High-functionality plant phenol-based polyether polyol, preparation method thereof and polyurethane adhesive

Abstract

The invention relates to the technical field of polyols, and particularly discloses a high-functionality plant phenol-based polyether polyol, a preparation method thereof and a polyurethane adhesive. The invention relates to high-functionality plant phenol-based polyether polyol, which is prepared from the following raw materials: plant phenol glycidyl ether and a dihydroxy compound in a molar ratio of 1: (1.8-2.2), the preparation method comprises the following steps: obtaining a polyol intermediate from plant phenol glycidyl ether and a dihydroxy compound under the action of a first catalyst, and then obtaining a product under the action of a second catalyst. The high-functionality plant phenol-based polyether polyol provided by the invention has a plurality of hydroxyl groups with high reaction activity, so that the hydroxyl content and the reaction activity of a plant phenol-based high polymer material are remarkably improved, and the application range is widened.

Description

Technical Field

[0001] The present application relates to the technical field of polyols, and more specifically, to a high-functionality plant phenol-based polyether polyol, a preparation method thereof, and a polyurethane adhesive. Background Art

[0002] Cashew nut shell liquid is a raw material extracted from the soft honeycomb structure of cashew nut shells, and cardol is a compound containing two hydroxyl functional groups obtained by refining and purifying cashew nut shell liquid. It is a natural, green, environmentally friendly renewable resource. Cardol is based on a benzene ring, on which there are three reaction sites, namely, phenolic hydroxyl group, 0-3 unsaturated bonds on the C15 long side chain at the meta-position of the phenolic hydroxyl group, and active hydrogen on the benzene ring. The unique chemical structure makes cardol have both the rigidity of the benzene ring and the flexibility brought by the long carbon chain; it has both the characteristics of aromatic compounds and the characteristics of aliphatic hydrocarbons.

[0003] The preparation of cardol-based polyether polyols using cardol and polyols as raw materials increases the number of functional groups in plant phenol molecules, effectively improves the bioavailability of plant phenols, and provides more possibilities for further chemical modification and functionalization. This makes plant phenol-based polyether polyols have more potential for the development of new bio-based materials and has broad application prospects in the fields of surfactants, cross-linking modifiers, and other polymer material technologies.

[0004] In view of the above-mentioned related technologies, the inventors found that the current polyether polyol materials containing plant phenols are mainly monohydroxyl polyoxyethylene ethers and polyoxypropylene ethers, which are prepared by adding ethylene oxide or propylene oxide to the active groups of plant phenols. Such polyether polyols have a small number of hydroxyl groups and generally can only exist as end caps or side chains in the polymer structure, which seriously limits the application of plant phenol-based polyether polyols. Summary of the invention

[0005] In order to increase the active hydroxyl content of plant phenol-based polyether polyol, the present application provides a high-functionality plant phenol-based polyether polyol and a preparation method thereof.

[0006] In the first aspect, the present application provides a high-functionality plant phenol-based polyether polyol, which adopts the following technical scheme: a high-functionality plant phenol-based polyether polyol, the raw materials include plant phenol glycidyl ether and dihydroxy compound in a molar ratio of 1: (1.8-2.2); the structural formula of the plant phenol glycidyl ether is Wherein n is 0, 2, 4 or 6; the structure of the high-functionality plant phenolic polyether polyol is as follows: Wherein R is the characteristic segment of the dihydroxy compound.

[0007] By adopting the above technical scheme, plant phenol-based polyether polyols are prepared using plant phenol glycidyl ethers of specific structural formulas and dihydroxy compounds as raw materials within a specified molar ratio range, and the functionality and molecular weight distribution of the product can be effectively controlled, so that the product has a higher functionality.

[0008] The product retains the long alkyl side chain and double bond in plant phenol, introduces rigid benzene rings and flexible polyether long chains, and significantly improves the bonding strength, mechanical properties and aging resistance of plant phenol-based polyether polyols during application. At the same time, the resulting product has 4 or more highly reactive hydroxyl groups, which significantly improves the hydroxyl content and reactivity of polyether polymer materials, providing more possibilities for further chemical modification and functionalization.

[0009] Optionally, the dihydroxy compound is a linear or branched dihydroxy structure selected from any one or more combinations of bisphenol A, bisphenol S, polypropylene glycol or polyethylene glycol.

