2) in sequence, and the organic phase was dried and concentrated to obtain soybean oil polyol with a hydroxyl value of 60 mg KOH / g, an epoxy value of 0.3, and a viscosity of 1177 mPa·s.

[0135] (3) Preparation of plant oil-based polyurethane soft foam: Bio-based polyurethane soft foam was prepared according to the preparation method of step (3) in Example 1.

[0136] Comparative Example 4

[0137] (1) Preparation of vegetable oil polyols: Epoxidized soybean oil (10 g, epoxy value 6.2%, epoxy group 38.4 mmol) and fluoroboric acid (20 mg, 50 wt.%) were mixed to obtain a first mixed solution; dilaurin (8.77 g, 19.2 mmol) was dissolved in ethyl acetate (10 mL) to obtain a second mixed solution; the temperature of the first microreactor was adjusted to 110°C, and the first mixed solution and the second mixed solution were simultaneously pumped into the first microreactor (15 mL) of a microchannel reaction device at a rate of 1 mL / min and 1.5 mL / min, respectively, for a ring-opening reaction to obtain a first reaction solution.

[0138] (2) 8-Hydroxyoctanoic acid ethyl ester (2.89 g, 15.4 mmol) was dissolved in ethyl acetate (20 mL) to obtain a third mixed solution; the temperature of the second microreactor was adjusted to 110° C., and the third mixed solution and the first reaction solution obtained in step (1) were simultaneously pumped into the second microreactor (20 mL) of the microchannel reaction device at a rate of 2.5 mL / min for a ring-opening reaction to obtain a second reaction solution; after the reaction was completed, the reaction solution was washed with sodium bicarbonate solution (30 mL, 10 wt.%) and water (30 mL×2) in sequence, and the organic phase was dried and concentrated to obtain soybean oil polyol with a hydroxyl value of 57 mg KOH / g, an epoxy value of 0.3, and a viscosity of 1302 mPa·s.

[0139] (3) Preparation of plant oil-based polyurethane soft foam: Bio-based polyurethane soft foam was prepared according to the preparation method of step (3) in Example 1.

[0140] The performance indicators of the bio-based polyurethane flexible foams prepared in Examples 1 to 19 and Comparative Examples 1 to 4 are shown in Tables 1 and 2.

[0141] Table 1 Performance indicators of bio-based polyurethane flexible foams prepared in Examples 1 to 12

[0142]

[0143] Table 2 Performance indicators of bio-based polyurethane flexible foams prepared in Examples 13 to 19 and Comparative Examples 1 to 4

[0144]

[0145] The polyurethane product obtained by the present invention has good tensile properties, that is, high softness, low surface hardness, which can reach 0, and the elastomer product quality is high. However, during the reaction in the reaction bottle or the reaction process in which the amount used exceeds the protection range, there are many cross-linking side reactions, resulting in low quality of the polyurethane product.

[0146] The present invention provides a plant oil polyol, its preparation method, and its application. There are many methods and approaches to implement this technical solution. The above is only a preferred embodiment of the present invention. It should be noted that those skilled in the art may make various improvements and modifications without departing from the principles of the present invention, and such improvements and modifications are also within the scope of protection of the present invention. Any components not specified in this embodiment may be implemented using existing technologies.

Claims

1. A method for preparing vegetable oil polyols, characterized in that: The steps include: (1) mixing epoxidized vegetable oil and an acidic catalyst to obtain a first mixed solution; dissolving diglyceride in an organic solvent to obtain a second mixed solution; and simultaneously pumping the first mixed solution and the second mixed solution into a first microreactor of a microchannel reaction device to perform a first ring-opening reaction to obtain a first reaction solution; (2) dissolving the hydroxycarboxylate in an organic solvent to obtain a third mixed solution; simultaneously pumping the first reaction solution obtained in step (1) and the third mixed solution into a second microreactor of a microchannel reaction device to perform a second ring-opening reaction to obtain a second reaction solution; and after the reaction is completed, post-treating the reaction solution to obtain a vegetable oil polyol; The epoxidized vegetable oil is any one or a combination of epoxidized olive oil, epoxidized peanut oil, epoxidized rapeseed oil, epoxidized cottonseed oil, epoxidized soybean oil, epoxidized coconut oil, epoxidized palm oil, epoxidized sesame oil, epoxidized corn oil and epoxidized sunflower oil; The diglyceride is any one of dilaurin, diolein and distearin, or a combination thereof. The hydroxycarboxylate is any one or a combination of 4-hydroxybutyric acid methyl ester, 4-hydroxybutyric acid ethyl ester, 6-hydroxyhexanoic acid methyl ester, 6-hydroxyhexanoic acid ethyl ester, 8-hydroxyoctanoic acid methyl ester, 8-hydroxyoctanoic acid ethyl ester, 10-hydroxydecanoic acid methyl ester and 10-hydroxydecanoic acid ethyl ester; In step (1), the mass ratio of the acidic catalyst to the epoxidized vegetable oil is 0.02-0.1%:1; the molar ratio of the diglyceride to the epoxy group in the epoxidized vegetable oil is 0.4-0.6:1; and the mass volume ratio of the epoxidized vegetable oil to the organic solvent is 1 g:0.5-2 mL; In step (1), the flow rate of the first mixed liquid pumped into the first microreactor of the microchannel reaction device is 0.5-2 mL / min; the flow rate of the second mixed liquid pumped into the first microreactor of the microchannel reaction device is 0.7-3 mL / min; the volume of the first microreactor is 10-20 mL; the reaction temperature of the first ring-opening reaction is 80-100°C; The molar ratio of the hydroxycarboxylate in step (2) to the epoxy group in the epoxidized vegetable oil in step (1) is 0.3-0.5:1; The mass volume ratio of the epoxidized vegetable oil in step (1) to the organic solvent in step (2) is 1 g: 1-4 mL; In step (2), the flow rate of the first reaction liquid pumped into the second microreactor of the microchannel reaction device is: the sum of the flow rate of the first mixed liquid pumped into the first microreactor of the microchannel reaction device and the flow rate of the second mixed liquid pumped into the first microreactor of the microchannel reaction device in step (1); the flow rate of the third mixed liquid pumped into the second microreactor of the microchannel reaction device is 1-5 mL / min; In step (2), the volume of the second microreactor is 15-25 mL; the reaction temperature of the second ring-opening reaction is 80-100°C.

2. The preparation method according to claim 1, characterized in that The acidic catalyst is any one or a combination of fluoroboric acid, concentrated sulfuric acid, p-toluenesulfonic acid, methanesulfonic acid and benzenesulfonic acid; in step (1) and step (2), the organic solvent is any one or a combination of ethyl acetate, dichloromethane, dichloroethane, chloroform, n-hexane, tetrahydrofuran, 1,4-dioxane, carbon tetrachloride, toluene and xylene.

3. The preparation method according to claim 1, characterized in that The microchannel reaction device includes a first feed pump, a second feed pump, a third feed pump, a microreaction pipeline, a first micromixer, a second micromixer, a first microreactor, a second microreactor and a receiver; the first feed pump and the second feed pump are connected to the first micromixer in parallel through pipelines; the first micromixer is connected to the first microreactor through a pipeline; the first microreactor and the third feed pump are connected to the second micromixer in parallel through pipelines; the second micromixer, the second microreactor and the receiver are connected in series in sequence through pipelines.

4. The vegetable oil polyol prepared by the preparation method according to any one of claims 1 to 3.

5. Use of the vegetable oil polyol according to claim 4 in the preparation of bio-based polyurethane flexible foam.

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