Vegetable oil polyol and preparation method thereof

Abstract

The invention discloses vegetable oil polyol and a preparation method thereof, and belongs to the technical field of chemical materials and production thereof. The method comprises the following steps: mixing epoxy vegetable oil with an acid catalyst to obtain a first mixed solution, mixing a ring-opening reagent with an organic solvent to obtain a second mixed solution, and then pumping the first mixed solution and the second mixed solution into a micro-mixer in a micro-channel reaction device for mixing to obtain a mixed solution; feeding the mixed solution into a microreactor in a microchannel reaction device to carry out ring-opening reaction, collecting by a receiver in the microchannel reaction device to obtain a vegetable oil polyol reaction solution, and finally carrying out post-treatment on the vegetable oil polyol reaction solution to obtain the vegetable oil polyol. The simple ring-opening reagent is adopted, the micro-mixer is improved in the process, mixing is promoted, the problem that liquid-liquid mass transfer is difficult in the ring-opening process is solved, and the ring-opening reaction is conducted more thoroughly.

Description

Technical Field

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

[0002] The development of vegetable oil polyols is considered an effective way to develop bio-based materials. As an important monomer of bio-based polyurethane materials, it is derived from vegetable oil as a raw material through chemical modification of the molecular structure. It is an important renewable resource. It reacts with isocyanate compounds to form polyurethane. It is a good substitute for petroleum-based polyols and a breakthrough in the development of bio-based polyurethane coatings. Vegetable oil is oxidized to epoxy vegetable oil, and then polyhydroxy compounds are generated through reactions such as ring opening. This scheme has high atomic economy and has the advantages of flexibility, structural controllability and molecular diversity. It has become the main method for developing bio-based polyols.

[0003] The reaction mass transfer process between vegetable oil macromolecules and reaction reagents is often severely restricted by the liquid-liquid two-phase structure, resulting in low reaction efficiency, high material consumption, heavy emissions and other problems. The existing technology generally achieves certain progress through continuous flow reaction, but there are still some technical defects, which makes it difficult to control product quality and high cost. Summary of the invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to propose a vegetable oil polyol and a preparation method thereof, the micro-mixer is improved by using microchannel technology, rotatable blades are added to the mixing channel, and a trumpet-shaped orifice and a screen are set at the outlet, which promotes the mixing of the two phases and better performs the ring-opening reaction.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] The first aspect of the present invention is to provide a method for preparing vegetable oil polyols, comprising the following steps:

[0007] S1: mixing the epoxidized vegetable oil and the acidic catalyst to obtain a first mixed solution;

[0008] S2: mixing the ring-opening reagent and the organic solvent to obtain a second mixed solution;

[0009] S3: pumping the first mixed solution and the second mixed solution into a micro mixer in the microchannel reaction device to mix them to obtain a mixed solution;

[0010] S4: sending the mixed solution into a microreactor in a microchannel reaction device to perform a ring-opening reaction, and collecting the vegetable oil polyol reaction solution through a receiver in the microchannel reaction device;

[0011] S5: post-treating the vegetable oil polyol reaction solution to obtain the vegetable oil polyol.

[0012] Preferably, the micromixer is a Y-type mixer, which consists of two inlets, a mixing channel and an outlet.

[0013] Preferably, an element is provided in the middle of the mixing channel, the element includes a connecting rod and blades, one side of the connecting rod is connected to the pipe wall in the mixing channel, and the other side is connected to the blades; the blades expand outward to both sides with the top of the connecting rod as the midpoint, and the total length of the blades is consistent with the diameter of the pipe in the mixing channel; the element can rotate with the fluid and is used to stir the liquid.

[0014] Preferably, the outlet is provided with a trumpet-shaped orifice for spraying outwards, and the orifice is provided with a screen; the outlet is used to spray the fluid out.

[0015] Preferably, the epoxidized vegetable oil is selected from at least one 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 acidic catalyst is selected from at least one of fluoroboric acid, concentrated sulfuric acid, p-toluenesulfonic acid, methanesulfonic acid and benzenesulfonic acid; the mass percentage of the epoxidized vegetable oil to the acidic catalyst is 1:0.2-1.2%.

[0016] More preferably, the epoxidized vegetable oil is epoxidized soybean oil, the acidic catalyst is fluoroboric acid, and the mass percentage of the epoxidized vegetable oil to the acidic catalyst is 1:0.2%.