[0010] By adopting the above technical scheme, the use of a straight-chain or branched dihydroxy structure can make the position of the hydroxyl group of the obtained plant phenol-based polyether polyol relatively open, with less steric hindrance, the hydroxyl group is more exposed, and the reaction activity of the hydroxyl group is correspondingly improved, making the plant phenol-based polyether polyol easier to react with other functional groups.

[0011] In addition, the introduction of straight-chain or branched molecular structures makes the molecular chains of the products more flexible. This flexibility helps the molecular chains to better adjust their conformations during the reaction, making it easier for hydroxyl groups to approach and react with other functional groups.

[0012] Optionally, the dihydroxy compound is selected from any one or a combination of polypropylene glycol or polyethylene glycol.

[0013] By adopting the above technical solution, polypropylene glycol and polyethylene glycol are linear or slightly branched polymers, and their molecular structures contain multiple repeated ether bonds and terminal hydroxyl groups, which can significantly improve the functionality of the product.

[0014] In contrast, the molecular structures of bisphenol A and bisphenol S are relatively complex, and the hydroxyl groups may be hindered by adjacent benzene rings or groups, resulting in reduced reactivity. The availability of hydroxyl groups is lower than that of polypropylene / ethylene glycol, making it relatively difficult to react with plant phenol glycidyl ether. In the structures of polypropylene glycol and polyethylene glycol, hydroxyl groups can more easily attack the epoxy groups of glycidyl ethers, open the epoxy ring, form stable intermediates, and then undergo subsequent reactions. In addition, the plant phenol-based polyether polyols generated with the participation of polypropylene glycol and polyethylene glycol are more active and can improve the performance of polyurethanes more.

[0015] In a second aspect, the present application provides a method for preparing a high-functionality plant phenol-based polyether polyol, using the following technical solution: A method for preparing a high-functionality plant phenolic polyether polyol comprises the following steps: The dihydroxy compound and the first catalyst are mixed according to a ratio, and after heating to 85-100° C., the plant phenol glycidyl ether is slowly added, and then the temperature is kept at 85-100° C. for 2-6 hours to obtain a polyol intermediate; A second catalyst is added to the polyol intermediate, and the temperature is raised to 80-90° C. in a nitrogen atmosphere. Then ethylene oxide is added, and a polymerization reaction is carried out at 130-150° C., and then the mixture is cooled to room temperature to obtain the polyol intermediate.

[0016] By setting up the above process and controlling the ratio of dihydroxy compounds and plant phenol glycidyl ether, the functionality and molecular weight distribution of the product can be further effectively controlled, so that the product has a higher functionality. Plant phenols are derived from natural plants, are renewable and have good biodegradability, which means that they can be decomposed by microorganisms in the natural environment after use and will not cause long-term pollution to the environment.

[0017] Compared with traditional petroleum-based polyols as raw materials, the present application meets the requirements of environmental protection and sustainable development, and helps to reduce carbon emissions and environmental pollution. In addition, the preparation method of the present application is relatively mild and suitable for large-scale industrial production.

[0018] Optionally, the added amount of the first catalyst is 0.1-1% of the total mass of the dihydroxy compound and the plant phenol glycidyl ether; the added amount of the second catalyst is 0.1-1% of the mass of the intermediate; and the added amount of the ethylene oxide is 1-10% of the mass of the intermediate.

[0019] Optionally, the first catalyst is selected from any one or more of benzyltrimethylammonium bromide, benzyltriethylammonium bromide, benzyltributylammonium bromide, tetramethylammonium bromide, tetraethylammonium bromide, tetrapropylammonium bromide, tetrabutylammonium bromide, hexadecyltrimethylammonium bromide, boron trifluoride etherate, triphenylphosphine, sodium hydroxide or potassium hydroxide.

[0020] Optionally, the second catalyst is selected from any one or more of an alkali metal catalyst, a double metal cyanide catalyst, and an alkyl aluminum phosphate catalyst.

[0021] By adopting the above technical scheme, using the first / second catalyst of the present application and preparing according to the corresponding amount of auxiliary agent, the ring-opening polymerization reaction and the polymerization reaction of ethylene oxide can be effectively promoted, which helps to control the functionality and molecular weight distribution of the product.

[0022] Optionally, a high-functionality plant phenol-based polyether polyol of the present application is used in the preparation of surfactants, adhesives, environmentally friendly coatings, cross-linking modifiers, packaging materials and the synthesis of polyurethanes.

