A bio-based monomer, its preparation method and application

Abstract

This invention belongs to the field of adhesive synthesis technology, and relates to a bio-based monomer, its preparation method, and its application. Itaconic anhydride and eugenol undergo an esterification reaction under the action of an alkaline catalyst to obtain a bio-based monomer composition; the bio-based monomer composition is a mixture of compounds shown in Formula I and Formula II. The carboxyl group in the structure of the bio-based monomer composition is used to ring-open the epoxy group in the structure of an epoxidized vegetable oil to obtain a vegetable oil polyol eugenol ester. The vegetable oil polyol eugenol ester, an active diluent, and a photoinitiator are used to prepare a bio-based adhesive. The adhesive provided by this invention utilizes a bio-based monomer with a specific structure to react with an epoxidized vegetable oil, and with specific amounts of components, achieves good interaction, developing green materials based on renewable biomass resources.

Description

Technical Field

[0001] This invention belongs to the field of adhesive synthesis technology, and relates to a bio-based monomer, its preparation method and application. Background Technology

[0002] With increasingly stringent environmental regulations and the gradual depletion of petroleum resources, the development of green materials based on renewable biomass resources has become a research hotspot in the field of materials science. Epoxy resin adhesives are widely used due to their excellent bonding properties, mechanical properties, and chemical resistance. However, traditional epoxy resin adhesives mostly rely on petroleum-based raw materials such as bisphenol A, and the preparation process often suffers from problems such as long reaction cycles, high energy consumption, and poor safety.

[0003] Photocuring technology, with its advantages of fast curing speed, low energy consumption, and environmental friendliness, is hailed as a "green technology." Combining photocuring technology with bio-based raw materials to develop high-performance bio-based photocurable resins is of great significance. Itaconic acid is a widely available bio-based platform compound that can be produced on a large scale through bio-fermentation. Its molecular structure, with its unsaturated double bonds and two carboxyl groups, provides abundant reactive sites. Epoxidized soybean oil, as an inexpensive, readily available, and renewable bio-based raw material, has epoxy groups that can be used to introduce photocurable reactive groups. Eugenol, a renewable resource extracted from clove oil, provides excellent mechanical properties due to its rigid aromatic ring structure. While there are reports of preparing photocurable resins by reacting itaconic acid or its derivatives with epoxidized soybean oil, the reaction is usually carried out in a traditional batch reactor, which suffers from low heat and mass transfer efficiency, long reaction time, and poor batch-to-batch product stability. In particular, the ring-opening reaction involving carboxyl and epoxy groups is an exothermic reaction. If not properly controlled in traditional batch production, it can easily lead to local overheating, resulting in increased side reactions, darker product color, or even explosive polymerization and material overflow, which can cause safety problems.

[0004] Chinese Patent Publication No. CN105384912A discloses an itaconic acid-based cyclic silica framework epoxy resin, its preparation method, and its application as a matrix resin in coating preparation. The epoxy resin is an addition product of itaconic acid diglycidyl ester and cyclosiloxane under platinum catalyst catalysis, exhibiting excellent flexibility without significantly reducing material rigidity. While this technology utilizes itaconic acid, a bio-based resource, the synthesis process uses a precious metal platinum catalyst, resulting in high costs. Furthermore, the reaction is carried out in a traditional batch reactor, leading to problems such as low heat transfer efficiency and long reaction time.

[0005] Chinese patent CN119463147A discloses a polyether ester polymer, its preparation method, and its application in sealants. The preparation method involves mixing a polyether polyol with itaconic acid and undergoing an esterification reaction to prepare a polyether ester containing double bonds, followed by a reaction with an alkoxysilane to cap the double bonds. This technology cleverly utilizes the esterification reaction between itaconic acid and the polyether polyol to introduce double-bonded groups into the polymer chain segment. However, this patent primarily focuses on the mechanical properties and high-temperature resistance of the final sealant, without addressing issues such as reaction control and scale-up production during the polymer synthesis process.

[0006] Chinese patent CN118308050A discloses a water-resistant pressure-sensitive adhesive, its preparation method, and its application. The raw materials for its preparation include double-bonded polyethers, double-bonded carboxylic acids (including itaconic acid), and double-bonded crosslinking agents. This technology achieves excellent water resistance by introducing double-bonded polyethers with alkyl side chains. However, the preparation of this pressure-sensitive adhesive using traditional thermosetting or photocuring methods results in an uncontrollable polymerization process and requires improvement in the uniformity of the product structure.

[0007] Chinese patent CN113185408A discloses an ethylene oxide-modified acrylic acid, a low-viscosity polyurethane acrylate, its preparation method, and its application. The patent uses ethylene oxide-modified acrylic acid as a capping agent to cap HDI trimers, avoiding chain extension byproducts generated during conventional resin synthesis, resulting in a more uniform product distribution and lower viscosity. This technology achieves reduced resin viscosity through molecular structure design, but the raw material used is still petroleum-based acrylic acid, with limited bio-based content.

[0008] Regarding the above technical solutions, the existing methods for preparing bio-based photocurable resins still have the following shortcomings: First, the reactions are mostly carried out in traditional batch reactors. The ring-opening reaction between carboxyl and epoxy groups is a strongly exothermic reaction, which is prone to local overheating, leading to increased side reactions, darker product color, and even safety issues such as explosive polymerization and material overflow. Second, the reaction cycle is long and the production efficiency is low. Third, the batch stability of the product is poor, making it difficult to meet the requirements of industrial production.

