A water-resistant quaternary ammonium salt / epoxy thermosetting material and preparation method thereof

Abstract

The invention discloses a water-resistant quaternary ammonium salt / epoxy thermosetting material and a preparation method thereof, comprising the following steps: adding epoxy resin and halogenated acetic acid into a reactor, stirring and reacting at 100°C to 150°C for 1 to 30 hours; extracting, drying, decompressing and distilling to obtain a halogenated acetic acid ester epoxy resin after the reaction is completed; mixing a polyacrylate compound with a methyl-free dialkylamine for reaction; after the reaction is completed, decompressing and distilling to obtain a tri(dialkylamine) compound curing agent; uniformly mixing the halogenated acetic acid ester epoxy resin obtained in step (1) and the tri(dialkylamine) compound curing agent obtained in step (2), putting the mixture into a mold for curing, and obtaining the water-resistant quaternary ammonium salt / epoxy thermosetting material. The synthesis of the water-resistant quaternary ammonium salt / epoxy thermosetting system has the characteristics of simple process, high conversion rate, high yield, etc., and is resistant to water swelling and has a bactericidal effect.

Description

Technical Field

[0001] The invention relates to a method for preparing a water-resistant quaternary ammonium salt / epoxy thermosetting material, in particular to a thermosetting system containing a water-resistant quaternary ammonium root structure. Background Art

[0002] With the continuous development of science and technology and the continuous increase of global population, people's demand for plastics is also increasing. Among them, materials containing quaternary ammonium salt structures are more favored. Generally speaking, quaternary ammonium salts are composed of hydrophilic ammonium cations and hydrophobic alkyl chains of different lengths. When the resin contains quaternary ammonium salt ion structure, its mechanical strength can be improved to a certain extent. In addition, quaternary ammonium salts can kill bacteria due to interaction with cell membranes. The principle is as follows: hydrophobic chains are incorporated into the lipid bilayer structure of cell membranes, interact with negatively charged phospholipids, and cause inhibition or denaturation of cell membrane proteins, thereby causing leakage of substances in the cell membrane, thereby achieving a bactericidal effect. Although quaternary ammonium salt polymers have such advantages, the structure has poor tolerance to water, is very easy to absorb water and swell, and has obvious performance degradation, which is not conducive to long-term use.

[0003] Thermosetting epoxy resins are widely used in coatings, adhesives, composite material reinforcement matrix and other fields due to their excellent mechanical properties, electrical insulation properties and chemical solvent resistance. However, thermosetting epoxy resins do not have antibacterial effects, and the mechanical properties of different epoxy resins after curing are also quite different. In order to improve the mechanical strength and antibacterial effect of epoxy resins, quaternary ammonium salt structures can be introduced into their molecular structures. However, quaternary ammonium salt / epoxy resin thermosetting systems often face the dilemma of being not resistant to water. This is actually caused by the widespread use of dimethyl tertiary amine to prepare quaternary ammonium salts, and the resulting dimethyl quaternary ammonium root has strong water absorption. Summary of the invention

[0004] The object of the present invention is to provide a method for preparing a water-resistant quaternary ammonium salt / epoxy thermosetting material.

[0005] In order to achieve the above objectives, the following technical solutions are provided:

[0006] A method for preparing a water-resistant quaternary ammonium salt / epoxy thermosetting material comprises the following steps:

[0007] (1) Add epoxy resin and halogenated acetic acid into a reactor and stir and react them at 100° C. to 150° C. for 1 to 30 hours. After the reaction is completed, extract, dry, distill under reduced pressure, and dry again to obtain a multifunctional halogenated acetic acid ester epoxy resin.

[0008] (2) reacting the polyacrylate compound with a methyl-free dialkylamine at 15 to 50° C. for 24 to 72 hours. After the reaction is completed, distilling under reduced pressure and drying to obtain a pure tri(dialkylamine) compound curing agent.

[0009] (3) The halogenated acetate epoxy resin and the tri(dialkylamino) compound curing agent are uniformly mixed and placed in a mold for curing. The curing is divided into three stages to obtain a water-resistant quaternary ammonium salt / epoxy thermosetting material.

[0010] In the above technical scheme, preferably, the epoxy resin is selected from phenolic epoxy resin, bisphenol A epoxy resin, bisphenol F epoxy resin, hydrogenated bisphenol A epoxy resin, glycerol triglycidyl ether, epoxidized soybean oil, polyphenol type glycidyl ether epoxy resin, aliphatic glycidyl ether epoxy resin, glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, cyanuric acid epoxy resin, hydantoin epoxy resin, but is not limited thereto.

[0011] Preferably, the multi-acrylate compound is selected from trimethylolpropane diacrylate, trimethylolpropane triacrylate, trimethylolpropane tetraacrylate, di-trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, 2,2-di(hydroxymethyl)-1,3-propane diyl diacrylate, propoxylated trimethylolpropane triacrylate, and polyalkoxylated trimethylolpropane (meth)acrylate.