[0023] In a third aspect, the present application provides a polyurethane adhesive prepared using the high-functionality plant phenol-based polyether polyol of the present application.

[0024] Optionally, the mass proportion of high-functionality plant phenol-based polyether polyol in the polyurethane adhesive is 1-3.5%.

[0025] By adopting the above technical scheme, the high-functionality plant phenol-based polyether polyol of the present application has a large number of hydroxyl groups in different side chains, which is more conducive to polycondensation and cross-linking, forming more adhesive points. When 1-3.5% of the high-functionality plant phenol-based polyether polyol of the present application is added to the polyurethane adhesive, the rate of increase of the viscosity of the system is significantly improved, indicating that the hydroxyl group activity in the high-functionality plant phenol-based polyether polyol is relatively high and can be quickly cross-linked in the system. In a two-component polyurethane adhesive, the bonding strength of the adhesive can be significantly improved and the toughness can be increased.

[0026] In summary, this application has the following beneficial effects: 1. Since the present application uses plant phenol glycidyl ether and dihydroxy compounds of specific structures as raw materials to prepare plant phenol-based polyether polyols, the product retains the long alkyl side chains and double bonds in plant phenols, introduces rigid benzene rings and flexible polyether long chains, and has 4 or more highly reactive hydroxyl groups, which significantly improves the functionality of the product, provides more possibilities for further chemical modification and functionalization, and effectively broadens the application scope of plant phenol-based polyether polymer materials.

[0027] 2. In the present application, a straight-chain or branched dihydroxy structure is preferably used, which can make the position of the hydroxyl group of the obtained plant phenolic polyether polyol relatively open, with less steric hindrance, and the hydroxyl group is more exposed, further improving the hydroxyl reaction activity of the product plant phenolic polyether polyol.

[0028] 3. The preparation method of the present application is relatively mild, can effectively promote the ring-opening polymerization reaction and the polymerization reaction of ethylene oxide, helps to control the functionality and molecular weight distribution of the product, and is suitable for large-scale industrial production.

[0029] 4. A high-functionality plant phenol polyether polyol of the present application is used to prepare a polyurethane adhesive, which can quickly cross-link in the system, significantly increase the viscosity increase rate of the system, enhance the bonding strength of the adhesive, and increase the toughness of the adhesive. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The deuterated chloroform phase after derivatization of the product obtained in Example 61 H-NMR spectrum.

[0031] Figure 2 This is a test of the viscosity increase rate of the polyurethane adhesive system obtained in Application Example 1 and Comparative Example 1. DETAILED DESCRIPTION

[0032] The following examples further illustrate the present application in detail.

[0033] raw material Unless otherwise specified, the raw materials used in the examples and comparative examples of this application are all commercially available products, specifically: Bisphenol A, selected from Shanghai Yuanye Biotechnology Co., Ltd., T90137; Bisphenol S, selected from Shanghai Yuanye Biotechnology Co., Ltd., B27890; Polypropylene glycol, HO(C3H6O)nH, average molecular weight 2000; Polyethylene glycol, HO(CH2CH2O)nH, average molecular weight 2000; Boron trifluoride ethyl ether, selected from Hansi Chemical, B802217; Sodium hydride, selected from Jinan Huifengda Chemical, HFD-698; Ethylene oxide, selected from Jieshikai, KA776847; Toluene diisocyanate, selected from Shanghai Yuanye Biotechnology Co., Ltd., W10121; Poly(hexanediol adipate), selected from Jiangsu Congzhong Chemical Industry, 13832; Dibutyltin dilaurate, selected from Shanghai Yuanye Biotechnology Co., Ltd., W10608. Example