[0009] Continuous flow reaction technology, as a novel chemical synthesis technique, boasts advantages such as high mass and heat transfer efficiency, precise and controllable reaction conditions, stable product quality, and ease of continuous production and industrial scale-up. It has been widely applied in the synthesis of fine chemicals, pharmaceutical intermediates, and other fields. Applying continuous flow technology to the preparation of bio-based adhesives can overcome many drawbacks of traditional batch reactors, enabling efficient and green preparation of adhesives. Summary of the Invention

[0010] The technical problem to be solved by this invention is to address the shortcomings of existing bio-based adhesive synthesis methods, such as long reaction time, low heat transfer efficiency, high operational risks, and poor batch stability of products. This invention provides a bio-based monomer, its preparation method and application, and further provides a safe, efficient, and controllable method for rapid synthesis of itaconic acid-based epoxy resin adhesives.

[0011] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0012] This invention discloses a bio-based monomer composition, which is a mixture of compounds represented by Formula I and Formula II:

[0013] .

[0014] In some embodiments, the mass percentage of the compound represented by Formula I in the bio-based monomer composition is greater than 1% and less than 100%.

[0015] In some embodiments, the mass ratio of the compounds shown in Formula I and Formula II in the bio-based monomer composition does not affect the performance of the subsequent plant oil polyol eugenol ester and bio-based adhesive.

[0016] Furthermore, this invention discloses a method for preparing the above-mentioned bio-based monomer composition, wherein itaconic anhydride and eugenol undergo an esterification reaction under the action of an alkaline catalyst to obtain the bio-based monomer composition.

[0017] .

[0018] In some embodiments, the alkaline catalyst is any one or a combination of several of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate; the molar ratio of itaconic anhydride to eugenol is 1.0:1.0 to 1.5:1.0; the molar ratio of the alkaline catalyst to eugenol is 1.0:1.0 to 1.05:1.0; and the esterification reaction is carried out at 20°C to 40°C.

[0019] In some embodiments, when preparing bio-based monomer compositions using conventional reaction apparatus, the esterification reaction time is 0.5 h to 3 h.

[0020] In some embodiments, when preparing bio-based monomer compositions using conventional reaction apparatus, the esterification reaction time is 0.5 h to 2 h.

[0021] In some embodiments, when preparing bio-based monomer compositions using conventional reaction apparatus, the esterification reaction time is 1 h.

[0022] In some embodiments, the mass percentage of the compound represented by Formula I in the bio-based monomer composition is greater than 1% and less than 100%.

[0023] In some embodiments, the mass ratio of the compounds of Formula I and Formula II in the bio-based monomer composition is controlled by the reaction molar ratio of itaconic anhydride and eugenol, the reaction molar ratio of the alkaline catalyst and eugenol, the esterification reaction temperature, and the esterification reaction time.

[0024] In some embodiments, the alkaline catalyst is sodium hydroxide.

[0025] In some embodiments, the reaction molar ratio of itaconic anhydride and eugenol is 1.0:1.0 to 1.2:1.0.

[0026] In some embodiments, the solvent used in the esterification reaction is any one or a combination of several of water, acetone, tetrahydrofuran, butanone, and ethyl acetate; in conventional reactions, there are no special requirements for the amount of solvent used, as long as the raw materials are dissolved or dispersed evenly.

[0027] In some embodiments, a continuous flow reactor is used to prepare bio-based monomer compositions, and the specific preparation method is as follows:

[0028] Itaconic anhydride is dissolved in a first solvent to obtain a first mixture; eugenol and a basic catalyst are dissolved in a second solvent to obtain a second mixture.

[0029] The first mixture and the second mixture are simultaneously pumped into the first tubular microreactor of the first continuous flow reaction device to carry out esterification reaction, thereby obtaining a bio-based monomer composition.

[0030] In some embodiments, when preparing bio-based eugenol photocurable monomers using a continuous flow reactor, the first solvent is any one or a combination of several of acetone, tetrahydrofuran, butanone, and ethyl acetate; the second solvent is water; the concentration of itaconic anhydride in the first mixture is 1.0 mol / L to 1.5 mol / L; the concentration of eugenol in the second mixture is 1.0 mol / L to 1.5 mol / L; the flow rate of the first mixture pumped into the first tubular microreactor is 1.0 mL / min to 10.0 mL / min; the flow rate of the second mixture pumped into the first tubular microreactor is 1.0 mL / min to 10.0 mL / min; and the reaction residence time in the first tubular microreactor is 5 min to 35 min.

[0031] In some embodiments, when preparing a bio-based monomer composition using a continuous flow reactor, the first solvent is acetone.

[0032] In some embodiments, when preparing the bio-based monomer composition using a continuous flow reactor, the concentration of itaconic anhydride in the first mixture is 1.0 mol / L to 1.2 mol / L.

[0033] In some embodiments, when preparing the bio-based monomer composition using a continuous flow reactor, the concentration of itaconic anhydride in the first mixture is 1.2 mol / L.

[0034] In some embodiments, when preparing the bio-based monomer composition using a continuous flow reactor, the concentration of eugenol in the second mixture is 1.0 mol / L to 1.2 mol / L.

[0035] In some embodiments, when preparing the bio-based monomer composition using a continuous flow reactor, the concentration of eugenol in the second mixture is 1.0 mol / L.

[0036] In some embodiments, when preparing a bio-based monomer composition using a continuous flow reactor, the flow rate of the first mixture pumped into the first tubular microreactor is 2.0 mL / min to 6.0 mL / min.

[0037] In some embodiments, when preparing a bio-based monomer composition using a continuous flow reactor, the first mixture is pumped into the first tubular microreactor at a flow rate of 4.0 mL / min.

[0038] In some embodiments, when preparing a bio-based monomer composition using a continuous flow reactor, the flow rate of the second mixture pumped into the first tubular microreactor is 2.0 mL / min to 6.0 mL / min.