[0017] Preferably, the ring-opening reagent is a simple primary alcohol, selected from at least one of methanol or ethanol; the organic solvent is at least one of ethyl acetate, dichloromethane, dichloroethane, chloroform, n-hexane, tetrahydrofuran, 1,4-dioxane, carbon tetrachloride, toluene and xylene; the mass volume ratio of the ring-opening reagent to the organic solvent is 1g:0.5-2mL.

[0018] More preferably, the organic solvent is dichloromethane, and the mass volume ratio of the ring-opening reagent to the organic solvent is 1 g:1.2-1.6 mL.

[0019] Preferably, the molar ratio of epoxy groups to ring-opening reagents in the epoxidized vegetable oil is 1:0.5-0.6.

[0020] Preferably, the ring-opening reaction temperature in S4 is 60-100° C., and the ring-opening reaction residence time is 3-15 min.

[0021] More preferably, the ring-opening reaction temperature is 80° C. and the ring-opening reaction residence time is 10 min.

[0022] Preferably, the microchannel reaction device comprises a connecting pipeline, a first feed pump, a second feed pump, a micromixer, a microreactor and a receiver; the first feed pump and the second feed pump are connected to the micromixer in parallel through pipelines; the micromixer, the microreactor and the receiver are connected in series in sequence through pipelines; the volume of the microreactor is 5-15mL.

[0023] More preferably, the volume of the microreactor is 10 mL.

[0024] The second aspect of the present invention is to provide a vegetable oil polyol prepared by the above preparation method.

[0025] It should be noted that in S5, the vegetable oil polyol reaction liquid is post-treated, including liquid separation, organic base neutralization, secondary liquid separation, organic phase rotary evaporation, drying and other steps.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The present invention adopts a simple ring-opening reagent, improves the micro-mixer during the process, promotes mixing, improves the problem of difficult liquid-liquid mass transfer during the ring-opening process, makes the ring-opening reaction more thorough, increases the hydroxyl value of the polyol, and improves the quality of the vegetable oil polyol. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Schematic diagram of the microchannel reaction device of the present invention. DETAILED DESCRIPTION

[0029] The present invention will be further described in detail below in conjunction with the accompanying drawings. The embodiments described with reference to the accompanying drawings are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention.

[0030] Figure 1 The schematic diagram of the microchannel reaction device of the present invention is shown in FIG. 1 , wherein the microchannel reaction device comprises a connecting pipeline, a first feed pump, a second feed pump, a micromixer, a microreactor and a receiver; the first feed pump and the second feed pump are connected to the micromixer in parallel through pipelines; the micromixer is connected in series with the microreactor and the receiver in sequence through pipelines.

[0031] Among them, the micro mixer is a Y-type mixer, which consists of two inlets, a mixing channel and an outlet. An element is provided in the middle of the mixing channel, and the element includes a connecting rod and a blade. One side of the connecting rod is connected to the pipe wall in the mixing channel, and the other side is connected to the blade; the blade expands outward to both sides with the top of the connecting rod as the midpoint, and the total length of the blade is consistent with the diameter of the pipe in the mixing channel; the element can rotate with the fluid and is used to stir the liquid; the outlet is provided with a trumpet-shaped orifice for outward spraying, and the orifice is provided with a screen; the outlet is used to spray the fluid out.

[0032] Example 1

[0033] 100 g of epoxidized soybean oil (epoxy value 6.0%) and fluoroboric acid aqueous solution (200 mg, 50 wt%) were mixed to obtain a first mixed solution; 6 g of methanol was dissolved in 8.4 mL of dichloromethane to obtain a second mixed solution.

[0034] The temperature of the oil bath was adjusted to 65°C, and the first mixed liquid and the second mixed liquid were pumped into the Y-type micromixer of the microchannel reaction device at a liquid feeding rate of 0.89 mL / min and a liquid feeding rate of 0.11 mL / min, respectively, for mixing. After being stirred by the elements in the mixing channel, they were ejected from the outlet and entered the microreactor for a ring-opening reaction. After the reaction was completed, a vegetable oil polyol reaction liquid was obtained.

[0035] The vegetable oil polyol reaction liquid was separated, the organic phase was neutralized and washed with a 10wt% sodium bicarbonate aqueous solution to a pH value of 6.5-7.5, the organic phase was separated, and the organic phase was rotary evaporated and dried to obtain soybean oil polyol, whose hydroxyl value was 267mg KOH / g and viscosity was 1392mPa·s.

[0036] Example 2

[0037] 100 g of epoxidized soybean oil (epoxy value: 6.2%) and aqueous fluoroboric acid solution (200 mg, 50 wt%) were mixed to obtain a first mixed solution; 9.5 g of ethanol was dissolved in 13.3 mL of dichloromethane to obtain a second mixed solution.