[0034] Example 1 A high-functionality plant phenol-based polyether polyol, the raw materials include plant phenol glycidyl ether and a dihydroxy compound in a molar ratio of 1:2, wherein the structural formula of the plant phenol glycidyl ether is The dihydroxy compound is bisphenol A; the first catalyst is boron trifluoride etherate; the second catalyst is an alkali metal catalyst sodium hydride; The preparation method of the above-mentioned high-functionality plant phenol-based polyether polyol comprises the following steps: S1: mixing the dihydroxy compound and the first catalyst according to a ratio to obtain a blend; S2: Add the blend into a four-necked flask, stir and mix evenly, introduce nitrogen to replace the air, heat to 85° C. under a nitrogen atmosphere, slowly add 43.5 g of plant phenol glycidyl ether, the amount of the first catalyst added is 0.3% of the total mass of the dihydroxy compound and the plant phenol glycidyl ether, and keep warm at 90° C. for 4 h to obtain a polyol intermediate; S3: Add the above polyol intermediate into a high-pressure reactor, then add the second catalyst, the amount of the second catalyst added is 0.8% of the mass of the intermediate, introduce nitrogen to replace the air, and under the protective atmosphere of nitrogen, heat to 90° C. and then add ethylene oxide, the amount of ethylene oxide added is 4% of the mass of the intermediate, control the temperature at 150° C. to carry out polymerization reaction, and cool to room temperature after the reaction is completed to obtain a high-functionality plant phenol-based polyether polyol, whose structure is as follows: Wherein n is 0, and R is the characteristic chain segment of bisphenol A.

[0035] Example 2 A high-functionality plant phenol-based polyether polyol, which is different from Example 1 in that the raw materials include plant phenol glycidyl ether and dihydroxy compound in a molar ratio of 1:1.8, wherein the structural formula of the plant phenol glycidyl ether is The preparation method of the above-mentioned high-functionality plant phenol-based polyether polyol comprises the following steps: S1: mixing the dihydroxy compound and the first catalyst according to a ratio to obtain a blend; S2: adding the blend into a four-necked flask, stirring and mixing evenly, introducing nitrogen to replace the air, heating to 85° C. under a nitrogen atmosphere, and then slowly adding 43.5 g of plant phenol glycidyl ether, wherein the amount of the first catalyst added is 1% of the total mass of the dihydroxy compound and the plant phenol glycidyl ether, and the mixture is kept at 85° C. for 6 h to obtain a polyol intermediate; S3: Add the polyol intermediate into a high-pressure reactor, then add the second catalyst, the amount of the second catalyst added is 1% of the mass of the intermediate, introduce nitrogen to replace the air, and under the protective atmosphere of nitrogen, heat to 80° C. and then add ethylene oxide, the amount of ethylene oxide added is 10% of the mass of the intermediate, control the temperature at 130° C. to carry out polymerization reaction, and cool to room temperature after the reaction is completed to obtain a high-functionality plant phenol-based polyether polyol, whose structure is as follows: Where n is 2, and R is the characteristic chain segment of bisphenol A.

[0036] Example 3 A high-functionality plant phenol-based polyether polyol, which is different from Example 1 in that the raw materials include plant phenol glycidyl ether and dihydroxy compound in a molar ratio of 1:2.1, wherein the structural formula of the plant phenol glycidyl ether is The preparation method of the above-mentioned high-functionality plant phenol-based polyether polyol comprises the following steps: S1: mixing the dihydroxy compound and the first catalyst according to a ratio to obtain a blend; S2: Add the blend into a four-necked flask, stir and mix evenly, introduce nitrogen to replace the air, heat to 90° C. under a nitrogen atmosphere, slowly add 43.5 g of plant phenol glycidyl ether, the amount of the first catalyst added is 0.5% of the total mass of the dihydroxy compound and the plant phenol glycidyl ether, and keep warm at 100° C. for 2 h to obtain a polyol intermediate; S3: Add the polyol intermediate into a high-pressure reactor, then add the second catalyst, the amount of the second catalyst added is 0.1% of the mass of the intermediate, introduce nitrogen to replace the air, and under the protective atmosphere of nitrogen, heat to 90° C. and then add ethylene oxide, the amount of ethylene oxide added is 1% of the mass of the intermediate, control the temperature at 140° C. to carry out polymerization reaction, and cool to room temperature after the reaction is completed to obtain a high-functionality plant phenol-based polyether polyol, the structure of which is as follows: Where n is 4, and R is the characteristic chain segment of bisphenol A.