[0039] In some embodiments, when preparing a bio-based monomer composition using a continuous flow reactor, the second mixture is pumped into the first tubular microreactor at a flow rate of 4.0 mL / min.

[0040] In some embodiments, when preparing bio-based monomer compositions using a continuous flow reactor, the reaction residence time in the first tubular microreactor is 15 min to 30 min.

[0041] In some embodiments, when preparing bio-based monomer compositions using a continuous flow reactor, the reaction residence time in the first tubular microreactor is 20 min to 25 min.

[0042] In some embodiments, the first continuous flow reaction apparatus includes a connecting pipe, a first injection pump, a second injection pump, a first micromixer, a first tubular microreactor, and a receiving device; wherein the first injection pump and the second injection pump are connected in parallel to the first micromixer via a connecting pipe; and the first micromixer, the first tubular microreactor, and the receiving device are connected in series via a connecting pipe.

[0043] In some embodiments, the first micro mixer is a T-type micro mixer or a Y-type micro mixer, preferably a Y-type micro mixer.

[0044] In some embodiments, the inner diameter of the first tubular microreactor is 0.05 mm to 5.0 mm.

[0045] In some embodiments, the inner diameter of the first tubular microreactor is 0.1 mm to 2.0 mm.

[0046] In some embodiments, the inner diameter of the first tubular microreactor is 0.5 mm to 1.0 mm.

[0047] In some embodiments, the inner diameter of the first tubular microreactor is 0.5 mm.

[0048] In some embodiments, the interior of the first tubular microreactor may be provided with a temperature control jacket for precise control of the reaction temperature.

[0049] The application of the above-mentioned bio-based monomer composition in the preparation of vegetable oil polyols is also within the scope of protection of this invention.

[0050] In some embodiments, the plant oil polyol includes plant oil polyol eugenol ester.

[0051] Furthermore, the present invention discloses a plant oil polyol eugenol ester, which is prepared by ring-opening of the carboxyl group in the structure of the bio-based monomer composition with the epoxy group in the structure of the epoxidized plant oil.

[0052] In some embodiments, the epoxidized vegetable oil is any one or a combination of several of epoxidized soybean oil, epoxidized cottonseed oil, and epoxidized linseed oil.

[0053] Furthermore, the present invention discloses a method for preparing the above-mentioned plant oil polyol eugenol ester, wherein the bio-based monomer composition undergoes a ring-opening reaction with epoxidized plant oil to obtain the plant oil polyol eugenol ester; a polymerization inhibitor is also added during the ring-opening reaction.

[0054] In some embodiments, the epoxidized vegetable oil is any one or a combination of several of epoxidized soybean oil, epoxidized cottonseed oil, and epoxidized linseed oil; the polymerization inhibitor is p-methoxyphenol or hydroquinone; the molar ratio of the carboxyl group in the bio-based monomer composition to the epoxy group in the epoxidized vegetable oil is controlled to be (0.8~1.2):(0.8~1.2); the amount of the polymerization inhibitor is 0.1%~1.0% of the total mass of the bio-based monomer composition and the epoxidized vegetable oil; the ring-opening reaction is carried out at a reaction temperature of 60℃~120℃.

[0055] In some embodiments, the epoxidized vegetable oil is any one or a combination of two of epoxidized soybean oil and epoxidized linseed oil.

[0056] In some embodiments, the polymerization inhibitor is p-methoxyphenol.

[0057] In some embodiments, the reaction molar ratio of the carboxyl group in the bio-based monomer composition to the epoxy group in the epoxidized vegetable oil is controlled to be 1.0:1.0.

[0058] In some embodiments, the amount of the polymerization inhibitor is 0.1% to 0.5% of the total mass of the bio-based monomer composition and the epoxidized vegetable oil.

[0059] In some embodiments, the amount of the polymerization inhibitor is 0.2% of the total mass of the bio-based monomer composition and the epoxidized vegetable oil.

[0060] In some embodiments, the ring-opening reaction is carried out at a temperature of 80°C to 100°C.

[0061] In some embodiments, the ring-opening reaction is carried out at a temperature of 80°C, 90°C, or 100°C.

[0062] In some embodiments, a catalyst is added during the ring-opening reaction. The catalyst is any one or a combination of tetraethylammonium bromide and triphenylphosphine. The amount of the catalyst is 0.2% to 2.0% of the total mass of the bio-based monomer composition and the epoxidized vegetable oil.

[0063] In some embodiments, a catalyst is added during the ring-opening reaction. The catalyst is any one or a combination of tetraethylammonium bromide and triphenylphosphine. The amount of the catalyst is 0.5% to 2.0% of the total mass of the bio-based monomer composition and the epoxidized vegetable oil.

[0064] In some embodiments, a catalyst is added during the ring-opening reaction. The catalyst is any one or a combination of tetraethylammonium bromide and triphenylphosphine, and the amount of the catalyst is 1.0% of the total mass of the bio-based monomer composition and the epoxidized vegetable oil.

[0065] In some embodiments, eugenol esters of vegetable oil polyols are prepared using a continuous flow reactor. The specific preparation method is as follows:

[0066] The above-mentioned bio-based monomer composition, polymerization inhibitor, and third solvent are mixed to obtain a third mixture; the epoxy vegetable oil and fourth solvent are mixed to obtain a fourth mixture.

[0067] The third and fourth mixtures were simultaneously pumped into the second tubular microreactor of the second continuous flow reactor to carry out ring-opening reactions, thereby producing eugenol ester, a polyol derived from vegetable oil.