[0012] Preferably, the methyl-free dialkylamine is selected from diethylamine, dipropylamine, diisopropylamine, dibutylamine, diisobutylamine, dipentylamine, diisopentylamine, dineopentylamine, dihexylamine, diisohexylamine, dioctylamine, diisooctylamine and dineoctylamine.

[0013] Preferably, the halogenated acetic acid is selected from chloroacetic acid, bromoacetic acid and iodoacetic acid.

[0014] Preferably, the molar ratio of the epoxy resin to the halogenated acetic acid is 1:(3.5-5).

[0015] Preferably, the molar ratio of the polyacrylate compound to the methyl-free dialkylamine is 1:(2.5-4).

[0016] Preferably, the molar ratio of the halogenated acetate epoxy resin to the tri(dialkylamine) compound curing agent is 1:(0.5-1).

[0017] Preferably, the curing conditions are divided into three stages: pre-curing, curing and post-curing, wherein the pre-curing conditions are 60-100°C for reaction for 1-4 hours, the curing conditions are 80-130°C for reaction for 6-12 hours, and the post-curing conditions are 120°C-170°C for reaction for 1-8 hours.

[0018] The present invention is based on experimental results and finds that when the tertiary amine does not have a methyl group but has an alkyl group with a carbon number greater than 2, the alkyl group can effectively shield the polarity of the ammonium radical, greatly reducing the water absorption of the system. The water-resistant quaternary ammonium salt / epoxy thermosetting system synthesized by the present invention contains an ether bond, a benzene ring and a betaine ester quaternary ammonium salt group. The product is a compound having multiple ester bonds formed by ring-opening esterification of the carboxyl group of chloroacetic acid and the epoxy group in the epoxy resin, and then directly mixed with multiple tertiary amines for quaternization reaction, and cured in a mold. The compound synthesized by the invention has a faster curing speed and can achieve long-lasting resistance to water swelling in neutral water (pH=7.0).

[0019] The beneficial effects of the present invention are:

[0020] The synthesis of the water-resistant quaternary ammonium salt / epoxy thermal curing system has the characteristics of simple process, high conversion rate, high yield, etc. The material has good anti-water swelling effect, and at the same time has a bactericidal effect due to the betaine ester quaternary ammonium salt group, which is not available in other similar quaternary ammonium salt / epoxy resin materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is the nuclear magnetic resonance image of the chloroacetyl epoxy resin obtained by reacting bisphenol F epoxy resin with chloroacetic acid in Example 2 of the present invention, A) is its hydrogen spectrum, and B) is its carbon spectrum;

[0022] Figure 2 is the NMR spectrum of tri(diethylamino)trimethylolpropane triacrylate in Example 2 of the present invention, A) is its hydrogen spectrum, and B) is its carbon spectrum;

[0023] Figure 3 These are swelling test diagrams of two resins in water, a is the product in Example 2 of the present invention, and b is the product in Example 3 of the present invention (100 mg sample, pH=7.0, room temperature). DETAILED DESCRIPTION

[0024] The principle of the invention is to mix a poly-tertiary amine compound with a chloroacetate epoxy resin containing multiple halogens to cause a quaternization reaction to generate an epoxy resin material containing a betaine ester quaternary ammonium salt group.

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments, and the purpose and effects of the present invention will become more apparent.

[0026] Embodiment 1:

[0027] Novolac epoxy resin (100.00 g, 0.294 mol) and bromoacetic acid (122.554 g, 0.882 mol) were added to the reactor in sequence, and the mixture was stirred at 100° C. for 24 hours. After the reaction, a multifunctional bromoacetate epoxy resin was obtained by extraction, drying, vacuum distillation and drying.

[0028] Trimethylolpropane triacrylate (29.6 g, 0.1 mol) and diethylamine (32.85 g, 0.45 mol) were added to the reactor in sequence and stirred at 40° C. for 48 h. After the reaction was completed, tri(diethylamino)trimethylolpropane triacrylate was obtained by extraction, drying, vacuum distillation and drying.

[0029] The multifunctional bromoacetate epoxy resin (10.00 g, 0.003 mol) and tri(diethylamino)trimethylolpropane triacrylate (4.889 g, 0.009 mol) were mixed evenly, put into a mold, and cured at 65°C for 2 hours, 80°C for 6 hours, and 120°C for 2 hours to obtain the final product.

[0030] Embodiment 2:

[0031] Bisphenol F epoxy resin (100.00 g, 0.294 mol) and chloroacetic acid (83.38 g, 0.882 mol) were added to the reactor in sequence, and the mixture was stirred at 100° C. for 30 hours. After the reaction, a multifunctional chloroacetyl epoxy resin was obtained by extraction, drying, vacuum distillation and drying.

[0032] The preparation process of tri(diethylamino)trimethylolpropane triacrylate is shown in Example 1.

[0033] The multifunctional chloroacetate epoxy resin (10.00 g, 0.004 mol) and tri(diethylamino)trimethylolpropane triacrylate (6.315 g, 0.012 mol) were mixed evenly, put into a mold, and cured at 95°C for 2 hours, 130°C for 6 hours, and 155°C for 4 hours to obtain the final product.

[0034] The whole reaction process can be expressed as follows:

[0035]

[0036] (In the formula, the substance below the single arrow is an abbreviation of the substance above.)