[0037] Example 4 A high-functionality plant phenol-based polyether polyol, which is different from Example 1 in that the raw materials include plant phenol glycidyl ether and dihydroxy compound in a molar ratio of 1:2.2, wherein the structural formula of the plant phenol glycidyl ether is The dihydroxy compound is bisphenol A; the first catalyst is boron trifluoride etherate; The preparation method of the above-mentioned high-functionality plant phenol-based polyether polyol comprises the following steps: S1: mixing the dihydroxy compound and the first catalyst according to a ratio to obtain a blend; S2: Add the blend into a four-necked flask, stir and mix evenly, introduce nitrogen to replace the air, heat to 100° C. under a nitrogen atmosphere, slowly add 43.5 g of plant phenol glycidyl ether, the amount of the first catalyst added is 0.1% of the total mass of the dihydroxy compound and the plant phenol glycidyl ether, and keep warm at 100° C. for 4 h to obtain a polyol intermediate; S3: Add the polyol intermediate into a high-pressure reactor, then add the second catalyst, the amount of the second catalyst added is 0.4% of the mass of the intermediate, introduce nitrogen to replace the air, and under the protective atmosphere of nitrogen, heat to 80° C. and then add ethylene oxide, the amount of ethylene oxide added is 3% of the mass of the intermediate, control the temperature at 150° C. to carry out polymerization reaction, and cool to room temperature after the reaction is completed to obtain a high-functionality plant phenol-based polyether polyol, the structure of which is as follows: Where n is 6, and R is the characteristic chain segment of bisphenol A.

[0038] Example 5 A high-functionality plant phenol-based polyether polyol is different from Example 1 in that the dihydroxy compound in the raw material is bisphenol S, and the other steps are the same as those in Example 1. The structure of the product high-functionality plant phenol-based polyether polyol is as follows: Wherein n is 0, and R is the characteristic chain segment of bisphenol S.

[0039] Example 6 A high-functionality plant phenolic polyether polyol is different from Example 1 in that the dihydroxy compound in the raw material is polypropylene glycol, and the other steps are the same as those in Example 1. The structure of the product high-functionality plant phenolic polyether polyol is as follows: Wherein n is 0, and R is a characteristic chain segment of polypropylene glycol.

[0040] Example 7 A high-functionality plant phenolic polyether polyol is different from Example 1 in that the dihydroxy compound in the raw material is polyethylene glycol, and the other steps are the same as those in Example 1. The structure of the product high-functionality plant phenolic polyether polyol is as follows: Wherein n is 0, and R is a characteristic chain segment of polyethylene glycol.

[0041] Example 8 A high-functionality plant phenolic polyether polyol is different from Example 1 in that the dihydroxy compound in the raw material is polyethylene glycol and polypropylene glycol mixed in a molar ratio of 1:2, and the other steps are the same as Example 1. The structure of the product high-functionality plant phenolic polyether polyol is as follows: Wherein n is 0, and R is a combined characteristic chain segment of polypropylene glycol and polyethylene glycol.

[0042] Application Examples Application Example 1 A polyurethane adhesive, wherein the raw materials and amounts thereof are shown in Table 1, wherein the high-functionality plant phenol-based polyether polyol is the high-functionality plant phenol-based polyether polyol obtained in Example 1; the polyisocyanate is toluene diisocyanate; Table 1 The preparation method of the polyurethane adhesive comprises the following steps: S1: mixing high-functionality plant phenolic polyether polyol, poly(hexanediol adipate), polyisocyanate and calcium carbonate, heating to 80° C. under a nitrogen atmosphere for reaction for 2.5 h, and vacuum degassing for 0.5 h to obtain component A; S2: Pour the high-functionality plant phenolic polyether polyol into a beaker, add 1,4-butanediol, dibutyltin dilaurate and calcium carbonate, raise the temperature to 80° C. and stir for 1.5 h under a nitrogen atmosphere to obtain component B; S3: Mix component B and component A, stir evenly and pour into the mold, evacuate at 80℃ until the bubbles disappear or become very small, and cure at constant temperature.

[0043] Application Example 2-4 A polyurethane adhesive, which is different from Application Example 1 in that the raw materials and amounts are as shown in Table 1, and the other steps are the same as those of Application Example 1.

[0044] Application Example 5-11 A polyurethane adhesive, which is different from Application Example 1 in that the source of the high-functionality plant phenol-based polyether polyol in the raw material is shown in Table 2, and the other steps are the same as those in Application Example 1.

[0045] Table 2 Comparative Example Comparative Example 1 A polyurethane adhesive is disclosed, which differs from Application Example 1 in that the high-functionality plant phenol-based polyether polyol in the raw material is replaced by poly(hexanediol adipate) of an equal mass, and the other steps are the same as those of Application Example 1.