[0068] In some embodiments, when preparing eugenol esters of vegetable oil polyols using a continuous flow reactor, the third solvent is any one or a combination of several of acetone, tetrahydrofuran, butanone, and ethyl acetate; the fourth solvent is any one or a combination of several of acetone, tetrahydrofuran, butanone, and ethyl acetate; the concentration of the bio-based monomer composition in the third mixture is 0.1 mol / L to 0.25 mol / L; the concentration of epoxy groups in the epoxidized vegetable oil in the fourth mixture is 0.1 mol / L to 0.25 mol / L; the flow rate of the third mixture pumped into the second tubular microreactor is 1.0 mL / min to 15.0 mL / min; the flow rate of the fourth mixture pumped into the second tubular microreactor is 1.0 mL / min to 15.0 mL / min; and the reaction residence time in the second tubular microreactor is 20 min to 2 h.

[0069] In some embodiments, when preparing eugenol esters of vegetable oil polyols using a continuous flow reactor, the third solvent is acetone.

[0070] In some embodiments, when preparing eugenol esters of vegetable oil polyols using a continuous flow reactor, the fourth solvent is acetone.

[0071] In some embodiments, when preparing eugenol esters of vegetable oil polyols using a continuous flow reactor, the concentration of the bio-based monomer composition in the third mixture is 0.1 mol / L to 0.15 mol / L.

[0072] In some embodiments, when preparing eugenol esters of vegetable oil polyols using a continuous flow reactor, the concentration of the bio-based monomer composition in the third mixture is 0.1 mol / L.

[0073] In some embodiments, when preparing eugenol esters of vegetable oil polyols using a continuous flow reactor, the concentration of epoxy groups in the epoxidized vegetable oil in the fourth mixture is 0.1 mol / L to 0.15 mol / L.

[0074] In some embodiments, when preparing eugenol esters of vegetable oil polyols using a continuous flow reactor, the concentration of epoxy groups in the epoxidized vegetable oil in the fourth mixture is 0.1 mol / L.

[0075] In some embodiments, when preparing eugenol esters of vegetable oil polyols using a continuous flow reactor, the flow rate of the third mixture pumped into the second tubular microreactor is 2.0 mL / min to 5.0 mL / min.

[0076] In some embodiments, when preparing eugenol esters of vegetable oil polyols using a continuous flow reactor, the flow rate of the third mixture pumped into the second tubular microreactor is 3.5 mL / min.

[0077] In some embodiments, when preparing eugenol esters of vegetable oil polyols using a continuous flow reactor, the flow rate of the fourth mixture pumped into the second tubular microreactor is 2.0 mL / min to 5.0 mL / min.

[0078] In some embodiments, when preparing eugenol esters of vegetable oil polyols using a continuous flow reactor, the flow rate of the fourth mixture pumped into the second tubular microreactor is 3.5 mL / min.

[0079] In some embodiments, when preparing eugenol esters of vegetable oil polyols using a continuous flow reactor, the reaction residence time in the second tubular microreactor is 20 min to 1 h.

[0080] In some embodiments, when preparing eugenol esters of vegetable oil polyols using a continuous flow reactor, the reaction residence time in the second tubular microreactor is 20 min, 40 min, or 1 h.

[0081] In some embodiments, the second continuous flow reaction apparatus includes a connecting pipe, a third injection pump, a fourth injection pump, a second micromixer, a second tubular microreactor, and a receiving device; wherein the third injection pump and the fourth injection pump are connected in parallel to the second micromixer via a connecting pipe; the second micromixer, the second tubular microreactor, and the receiving device are connected in series via a connecting pipe.

[0082] In some embodiments, the second micro-mixer is a T-type micro-mixer or a Y-type micro-mixer, preferably a Y-type micro-mixer.

[0083] In some embodiments, the inner diameter of the second tubular microreactor is 0.05 mm to 5.0 mm.

[0084] In some embodiments, the inner diameter of the second tubular microreactor is 0.1 mm to 2.0 mm.

[0085] In some embodiments, the inner diameter of the second tubular microreactor is 0.5 mm to 1.0 mm.

[0086] In some embodiments, the inner diameter of the second tubular microreactor is 0.5 mm.

[0087] In some embodiments, the interior of the second tubular microreactor may be provided with a temperature control jacket for precise control of the reaction temperature.

[0088] In some embodiments, a continuous flow reactor is used to prepare eugenol esters of vegetable oil polyols, and the fourth mixture further includes a catalyst.

[0089] The application of the above-mentioned plant oil polyol eugenol ester or the plant oil polyol eugenol ester prepared by the above-mentioned preparation method in the preparation of adhesives is also within the scope of protection of this invention.

[0090] Furthermore, the present invention discloses a bio-based adhesive comprising the above-mentioned plant oil polyol eugenol ester, reactive diluent, and photoinitiator; wherein the reactive diluent accounts for 10% to 50% of the mass of the adhesive, the photoinitiator accounts for 1% to 5% of the mass of the adhesive, and the remainder is plant oil polyol eugenol ester.

[0091] In some embodiments, the bio-based adhesive comprises the above-mentioned plant oil polyol eugenol ester, reactive diluent, and photoinitiator; the reactive diluent accounts for 10% to 30% of the mass of the adhesive, the photoinitiator accounts for 2% to 5% of the mass of the adhesive, and the remainder is plant oil polyol eugenol ester.

[0092] In some embodiments, the bio-based adhesive comprises the above-mentioned plant oil polyol eugenol ester, reactive diluent, and photoinitiator; the reactive diluent accounts for 20% of the mass of the adhesive, the photoinitiator accounts for 4% of the mass of the adhesive, and the remainder is plant oil polyol eugenol ester.

[0093] In some embodiments, the reactive diluent is any one or a combination of several of the following: trimethylolpropane triacrylate, isobornyl acrylate, phenoxyethyl acrylate, hydroxyethyl acrylate, 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, neopentyl glycol diacrylate, pentaerythritol triacrylate, and pentaerythritol tetraacrylate; and the photoinitiator is any one or a combination of several of the following: 2-hydroxy-2-methylphenylacetone, 1-hydroxy-cyclohexyl-phenyl ketone, and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.

