A kind of epoxy resin that cures quickly at low temperature and its preparation method and application

Abstract

A low-temperature fast-curing epoxy resin and a preparation method and application thereof, wherein the reaction is carried out at 80-150°C for 1-10 h according to a molar ratio of vanillin to polyglycidyl ether of 1:1-1:1.2 to obtain a vanillin-based epoxy monomer; polyethyleneimine is used as a curing agent; and the vanillin-based epoxy monomer and the curing agent are stirred and mixed at a mass ratio of 3:(1-5) to obtain a low-temperature vanillin-based fast-curing resin. The invention uses biomass as a raw material, has simple synthesis steps, and the prepared epoxy resin can be instantly gel-cured at -20°C, and double cross-linking makes the cured resin have excellent mechanical properties.

Description

Technical Field

[0001] The invention relates to the field of epoxy resins, and in particular to an epoxy resin that cures quickly at low temperatures, and a preparation method and application thereof. Background Art

[0002] Epoxy resin is a high molecular polymer with the molecular formula (C 11 H 12 O3) n , refers to a general term for a class of polymers containing more than two epoxy groups in the molecule. It is the condensation product of epichlorohydrin and bisphenol A or polyol. Due to the chemical activity of the epoxy group, it can be opened with a variety of compounds containing active hydrogen, cured and cross-linked to form a network structure, so it is a thermosetting resin. Bisphenol A type epoxy resin not only has the largest output and the most complete variety, but also new modified varieties are still increasing and the quality is constantly improving. The excellent physical, mechanical and electrical insulation properties of epoxy resin, the bonding properties with various materials, and the flexibility of its use process are not possessed by other thermosetting plastics. Therefore, it can be made into coatings, composite materials, casting materials, adhesives, molding materials and injection molding materials, and is widely used in various fields of the national economy. At present, epoxy resin composite materials are mostly cured and molded at medium and high temperature (120-180℃) and medium and low temperature (70-90℃). The high energy consumption, long molding cycle, temperature-resistant tooling and auxiliary materials brought about by heating and curing all increase the manufacturing cost. In addition, some environments that cannot meet heating conditions will also limit the application of epoxy resins. There is still little research on low-temperature curing epoxy resin materials. The research on low-temperature curing agents mainly focuses on polythiols and thioureas. Polythiols are expensive and mainly rely on imports. Polythiols and thioureas both have unpleasant odors and are highly toxic. Therefore, it is of great significance to develop low-temperature fast-curing epoxy resins for reinforcement and plugging projects in low-temperature environments. Summary of the invention

[0003] Technical problem to be solved: In view of the above technical problem, the present invention provides an epoxy resin that cures quickly at low temperature and a preparation method and application thereof.

[0004] Technical solution: A method for preparing an epoxy resin that cures quickly at low temperature, comprising the following steps: reacting at 80-150°C for 1-10 hours at a molar ratio of vanillin:polyglycidyl ether of 1:(1-1.2) to obtain a vanillin-based epoxy monomer; using polyethyleneimine as a curing agent, stirring and mixing at a mass ratio of vanillin-based epoxy monomer to curing agent of 3:(1-5), and forming the mixture within 5 minutes to obtain an epoxy resin.

[0005] The above-mentioned polyglycidyl ether is glycerol triglycidyl ether or pentaerythritol tetraglycidyl ether.

[0006] The molar ratio of the vanillin to the polyglycidyl ether is 1:1.

[0007] An accelerator is added during the preparation of the vanillin-based epoxy monomer, and the accelerator is triethylbenzylammonium chloride or 2,4,6-tris(dimethylaminomethyl)phenol.

[0008] An antioxidant is added during the preparation of the vanillin-based epoxy monomer, and the antioxidant is 1010 or 1076.

[0009] The epoxy resin prepared by the above method.

[0010] The above epoxy resin is used in the preparation of reinforcement and plugging materials in low temperature environments.

[0011] Beneficial effects: 1) The present invention provides a method for preparing an epoxy resin that can be quickly cured at low temperatures. 2) The prepared epoxy resin can be quickly cured at low temperatures. 3) The raw material vanillin is green and environmentally friendly, the preparation process is simple, and it is easy to achieve large-scale production. 4) The present invention has a significant significance for the high-value utilization of biomass resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is an infrared spectrum of the vanillin-based epoxy monomer prepared according to Example 1;

[0013] Figure 2 The NMR spectrum of the vanillin-based epoxy monomer prepared according to Example 1. DETAILED DESCRIPTION

[0014] The present invention is described in detail below by examples, and the examples provide detailed implementation methods and specific operation steps, which are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. The present invention is not limited to the above-mentioned specific implementation methods, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essential content of the present invention.