[0038] The temperature of the oil bath was adjusted to 65°C, and the first mixed liquid and the second mixed liquid were pumped into the Y-type micromixer of the microchannel reaction device at a liquid feeding rate of 0.85 mL / min and a liquid feeding rate of 0.15 mL / min, respectively, for mixing. After being stirred by the elements in the mixing channel, they were ejected from the outlet and entered the microreactor for a ring-opening reaction. After the reaction was completed, a vegetable oil polyol reaction liquid was obtained.

[0039] The vegetable oil polyol reaction liquid was separated, the organic phase was neutralized and washed with a 10wt% sodium bicarbonate aqueous solution to a pH value of 6.5-7.5, separated, and the organic phase was rotary evaporated and dried to obtain soybean oil polyol with a hydroxyl value of 274mg KOH / g and a viscosity of 1445mPa·s.

[0040] Example 3

[0041] 100 g of epoxidized soybean oil (epoxy value 6.5%) and fluoroboric acid aqueous solution (200 mg, 50 wt%) were mixed to obtain a first mixed solution; 10.4 g of ethanol was dissolved in 14.56 mL of dichloromethane to obtain a second mixed solution.

[0042] The temperature of the oil bath was adjusted to 65°C, and the first mixed liquid and the second mixed liquid were pumped into the Y-type micromixer of the microchannel reaction device at a liquid feeding rate of 0.83 mL / min and a liquid feeding rate of 0.17 mL / min, respectively, for mixing. After being stirred by the elements in the mixing channel, they were ejected from the outlet and entered the microreactor for a ring-opening reaction. After the reaction was completed, a vegetable oil polyol reaction liquid was obtained.

[0043] The vegetable oil polyol reaction liquid was separated, the organic phase was neutralized and washed with a 10wt% sodium bicarbonate aqueous solution to a pH value of 6.5-7.5, separated, and the organic phase was rotary evaporated and dried to obtain soybean oil polyol with a hydroxyl value of 291mg KOH / g and a viscosity of 1523mPa·s.

[0044] Example 4

[0045] 100 g of epoxidized soybean oil (epoxy value: 6.7%) and aqueous fluoroboric acid solution (200 mg, 50 wt%) were mixed to obtain a first mixed solution; 8.1 g of methanol was dissolved in 11.34 mL of dichloromethane to obtain a second mixed solution.

[0046] The temperature of the oil bath was adjusted to 65°C, and the first mixed liquid and the second mixed liquid were pumped into the Y-type micromixer of the microchannel reaction device at a liquid feeding rate of 0.87 mL / min and a liquid feeding rate of 0.13 mL / min, respectively, for mixing. After being stirred by the elements in the mixing channel, they were ejected from the outlet and entered the microreactor for a ring-opening reaction. After the reaction was completed, a vegetable oil polyol reaction effluent was obtained.

[0047] The vegetable oil polyol reaction liquid was separated, the organic phase was neutralized and washed with a 10wt% sodium bicarbonate aqueous solution to a pH value of 6.5-7.5, separated, and the organic phase was rotary evaporated and dried to obtain soybean oil polyol with a hydroxyl value of 315mg KOH / g and a viscosity of 1597mPa·s.

[0048] Comparative Example 1

[0049] 100 g of epoxidized soybean oil (epoxy value 6.0%) and fluoroboric acid aqueous solution (200 mg, 50 wt%) were mixed to obtain a first mixed solution; 6 g of methanol was dissolved in 8.4 mL of dichloromethane to obtain a second mixed solution.

[0050] The temperature of the oil bath was adjusted to 65° C. The first mixed solution and the second mixed solution were simultaneously pumped into the microreactor at an inlet rate of 0.89 mL / min and 0.11 mL / min, respectively, to perform a ring-opening reaction. After the reaction was completed, a reaction effluent was obtained.

[0051] The reaction effluent was separated, the organic phase was neutralized and washed with a 10 wt % sodium bicarbonate aqueous solution to a pH of 6.5-7.5, separated, and the organic phase was rotary evaporated and dried to obtain soybean oil polyol with a hydroxyl value of 233 mg KOH / g and a viscosity of 1446 mPa·s.

[0052] Comparative Example 2

[0053] 100 g of epoxidized soybean oil (epoxy value: 6.7%) and aqueous fluoroboric acid solution (200 mg, 50 wt%) were mixed to obtain a first mixed solution; 8.1 g of methanol was dissolved in 11.34 mL of dichloromethane to obtain a second mixed solution.