[0094] In some embodiments, the reactive diluent is trimethylolpropane triacrylate.

[0095] In some embodiments, the photoinitiator is 2-hydroxy-2-methylphenylacetone.

[0096] In some embodiments, the bio-based adhesive is applied to a substrate and cured by ultraviolet light irradiation; the wavelength of the ultraviolet light is 365 nm to 405 nm.

[0097] In some embodiments, the bio-based adhesive is applied to a substrate and cured by ultraviolet light; the curing time is 0.5 to 3 hours.

[0098] Beneficial effects:

[0099] (1) The raw materials used in this invention, namely itaconic anhydride, eugenol, and epoxidized vegetable oil, are all derived from renewable biomass resources, reducing dependence on fossil resources. The resulting adhesive is an environmentally friendly product with high bio-based content.

[0100] (2) This invention introduces rigid benzene ring structural units and aliphatic chain structural units into the molecular structure, resulting in adhesives with good mechanical properties and flexibility after curing. The aliphatic chains impart superior flexibility and hydrophobicity to the adhesives. By controlling the presence or absence of a catalyst, adhesive products with different crosslinking densities and properties can be obtained.

[0101] (3) Furthermore, the present invention adopts continuous flow reaction technology, which utilizes its efficient heat and mass transfer characteristics to solve the problem of strong exothermic reaction of carboxyl and epoxy groups in traditional batch process, avoids local overheating and explosive polymerization risk, and the reaction process is mild, safe and controllable.

[0102] (4) Furthermore, the present invention employs continuous flow reaction technology, which is highly efficient and reproducible. Compared with traditional batch reaction which requires several hours or even longer, the present invention significantly shortens the reaction time to the minute level (20~60 min), thus significantly improving production efficiency. At the same time, the continuous flow reaction precisely controls the reaction parameters, ensuring the stability of the structure and the reproducibility of the performance of different batches of products.

[0103] (5) The adhesive provided by the present invention uses a bio-based photocurable monomer with a specific structure to react with epoxy vegetable oil, and with a specific amount of components, it can achieve a good interaction and develop green materials based on renewable biomass resources. Attached Figure Description

[0104] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, and the advantages of the present invention in the above and / or other aspects will become clearer.

[0105] Figure 1This is a schematic diagram of the first continuous flow reaction apparatus used in an embodiment of the present invention.

[0106] Figure 2 This is a schematic diagram of the second continuous flow reaction apparatus used in an embodiment of the present invention.

[0107] Figure 3 This is a typical structural diagram of eugenol ester, a polyol derived from vegetable oil, in an embodiment of the present invention.

[0108] Figure 4 The bio-based eugenol photocurable monomer prepared in Example 1 of this invention 1 H NMR spectrum.

[0109] Figure 5 The infrared spectrum of the plant oil polyol eugenol ester prepared in Example 1 of this invention. Detailed Implementation

[0110] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments, further clarifies the invention. Those skilled in the art should understand that the specific descriptions below are illustrative rather than restrictive, and should not be construed as limiting the scope of protection of the present invention.

[0111] Unless otherwise specified, the experimental methods described in the following embodiments are conventional methods; the reagents and materials described are commercially available unless otherwise specified. The structures, proportions, sizes, etc., illustrated in the accompanying drawings are merely for illustrative purposes and to aid those skilled in the art, and are not intended to limit the implementation of the invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and objectives of the invention, should still fall within the scope of the technical content disclosed in this invention.

[0112] 1. Figure 1 This is a schematic diagram of a first continuous flow reaction apparatus used in an embodiment of the present invention. The first continuous flow reaction apparatus includes a connecting pipe, a first injection pump, a second injection pump, a first micromixer, a first tubular microreactor, and a receiving device; wherein, the first injection pump and the second injection pump are connected in parallel to the first micromixer through the connecting pipe; the first micromixer, the first tubular microreactor, and the receiving device are connected in series through the connecting pipe.

[0113] The first micro-mixer is a Y-type micro-mixer.

[0114] The inner diameter of the first tubular microreactor is 0.5 mm.

[0115] The first tubular microreactor may be equipped with a temperature control jacket inside to precisely control the reaction temperature.

[0116] 2. Figure 2 This is a schematic diagram of the second continuous flow reaction apparatus used in an embodiment of the present invention. The second continuous flow reaction apparatus includes a connecting pipe, a third injection pump, a fourth injection pump, a second micromixer, a second tubular microreactor, and a receiving device; wherein, the third injection pump and the fourth injection pump are connected in parallel to the second micromixer through the connecting pipe; the second micromixer, the second tubular microreactor, and the receiving device are connected in series through the connecting pipe.

[0117] The second micro-mixer is a Y-type micro-mixer.

[0118] The inner diameter of the second tubular microreactor is 0.5 mm.

[0119] The second tubular microreactor may be equipped with a temperature control jacket inside to precisely control the reaction temperature.

[0120] Example 1: Synthesis of bio-based phenolic compound photocurable monomers and preparation of adhesives

[0121] In this embodiment, eugenol is preferably used as a hydroxy compound raw material to carry out continuous flow synthesis of bio-based photocurable monomers, and further prepares plant oil polyol eugenol ester and cured film.

[0122] 1. Continuous flow synthesis of bio-based eugenol photocurable monomers

[0123] First mixture: Itaconic anhydride (13.4 g, 0.12 mol) was dissolved in 100.0 mL of acetone to obtain the first mixture.