[0015] Example 1

[0016] Preparation of vanillin-based epoxy monomer: Weigh 50g of vanillin and 50.2g of glycerol triglycidyl ether into a three-necked flask, then add 1.1g of triethylbenzyl ammonium chloride as an accelerator, and then add 0.33g of antioxidant 1010, stir, react at 100°C for 3h, and cool to room temperature after the reaction to obtain vanillin-based epoxy monomer. Weigh 50g of vanillin-based epoxy monomer and 30g of polyethyleneimine 600 curing agent, stir evenly, and the resulting mixture can be quickly cured and formed within 5 minutes at a low temperature of -20°C.

[0017] Example 2

[0018] Preparation of vanillin-based epoxy monomer: Weigh 50g of vanillin and 118.5g of pentaerythritol tetraglycidyl ether into a three-necked flask, then add 1.2g of triethylbenzyl ammonium chloride as an accelerator, and then add 0.33g of antioxidant 1010, stir, react at 90°C for 3h, and cool to room temperature after the reaction to obtain vanillin-based epoxy monomer. Weigh 50g of vanillin-based epoxy monomer and 40g of polyethyleneimine 600 curing agent, stir evenly, and the resulting mixture can be quickly cured and formed within 5 minutes at a low temperature of -20°C.

[0019] Example 3

[0020] Preparation of vanillin-based epoxy monomer: Weigh 50g of vanillin and 50.2g of glycerol triglycidyl ether into a three-necked flask, then add 1.1g of triethylbenzyl ammonium chloride as an accelerator, and then add 0.33g of antioxidant 1010, stir, react at 100°C for 3h, and cool to room temperature after the reaction to obtain vanillin-based epoxy monomer. Weigh 50g of vanillin-based epoxy monomer and 25g of polyethyleneimine 1800 curing agent, stir evenly, and the resulting mixture can be quickly cured and formed within 5 minutes at a low temperature of -20°C.

[0021] Example 4

[0022] Preparation of vanillin-based epoxy monomer: Weigh 50g of vanillin and 50.2g of glycerol triglycidyl ether into a three-necked flask, then add 1.1g of triethylbenzyl ammonium chloride as an accelerator, and then add 0.33g of antioxidant 1010, stir, react at 100°C for 3h, and cool to room temperature after the reaction to obtain vanillin-based epoxy monomer. Weigh 50g of vanillin-based epoxy monomer and 20g of polyethyleneimine 10000 curing agent, stir evenly, and the resulting mixture can be quickly cured and formed within 3 minutes at a low temperature of -20°C.

[0023] Example 5

[0024] Preparation of vanillin-based epoxy monomer: Weigh 50g of vanillin and 118.5g of pentaerythritol tetraglycidyl ether into a three-necked flask, then add 1.2g of triethylbenzyl ammonium chloride as an accelerator, and then add 0.33g of antioxidant 1010, stir, react at 90°C for 3h, and cool to room temperature after the reaction to obtain vanillin-based epoxy monomer. Weigh 50g of vanillin-based epoxy monomer and 35g of polyethyleneimine 1800 curing agent, stir evenly, and the resulting mixture can be quickly cured and formed within 5 minutes at a low temperature of -20°C.

[0025] Example 6

[0026] Preparation of vanillin-based epoxy monomer: Weigh 50g of vanillin and 118.5g of pentaerythritol tetraglycidyl ether into a three-necked flask, then add 1.2g of triethylbenzyl ammonium chloride as an accelerator, and then add 0.33g of antioxidant 1010, stir, react at 90°C for 3h, and cool to room temperature after the reaction to obtain vanillin-based epoxy monomer. Weigh 50g of vanillin-based epoxy monomer and 35g of polyethyleneimine 10000 curing agent, stir evenly, and the resulting mixture can be quickly cured and formed within 2 minutes at a low temperature of -20°C.

[0027] The following table shows the performance parameters of the latent resin system prepared in Examples 1-2 of the present invention.

[0028] Example 1 Example 2 Tensile strength(MPa) 0.12 0.16 Tensile strain at break (%) 32.3 28.5

Claims

1. A method for preparing an epoxy resin that cures rapidly at low temperatures, characterized in that: Preparation of vanillin-based epoxy monomer: weigh 50 g of vanillin and 50.2 g of glycerol triglycidyl ether into a three-necked flask, then add 1.1 g of triethylbenzyl ammonium chloride as a promoter, and then add 0.33 g of antioxidant 1010, stir, and react at 100 °C for 3 h. After the reaction is completed, cool to room temperature to obtain a vanillin-based epoxy monomer; weigh 50 g of vanillin-based epoxy monomer and 30 g of polyethyleneimine 600 curing agent, stir evenly, and the resulting mixture can be quickly cured and formed within 5 minutes at a low temperature of -20 °C.

2. The epoxy resin prepared by the method according to claim 1.

3. Use of the epoxy resin according to claim 2 in preparing reinforcement and plugging materials in low temperature environments.

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