[0054] The temperature of the oil bath was adjusted to 65° C., and the first mixed solution and the second mixed solution were simultaneously pumped into the microreactor at an inlet rate of 0.87 mL / min and an inlet rate of 0.13 mL / min, respectively, to perform a ring-opening reaction. After the reaction was completed, a reaction effluent was obtained.

[0055] The reaction effluent was separated, and the organic phase was neutralized and washed with a 10 wt % sodium bicarbonate aqueous solution to a pH of 6.5-7.5, separated, and the organic phase was rotary evaporated and dried to obtain soybean oil polyol with a hydroxyl value of 270 mg KOH / g and a viscosity of 1712 mPa·s.

[0056] Product performance test results

[0057] The performance indicators of the vegetable oil polyols prepared in Examples 1-4 and Comparative Examples 1-2 are shown in Table 1.

[0058] Table 1 Performance indicators of vegetable oil polyols

[0059]

[0060] From the data of Comparative Example 1 and Example 1, and Comparative Example 2 and Example 4 in Table 1, it can be seen that the comparative examples did not use a micromixer. Under the same other conditions, the hydroxyl value decreased significantly, the viscosity was high, and the side reaction was serious, indicating that the new improved micromixer provided by the present invention can promote mixing, improve the problem of difficult liquid-liquid mass transfer during the ring-opening process, make the ring-opening reaction more thorough, and improve the quality of vegetable oil polyols.

[0061] The above are only some embodiments of the present invention. For those skilled in the art, several modifications and improvements can be made without departing from the creative concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A method for preparing vegetable oil polyols, characterized in that: The following steps are involved: S1: mixing the epoxidized vegetable oil and the acidic catalyst to obtain a first mixed solution; S2: mixing the ring-opening reagent and the organic solvent to obtain a second mixed solution; S3: pumping the first mixed solution and the second mixed solution into a micro mixer in the microchannel reaction device to mix them to obtain a mixed solution; S4: sending the mixed solution into a microreactor in a microchannel reaction device to perform a ring-opening reaction, and collecting the vegetable oil polyol reaction solution through a receiver in the microchannel reaction device; S5: post-treating the vegetable oil polyol reaction solution to obtain the vegetable oil polyol.

2. The preparation method according to claim 1, characterized in that: The micro mixer is a Y-type mixer, which consists of two inlets, a mixing channel and an outlet.

3. The preparation method according to claim 2, characterized in that: An element is provided in the middle of the mixing channel, the element includes a connecting rod and a blade, one side of the connecting rod is connected to the pipe wall in the mixing channel, and the other side is connected to the blade; the blade expands outward to both sides with the top of the connecting rod as the midpoint, and the total length of the blade is consistent with the diameter of the pipe in the mixing channel; the element can rotate with the fluid and is used to stir the liquid.

4. The preparation method according to claim 2, characterized in that: The outlet is provided with a trumpet-shaped orifice for spraying outwards, and the orifice is provided with a screen; the outlet is used to spray the fluid out.

5. The preparation method according to claim 1, characterized in that: The epoxidized vegetable oil is selected from at least one 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 acidic catalyst is selected from at least one of fluoroboric acid, concentrated sulfuric acid, p-toluenesulfonic acid, methanesulfonic acid and benzenesulfonic acid; the mass percentage of the epoxidized vegetable oil to the acidic catalyst is 1:0.2-1.2%.

6. The preparation method according to claim 5, characterized in that: The ring-opening reagent is a simple primary alcohol, selected from at least one of methanol or ethanol; the organic solvent is at least one of ethyl acetate, dichloromethane, dichloroethane, chloroform, n-hexane, tetrahydrofuran, 1,4-dioxane, carbon tetrachloride, toluene and xylene; the mass volume ratio of the ring-opening reagent to the organic solvent is 1g:0.5-2mL.

7. The preparation method according to claim 6, characterized in that: The molar ratio of the epoxy group in the epoxidized vegetable oil to the ring-opening reagent is 1:0.5-0.

6.

8. The preparation method according to claim 1, characterized in that: In S4, the ring-opening reaction temperature is 60-100° C., and the ring-opening reaction residence time is 3-15 min.

9. The preparation method according to claim 1, characterized in that: The microchannel reaction device comprises a connecting pipeline, a first feed pump, a second feed pump, a micro mixer, a micro reactor and a receiver; the first feed pump and the second feed pump are connected to the micro mixer in parallel through pipelines; the micro mixer, the micro reactor and the receiver are connected in series in sequence through pipelines; the volume of the micro reactor is 5-15 mL.

10. A vegetable oil polyol prepared according to the preparation method according to any one of claims 1 to 9.

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