[0124] Second mixture: Dissolve sodium hydroxide (4.0 g, 0.1 mol) in 100.0 mL of water to obtain a 1.0 mol / L sodium hydroxide aqueous solution; add eugenol (16.4 g, 0.1 mol) dropwise to the above sodium hydroxide aqueous solution and stir well to obtain the second mixture.

[0125] The molar ratio of itaconic anhydride to eugenol was controlled at 1.2:1 during the esterification reaction. The first mixture and the second mixture were simultaneously pumped into the first tubular microreactor of the first continuous flow reactor at a flow rate of 4.0 mL / min and 4.0 mL / min respectively for the esterification reaction. The inner diameter of the tubular microreactor was 0.5 mm, the retention volume was 200.0 mL, the reaction temperature was 25℃, and the residence time was 25 min, yielding a reaction effluent containing itaconic anhydride-based eugenol monoacid. The reaction effluent underwent acidification, extraction, washing, drying, and rotary evaporation to obtain purified bio-based eugenol photocurable monomer. The separation yield of itaconic anhydride-based eugenol monoacid was 62.3%, and the purity was 91.2%. The acid value was determined by titration with KOH ethanol standard solution, and the acid value was 203.06 mg KOH / g.

[0126] Figure 4 The bio-based eugenol photocurable monomer prepared in Example 1 of this invention 1 H NMR spectrum.

[0127] 2. Continuous flow synthesis of eugenol esters, a polyol from vegetable oils

[0128] (1) The above-obtained bio-based eugenol photocurable monomer is mixed with solvent and polymerization inhibitor to prepare a third mixture, as shown below.

[0129] The bio-based eugenol photocurable monomer (2.76 g, 0.01 mol, acid value 203.06 mgKOH / g) prepared above was dissolved in 100.0 mL of acetone to obtain a eugenol photocurable monomer solution with a concentration of 0.1 mol / L; then, the polymerization inhibitor p-methoxyphenol (0.2% of the total mass of bio-based eugenol photocurable monomer and epoxidized soybean oil) was added to the monomer solution and mixed evenly to obtain a third mixture.

[0130] (2) Fourth mixture: Dissolve 2.54 g of epoxidized soybean oil (0.01 mol of epoxy groups, epoxy value of 6.3%) in 100.0 mL of acetone and mix well to obtain the fourth mixture.

[0131] (3) Purge the entire reaction system with nitrogen to remove all air. Preheat the temperature of the second tubular microreactor of the second continuous flow reaction apparatus to 90°C using a constant temperature circulator. Start the third and fourth metering pumps to simultaneously pump the third mixture at a flow rate of 3.5 mL / min and the fourth mixture at a flow rate of 3.5 mL / min into the static mixer, and then into the second tubular microreactor for the ring-opening reaction. The inner diameter of the pipe is 0.5 mm, the retention volume of the tubular microreactor is 280.0 mL, the reaction temperature is 90°C, and the reaction residence time is 40 min. After the reaction is completed, the reaction effluent enters the collection tank. Distill the collected reaction effluent under reduced pressure at 60°C to recover acetone, obtaining a yellow, transparent, viscous liquid, which is eugenol ester, a polyol derived from vegetable oil.

[0132] Figure 3 This is a typical structural diagram of eugenol ester, a polyol derived from vegetable oil, in an embodiment of the present invention.

[0133] Figure 5 Infrared spectra of eugenol esters, a plant oil polyol prepared from bio-based photocurable eugenol monomers. The figure shows that at 3525 cm⁻¹... -1 The peak at 1737 cm⁻¹ represents the -OH stretching vibration, indicating that epoxidized soybean oil (ESO) underwent an epoxide ring-opening reaction and generated hydroxyl groups. -1 Enhanced ester peak, 1677 cm⁻¹ -1 1638 cm -1 The peaks are C=C stretching vibration peaks. The appearance of these peaks indicates that the bio-based eugenol photocurable monomer has been introduced into the epoxidized soybean oil molecule.

[0134] 3. Preparation of bio-based cured adhesive film

[0135] Add 20 wt% reactive diluent (trimethylolpropane triacrylate) to the eugenol ester of the vegetable oil polyol prepared in step 2 above to obtain an adhesive prepolymer; add 4 wt% photoinitiator (2-hydroxy-2-methylphenylacetone, photoinitiator 1173) to the adhesive prepolymer, and coat it on the surface of the quartz glass substrate to be bonded, with a film thickness of about 100 μm. Photocur it at room temperature by irradiation with an ultraviolet lamp with a wavelength of 365~405 nm, with a curing energy of 1986 mJ / cm² and a curing time of 1 h to obtain a bio-based cured adhesive film.

[0136] Example 2:

[0137] The preparation process is the same as in Example 1, except that in "1. Synthesis of bio-based phenolic compound photocurable monomer", the molar ratio of itaconic anhydride to eugenol is controlled to be 1:1 during the esterification reaction. After the reaction is completed, the reaction effluent is subjected to acidification, extraction, washing, drying, rotary evaporation and other post-treatments to obtain purified bio-based eugenol photocurable monomer. The separation yield of itaconic anhydride-based eugenol monoacid is 56.2%, and the purity is 90.8%.

[0138] Example 3:

[0139] The preparation process is the same as in Example 1, except that in "2. Continuous flow synthesis of vegetable oil polyol eugenol ester", the catalyst triphenylphosphine is used. Triphenylphosphine accounts for 1% of the total mass of bio-based eugenol photocurable monomer and epoxidized soybean oil and is added to the fourth mixture.

[0140] Example 4:

[0141] The preparation process is the same as in Example 3, except that in "2. Continuous flow synthesis of vegetable oil polyol eugenol ester", the catalyst triphenylphosphine is replaced with an equal mass fraction of tetraethylammonium bromide.

