CN-121975443-A - Vanillin-based acid and alkali resistant adhesive as well as preparation method and application thereof

Abstract

The invention provides a vanillin acid and alkali resistant adhesive, and a preparation method and application thereof, and relates to the technical field of adhesives. The vanillin derivative vanillin and acrylic chloride or acrylic acid and acrylic anhydride are used as raw materials to synthesize the vanillin acid and alkali resistant adhesive FMA in one step under alkaline condition, the adhesive is cured by self-crosslinking when heated to 8 h ℃ at 100 ℃, and the adhesive has high bonding effect on stainless steel, aluminum, glass, poplar and bamboo, and also has good acid and alkali resistance. The raw materials of the adhesive can be obtained by oxidative depolymerization of biomass lignin, and compared with a commercial quick-drying adhesive, the adhesive has the advantages of simple components, high bonding strength, no need of curing agent, acid and alkali resistance and industrial application potential.

Inventors

• LI ZHI
• YANG LONG
• DENG SHUDUAN

Assignees

• 西南林业大学

Dates

Publication Date

20260505

Application Date

20260226

Claims (10)

1. 1. The vanillin acid and alkali resistant adhesive is characterized by having a chemical structural formula as follows: the structural formula of the adhesive FMA is shown in the formula I.
2. 2. A method of preparing the adhesive of claim 1, comprising the steps of: The method comprises the steps of taking vanillin as a starting material, taking acryloyl chloride/acrylic acid/acrylic anhydride as reactants, mixing the starting material with the reactants, and synthesizing a compound shown in a formula I by one-step reaction, wherein the specific synthetic route is as follows: 。
3. 3. The method of claim 2, wherein the molar ratio of the starting material to the reactant is 1 (1-1.5).
4. 4. The preparation method of the catalyst according to claim 2, wherein when the reactant is acryloyl chloride, triethylamine or pyridine is used as an acid binding agent for reaction, and the reaction process is controlled to be ice bath, and dichloromethane is used as a solvent, and the reaction time is 5.0-10.0h.
5. 5. The method of claim 2, wherein the reaction is carried out using dicyclohexylcarbodiimide and 4-dimethylaminopyridine as the catalyst, and the reaction temperature is controlled to 50℃and the reaction time is controlled to 24 hours.
6. 6. The preparation method according to claim 2, wherein when the reactant is acrylic anhydride, the reaction is carried out by using 4-dimethylaminopyridine as a catalyst, and the condition is controlled to be stirring at room temperature for 24 hours.
7. 7. The method of claim 2, wherein the petroleum ether is purified by column chromatography using ethyl acetate=10:1 to obtain the final desired compound.
8. 8. The method of claim 2, wherein the initiator is hydroxybenzaldehyde or syringaldehyde.
9. 9. Use of an adhesive according to claim 1 or a preparation according to any one of claims 1 to 8 in an adhesive material.
10. 10. The method of claim 9, wherein the method of using is bonding any one or more of metal, plastic, glass, wood and bamboo substrates with vanillin acid and alkali resistant adhesive.

Description

Vanillin-based acid and alkali resistant adhesive as well as preparation method and application thereof Technical Field The invention relates to the technical field of adhesive preparation, in particular to a self-crosslinkable compound, a preparation method and application thereof. Background The materials to which the structural adhesives bond are typically in an outdoor environment, which requires that the adhesives have high bond strength and aging resistance. Typical structural adhesives are epoxy resins, polyurethane, acrylate, etc., all of which are derived from petrochemicals and are not sustainable. On the other hand, their synthesis is complex and not degradable, and it can bring about great pollution to the environment. In recent years, attention is paid to the development of biomass-based adhesives, and the design of a bio-based, acid and alkali resistant and recyclable adhesive is particularly urgent. Vanillin is used as a limited micromolecular lignin derivative compound prepared based on lignin resources and realizing industrialization, inherits the characteristics of lignin such as an aromatic ring structure, rich in various active oxygen-containing functional groups (hydroxyl groups and aldehyde groups) and the like, simultaneously overcomes the problems of nonuniform structural composition, poor designability of crosslinked netlike macromolecules and the like which are required to be faced when the lignin is directly applied, and on the other hand, plays a special role and receives more and more attention as an intermediate for synthesizing different bio-based polymers, and is nontoxic (can be used as a food additive) and brings a wide application range for the vanillin-based polymers. The polymer prepared based on vanillin realizes deep utilization of lignin resources in a sustainable sense, and improves the economic added value of lignin downstream products in economic benefit. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a self-crosslinking compound, a preparation method and application thereof, and the designed compound has a better self-crosslinking effect, can be cured under heating conditions in an accelerated manner, and can realize a good adhesive effect. In order to achieve the above purpose, the invention is realized by the following technical scheme: A vanillin acid and alkali resistant adhesive, which has a chemical structural formula as follows: ; designated 4-formyl-2-methoxyphenyl acrylate, FMA. The preparation method of the vanillin acid and alkali resistant adhesive comprises the following steps: The method comprises the steps of taking vanillin as a starting material, taking acryloyl chloride/acrylic acid/acrylic anhydride as reactants, mixing the starting material with the reactants, and synthesizing a compound shown in a formula I by one-step reaction, wherein the specific synthetic route is as follows: 。 Preferably, in the preparation method, the molar ratio of the mixture of the starting materials and the reactants is 1 (1-1.5). Preferably, when the reactant is acryloyl chloride, triethylamine or pyridine is used as an acid binding agent for reaction, the reaction process is controlled to be ice bath, dichloromethane is used as a solvent, and the reaction time is 5.0-10.0h. Preferably, when the reactant is acrylic acid, dicyclohexylcarbodiimide and 4-dimethylaminopyridine are used as catalysts for reaction, and the reaction temperature is controlled to be 50 ℃ and the reaction time is controlled to be 24 hours. Preferably, when the reactant is acrylic anhydride, 4-dimethylaminopyridine is used as a catalyst for reaction, and the condition is controlled to be stirred for 24 hours at room temperature. Preferably, the reaction is completed by column chromatography of petroleum ether with ethyl acetate=10:1 to obtain the final desired compound. Preferably, the starter may be replaced with hydroxybenzaldehyde or syringaldehyde. Preferably, the compound is used as an adhesive to bond any one or more substrates of metal, plastic, glass and wood and bamboo. The invention provides a self-crosslinkable compound, a preparation method and application thereof, and has the advantages compared with the prior art that: The invention designs and synthesizes a micromolecular adhesive, which can be slowly self-crosslinked into macromolecules to be solidified at room temperature, and the solidification can be accelerated by heating. Wherein vanillin is used as a starting material, and vanillin is one of lignin degradation products of biomass, and the obtained vanillin-based adhesive (FMA) has the potential of sustainable development. The bonding test results show that the lap shear strength of the composite material to stainless steel, aluminum, glass, poplar and bamboo reaches 8.44, 7.67, 5.21, 1.22 and 1.29 MPa respectively. In addition, the acid-base environment does not influence the adhesive property, and organic solvents such as methylene