[0046] Performance testing Test Example 1 High-functionality plant phenolic polyether polyol The high-functionality plant phenolic polyether polyol obtained in Examples 1-8 was subjected to performance test tests on appearance, viscosity and hydroxyl content. Each test was performed 3 times, and the average value was taken as the final result, and the final result was recorded in Table 3.

[0047] 1. Viscosity: Refer to the relevant provisions of GB / T 12008.7-2010 "Plastic polyether polyols Part 7: Determination of viscosity" for viscosity test.

[0048] 2. Volatility: Refer to the relevant provisions of GB / T 2793 "Determination of non-volatile content of adhesives" to test the non-volatile content.

[0049] 3. Hydroxyl value content: refer to the relevant provisions of GB / T 12008.3-2009 "Plastic polyether polyols Part 3: Determination of hydroxyl value", and test the hydroxyl content by phthalic anhydride method.

[0050] Table 3 It can be seen from the performance test results in Table 3 that the high-functionality plant phenol-based polyether polyol of the present application is a yellow transparent liquid with uniform color and physical state.

[0051] The viscosity of a high-functionality plant phenolic polyether polyol of the present application is in the range of 1000-2500 mpa.s / 25°C, the non-volatile content is ≥99.7%, and the hydroxyl value content is in the range of 50-220 mgKOH / g. This indicates that the high-functionality plant phenolic polyether polyol of the present application has a large number of highly reactive hydroxyl groups, a high purity, and can give the product better reactivity and a higher crosslinking density, and a higher viscosity value.

[0052] When polyethylene glycol and polypropylene glycol are used as dihydroxy compounds to prepare plant phenol-based polyether polyols, the hydroxyl groups in the product are more easily exposed, which gives the plant phenol-based polyether polyols higher hydroxyl reactivity, which significantly increases their viscosity value.

[0053] Test Example 2 High-functionality plant phenolic polyether polyol structure test The structure of the product obtained in Example 6 was tested by hydrogen nuclear magnetic resonance spectroscopy.

[0054] Figure 1 The deuterated chloroform phase of the obtained product 1 H-NMR spectrum, in which the chemical shift of the methylene group connected to the primary hydroxyl group is at 4.29 ppm.

[0055] The hydroxyl value and 1 The H-NMR spectrum shows that the main high-functionality plant phenolic polyether polyols are of the following structure: Wherein R is the characteristic chain segment of polypropylene glycol, which is consistent with the theoretical structure.

[0056] Test Example 3: Mechanical properties test of polyurethane adhesive The following relevant performance test was carried out on a polyurethane adhesive obtained from Example 1-11 and Comparative Example 1. Each group of tests was carried out 3 times, and the average value was taken as the final result, and the final result was recorded in Table 4.

[0057] 1. Shear strength test: According to GB / T 7124-2008 standard, after mixing components A and B evenly, 3003 aluminum materials without primer coating and surface treatment are bonded to 3003 aluminum materials to prepare shear test pieces. The shear test pieces are cured for 7 days at a temperature of (23±2)℃ and a relative humidity of (50±5)%RH. The thickness of the adhesive layer is 0.5mm, and the shear strength is tested.

[0058] 2. Tensile strength and elongation at break test: Mix components A and B evenly and press them into a sheet with a thickness of about 2 mm. Curing for 7 days at a temperature of (23±2)°C and a relative humidity of (50±5)%RH is carried out according to the standard test, using a type 1 tool and testing according to GB / T 528.

[0059] 3. Peel strength: After components A and B are uniformly mixed to form a polyurethane adhesive, the peel strength test method for adhesives (flexible material to flexible material) in GB-T 2791-1995 is used to measure the peel strength using a universal testing machine.

[0060] Table 4 According to the performance test results in Table 4, it can be seen that the high-functionality plant phenolic polyether polyol of the present application can be used to prepare a two-component polyurethane adhesive. The polyurethane adhesive prepared from the high-functionality plant phenolic polyether polyol of the present application as a raw material can significantly improve the mechanical properties of the polyurethane adhesive.