[0142] Example 5:

[0143] The preparation process is the same as in Example 1, except that in step 3, "Preparation of Bio-based Cured Adhesive Film", the amount of the reactive diluent trimethylolpropane triacrylate is increased to 40 wt%. The resulting bio-based cured adhesive film is then obtained.

[0144] Example 6:

[0145] The preparation process is the same as in Example 1, except that in "2. Continuous flow synthesis of eugenol esters from vegetable oil polyols", the temperature in the second tubular microreactor is adjusted to 80°C, and the flow rate of the mixture is adjusted (keeping the flow rates of the third and fourth mixtures the same) so that the reaction residence time is 1 h.

[0146] Example 7:

[0147] The preparation process is the same as in Example 1, except that in "2. Continuous flow synthesis of eugenol esters from vegetable oil polyols", the temperature in the second tubular microreactor is adjusted to 100°C, and the flow rate of the mixture is adjusted (keeping the flow rates of the third and fourth mixtures the same) so that the reaction residence time is 20 min.

[0148] Example 8:

[0149] The preparation process is the same as in Example 1, except that in "2. Continuous flow synthesis of vegetable oil polyol eugenol ester", epoxidized soybean oil is replaced with epoxidized linseed oil with the same epoxy value.

[0150] Example 9: Preparation of bio-based phenolic compounds using the traditional batch process

[0151] Following the proportions in Example 1, a 250 mL flask was filled with 100.0 mL of pure water. Sodium hydroxide (4.0 g, 0.1 mol) was dissolved in the water to obtain a 1.0 mol / L sodium hydroxide aqueous solution. Eugenol (16.4 g, 0.1 mol) was added dropwise to the above sodium hydroxide aqueous solution and stirred until homogeneous to obtain a mixture. Itaconic anhydride (13.4 g, 0.12 mol) was added to the mixture in small amounts several times, and an esterification reaction was carried out at 25 °C. After 1 h of reaction, a reaction solution containing bio-based eugenol photocurable monomer was obtained. The reaction solution was post-treated by acidification, extraction, washing, drying, and rotary evaporation to obtain purified bio-based eugenol photocurable monomer. The separation yield of itaconic acid-based eugenol monoacid in the reaction solution was 40.6%, and the purity was 83.6%.

[0152] Example 10: Preparation of vegetable oil polyol eugenol ester and bio-based cured film using traditional batch process

[0153] (1) Continuous flow synthesis of bio-based eugenol photocurable monomer

[0154] The method, material usage, and process parameters are the same as in Example 1.

[0155] (2) Synthesis of eugenol ester, a polyol from vegetable oil

[0156] Following the material dosage and ratio of Example 1, bio-based eugenol photocurable monomer, polymerization inhibitor p-methoxyphenol, and epoxidized soybean oil were added to a 250 mL four-necked flask equipped with a stirrer, thermometer, and reflux condenser, using acetone as the solvent. Under nitrogen protection, stirring was started, and the mixture was heated to 90°C in an oil bath and reacted at this temperature for 12 hours. Temperature changes were monitored during the reaction, and a slight exothermic reaction was observed. After the reaction was completed, the solvent was removed by vacuum distillation to obtain the vegetable oil polyol eugenol ester.

[0157] (3) Preparation of bio-based curable film

[0158] The curing method, material usage, and process parameters are the same as in Example 1.

[0159] Example 11: Performance Testing

[0160] The prepolymers and cured bio-based adhesive films prepared in Examples 1, 3-6, and 10 were subjected to performance tests, and the test methods are as follows:

[0161] (1) Epoxy value: The epoxy value of eugenol ester, a polyol in vegetable oil, was determined by the hydrochloric acid-acetone method in the national standard GB / T 1677-2008.

[0162] (2) Viscosity: The viscosity of the adhesive prepolymer was measured at 25°C using a rotational viscometer.

[0163] (3) Gel content: Weigh the cured bio-based curing film (W1), extract it with acetone for 24 h, take it out and dry it to constant weight (W2), gel content = W2 / W1 × 100%.

[0164] (4) Tensile properties: In accordance with GB / T 1040.3-2006 standard, the bio-based curing film was made into dumbbell-shaped specimens and tested on a universal testing machine.

[0165] (5) Glass transition temperature (Tg): The Tg of the bio-based curing film was determined by differential scanning calorimetry.

[0166] Table 1. Test data of epoxy value and viscosity properties

[0167]

[0168] Table 2. Test data on gel content, tensile properties and glass transition temperature.

[0169]

[0170] The test results show that the continuous flow method of this invention can achieve a higher reaction conversion rate within 40 minutes than the traditional batch reactor method which takes 12 hours, and the product performance is comparable to or better, demonstrating the high efficiency of the continuous flow technology. The cured film prepared under catalytic conditions exhibits poorer performance, possibly due to other side reactions caused by the catalyst.

[0171] This invention provides a concept and method for the preparation and application of bio-based monomers. Many methods and approaches exist for implementing this technical solution; the above description is merely a preferred embodiment of the invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications should also be considered within the scope of protection of this invention. All components not explicitly stated in this embodiment can be implemented using existing technologies.

Claims

1. A bio-based monomer composition, characterized in that, The bio-based monomer composition is a mixture of compounds shown in Formula I and Formula II: 。 2. The method for preparing the bio-based monomer composition according to claim 1, characterized in that, Itaconic anhydride and eugenol undergo an esterification reaction under the action of an alkaline catalyst to obtain a bio-based monomer composition. 。 3. The preparation method according to claim 2, characterized in that, The alkaline catalyst is any one or a combination of several of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate; the molar ratio of itaconic anhydride to eugenol is 1.0:1.0 to 1.5:1.0; the molar ratio of the alkaline catalyst to eugenol is 1.0:1.0 to 1.05:1.0; the esterification reaction is carried out at 20℃ to 40℃.

4. The preparation method according to claim 2, characterized in that, Bio-based monomer compositions were prepared using a continuous flow reactor. The specific preparation method is as follows: Itaconic anhydride is dissolved in a first solvent to obtain a first mixture; eugenol and a basic catalyst are dissolved in a second solvent to obtain a second mixture. The first mixture and the second mixture are simultaneously pumped into the first tubular microreactor of the first continuous flow reaction device to carry out esterification reaction, thereby obtaining a bio-based monomer composition.

5. The preparation method according to claim 4, characterized in that, The first solvent is any one or a combination of several of acetone, tetrahydrofuran, butanone, and ethyl acetate; the second solvent is water; the concentration of itaconic anhydride in the first mixture is 1.0 mol / L to 1.5 mol / L; the concentration of eugenol in the second mixture is 1.0 mol / L to 1.5 mol / L; the flow rate of the first mixture into the first tubular microreactor is 1.0 mL / min to 10.0 mL / min; the flow rate of the second mixture into the first tubular microreactor is 1.0 mL / min to 10.0 mL / min; the reaction residence time in the first tubular microreactor is 5 min to 35 min.

6. The use of the bio-based monomer composition according to claim 1 in the preparation of vegetable oil polyols.

7. The application according to claim 6, characterized in that, The plant oil polyols mentioned include eugenol esters.

8. A plant oil polyol eugenol ester, characterized in that, The plant oil polyol eugenol ester is prepared by ring-opening the epoxide group in the structure of the epoxidized plant oil by the carboxyl group in the structure of the bio-based monomer composition of claim 1.

9. The method for preparing eugenol ester, a polyol from vegetable oil, according to claim 8, is characterized in that... The bio-based monomer composition of claim 1 is subjected to a ring-opening reaction with epoxidized vegetable oil to obtain eugenol ester, a vegetable oil polyol; a polymerization inhibitor is also added during the ring-opening reaction.

10. The preparation method according to claim 9, characterized in that, The epoxidized vegetable oil is any one or a combination of several of epoxidized soybean oil, epoxidized cottonseed oil, and epoxidized linseed oil; the polymerization inhibitor is p-methoxyphenol or hydroquinone; the molar ratio of the carboxyl group in the bio-based monomer composition to the epoxy group in the epoxidized vegetable oil is controlled to be (0.8~1.2):(0.8~1.2); the amount of the polymerization inhibitor is 0.1%~1.0% of the total mass of the bio-based monomer composition and the epoxidized vegetable oil; the ring-opening reaction is carried out at a reaction temperature of 60℃~120℃.

11. The preparation method according to claim 9, characterized in that, A catalyst is also added during the ring-opening reaction process. The catalyst is any one or a combination of tetraethylammonium bromide and triphenylphosphine. The amount of the catalyst is 0.2% to 2.0% of the total mass of the bio-based monomer composition and the epoxidized vegetable oil.

12. The preparation method according to claim 9, characterized in that, Eugenol esters, a polyol derived from vegetable oils, were prepared using a continuous flow reactor. The specific preparation method is as follows: The bio-based monomer composition of claim 1 is mixed with a polymerization inhibitor and a third solvent to obtain a third mixture; the epoxy vegetable oil is mixed with a fourth solvent to obtain a fourth mixture. The third and fourth mixtures were simultaneously pumped into the second tubular microreactor of the second continuous flow reactor to carry out ring-opening reactions, thereby producing eugenol ester, a polyol derived from vegetable oil.

13. The preparation method according to claim 12, characterized in that, The third solvent is any one or a combination of several of acetone, tetrahydrofuran, butanone, and ethyl acetate; the fourth solvent is any one or a combination of several of acetone, tetrahydrofuran, butanone, and ethyl acetate; the concentration of the bio-based monomer composition in the third mixture is 0.1 mol / L to 0.25 mol / L; the concentration of epoxy groups in the epoxidized vegetable oil in the fourth mixture is 0.1 mol / L to 0.25 mol / L; the flow rate of the third mixture pumped into the second tubular microreactor is 1.0 mL / min to 15.0 mL / min; the flow rate of the fourth mixture pumped into the second tubular microreactor is 1.0 mL / min to 15.0 mL / min; the reaction residence time in the second tubular microreactor is 20 min to 2 h.

14. The preparation method according to claim 12, characterized in that, The fourth mixture also includes a catalyst.

15. The use of the eugenol ester of vegetable oil polyol according to claim 8 or the eugenol ester of vegetable oil polyol prepared by any one of claims 9 to 14 in the preparation of adhesives.

16. A bio-based adhesive, characterized in that, The bio-based adhesive comprises the plant oil polyol eugenol ester as described in claim 8, an active diluent, and a photoinitiator; The reactive diluent accounts for 10% to 50% of the adhesive by mass, the photoinitiator accounts for 1% to 5% of the adhesive by mass, and the balance is eugenol ester, a plant oil polyol.

17. The bio-based adhesive according to claim 16, characterized in that, The reactive diluent is any one or a combination of several of the following: trimethylolpropane triacrylate, isobornyl acrylate, phenoxyethyl acrylate, hydroxyethyl acrylate, 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, neopentyl glycol diacrylate, pentaerythritol triacrylate, and pentaerythritol tetraacrylate; the photoinitiator is any one or a combination of several of the following: 2-hydroxy-2-methylphenylpropanone, 1-hydroxy-cyclohexyl-phenyl ketone, and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.

18. The bio-based adhesive according to claim 16, characterized in that, In use, the bio-based adhesive is applied to a substrate and cured by ultraviolet light irradiation; the wavelength of the ultraviolet light is 365 nm to 405 nm.

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