[0061] When polypropylene glycol and polyethylene glycol are used as dihydroxy compounds, they show better mechanical properties when used in the preparation of polyurethane adhesives than when bisphenol A and bisphenol S are used as dihydroxy compounds to prepare high-functionality plant phenolic polyether polyols. When polypropylene glycol and polyethylene glycol are selected as dihydroxy compounds, the polyurethane adhesive is endowed with better mechanical properties and peeling force. This may be due to the better reactivity of the mixed dihydroxy compounds in the ring-opening reaction, and on the other hand, the side chain of polypropylene can maintain a stable network structure to a certain extent in the polyurethane adhesive system, obtaining more stable cross-linking points, while the linear structure of polyethylene glycol is conducive to improving toughness and supplementing adhesive points. By controlling the mixing of polyethylene glycol and polypropylene glycol in a molar ratio of 1:2, the mechanical properties are optimized.

[0062] Test Example 4: Testing of the viscosity-increasing performance of polyurethane adhesive The increasing speed of the viscosity of the polyurethane adhesive obtained in Example 1 and Comparative Example 1 was tested respectively, and the viscosity values ​​of the system were tested at different times and plotted.

[0063] like Figure 2 As shown, 1% of the high-functionality plant phenolic polyether polyol of the present application is used in the preparation of polyurethane adhesives, which can quickly increase the viscosity of the system. This also shows that the hydroxyl groups in the high-functionality plant phenolic polyether polyol of the present application have higher activity, can be quickly cross-linked, and can quickly improve the bonding force in a two-component polyurethane adhesive and increase the toughness of the polyurethane adhesive.

[0064] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A high-functionality plant phenolic polyether polyol, characterized in that: The raw materials include plant phenol glycidyl ether and dihydroxy compound in a molar ratio of 1:(1.8-2.2); the structural formula of the plant phenol glycidyl ether is Wherein n is 0, 2, 4 or 6; the structure of the high-functionality plant phenolic polyether polyol is as follows: Wherein R is the characteristic segment of the dihydroxy compound.

2. The high-functionality plant phenolic polyether polyol according to claim 1, characterized in that: The dihydroxy compound is a linear or branched dihydroxy structure, and is selected from any one or more combinations of bisphenol A, bisphenol S, polypropylene glycol or polyethylene glycol.

3. The high-functionality plant phenolic polyether polyol according to claim 2, characterized in that: The dihydroxy compound is selected from any one of polypropylene glycol and polyethylene glycol or a combination of both.

4. A method for preparing a high-functionality plant phenolic polyether polyol according to any one of claims 1 to 3, characterized in that: The following steps are involved: The dihydroxy compound and the first catalyst are mixed according to a ratio, and after heating to 85-100° C., the plant phenol glycidyl ether is slowly added, and then the temperature is kept at 85-100° C. for 2-6 hours to obtain a polyol intermediate; A second catalyst is added to the polyol intermediate, and the temperature is raised to 80-90° C. in a nitrogen atmosphere. Then ethylene oxide is added, and a polymerization reaction is carried out at 130-150° C., and then the mixture is cooled to room temperature to obtain the polyol intermediate.

5. The method for preparing the high-functionality plant phenolic polyether polyol according to claim 4, characterized in that: The addition amount of the first catalyst is 0.1-1% of the total mass of the dihydroxy compound and the plant phenol glycidyl ether; the addition amount of the second catalyst is 0.1-1% of the mass of the intermediate; and the addition amount of the ethylene oxide is 1-10% of the mass of the intermediate.

6. The method for preparing a high-functionality plant phenolic polyether polyol according to claim 4, characterized in that: The first catalyst is selected from any one or more of benzyltrimethylammonium bromide, benzyltriethylammonium bromide, benzyltributylammonium bromide, tetramethylammonium bromide, tetraethylammonium bromide, tetrapropylammonium bromide, tetrabutylammonium bromide, hexadecyltrimethylammonium bromide, boron trifluoride etherate, triphenylphosphine, sodium hydroxide or potassium hydroxide.

7. The method for preparing a high-functionality plant phenolic polyether polyol according to claim 4, characterized in that: The second catalyst is selected from any one or more of an alkali metal catalyst, a double metal cyanide catalyst, and an alkyl aluminum phosphate catalyst.

8. A polyurethane adhesive, characterized in that: The polyol is prepared by using the high-functionality plant phenolic polyether polyol described in any one of claims 1 to 3.

9. The polyurethane adhesive according to claim 8, characterized in that: The mass proportion of the high-functionality plant phenol-based polyether polyol in the polyurethane adhesive is 1-3.5%.

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