[0037] Embodiment 3:

[0038] Bisphenol A epoxy resin (100.00 g, 0.339 mol) and chloroacetic acid (80.08 g, 0.848 mol) were added to the reactor in sequence, and the mixture was stirred at 100° C. for 18 hours. After the reaction, a multifunctional chloroacetyl epoxy resin was obtained by extraction, drying, vacuum distillation and drying.

[0039] The preparation process of tri(dipropylamino)trimethylolpropane triacrylate is shown in Example 1.

[0040] Mix multifunctional chloroacetate epoxy resin (10.00 g, 0.003 mol) and tri(dibutylamino)trimethylolpropane tetraacrylate (3.514 g, 0.005 mol) evenly, put into a mold, cure at 95°C for 2 h, 130°C for 10 hours, and 155°C for 6 hours to obtain the final product.

[0041] Embodiment 4:

[0042] Epoxidized soybean oil (100.00 g, 0.102 mol) and chloroacetic acid (24.098 g, 0.255 mol) were added to the reactor in sequence, and the mixture was stirred at 100° C. for 20 hours. After the reaction, the multifunctional chloroacetyl epoxy resin was obtained by extraction, drying, vacuum distillation and drying.

[0043] Ditrimethylolpropane tetraacrylate (96.4 g, 0.1 mol) and dibutylamine (58.05 g, 0.45 mol) were added to the reactor in sequence and stirred at 40° C. for 48 h. After the reaction was completed, bis-tri(dibutylamino)trimethylolpropane tetraacrylate was obtained by extraction, drying, vacuum distillation and drying.

[0044] Mix multifunctional chloroacetate epoxy resin (10.00 g, 0.008 mol) and bis-tri(dibutylamino)trimethylolpropane tetraacrylate (5.981 g, 0.005 mol) evenly, put into a mold, cure at 95°C for 2 hours, 130°C for 12 hours, and 165°C for 4 hours to obtain the final product.

[0045] Although the quaternary ammonium salt epoxy thermosetting resin prepared by the present invention contains betaine ester groups which are widely believed to be easily hydrolyzed, the tertiary amine curing agent used in the resin preparation process does not have a methyl group, but an ethyl group with a carbon number of 2. Figure 3 It can be seen that the resin prepared in Example 2 and Example 3 can still maintain a relatively complete appearance after 180 days in water with a pH of 7.0 without swelling, indicating that the resin has high water resistance.

[0046] The above specific implementation modes are used to explain the present invention rather than to limit the present invention. Any modification and change made to the present invention within the spirit of the present invention and the protection scope of the claims shall fall within the protection scope of the present invention.

Claims

1. A method for preparing a water-resistant quaternary ammonium salt / epoxy thermosetting material, characterized in that: The following steps are involved: (1) adding epoxy resin and halogenated acetic acid into a reactor, stirring and reacting at 100° C. to 150° C. for 1 to 30 hours; after the reaction is completed, extracting, drying, distilling under reduced pressure, and drying again to obtain a halogenated acetic acid ester epoxy resin; the epoxy resin is selected from phenolic epoxy resin and bisphenol F epoxy resin, and the halogenated acetic acid is selected from chloroacetic acid and bromoacetic acid; (2) reacting a polyacrylate compound with a methyl-free dialkylamine at 15 to 50° C. for 24 to 72 hours, and after the reaction is completed, distilling under reduced pressure and drying to obtain a tri(dialkylamino) compound curing agent; the polyacrylate compound is trimethylolpropane triacrylate, the methyl-free dialkylamine is diethylamine, and the tri(dialkylamino) compound curing agent is tri(diethylamino)trimethylolpropane triacrylate; (3) The halogenated acetate epoxy resin obtained in step (1) and the tri(dialkylamino) compound curing agent obtained in step (2) are uniformly mixed and cured in stages to obtain the water-resistant quaternary ammonium salt / epoxy thermosetting material.

2. The method for preparing the water-resistant quaternary ammonium salt / epoxy thermosetting material according to claim 1, characterized in that: In step (1), the molar ratio of the epoxy resin to the halogenated acetic acid is 1:(3.5-5).

3. The method for preparing the water-resistant quaternary ammonium salt / epoxy thermosetting material according to claim 1, characterized in that: In step (2), the molar ratio of the polyacrylate compound to the methyl-free dialkylamine is 1:(2.5-4).

4. The method for preparing the water-resistant quaternary ammonium salt / epoxy thermosetting material according to claim 1, characterized in that: In step (3), the molar ratio of the halogenated acetate epoxy resin to the tri(dialkylamino) compound curing agent is 1:(0.5-1).

5. The method for preparing the water-resistant quaternary ammonium salt / epoxy thermosetting material according to claim 1, characterized in that: In step (3), the staged curing includes three stages: pre-curing, curing, and post-curing. The pre-curing condition is 60-100°C for reaction for 1-4 hours, the curing condition is 80-130°C for reaction for 6-12 hours, and the post-curing condition is 120°C-170°C for reaction for 1-8 hours.

6. A water-resistant quaternary ammonium salt / epoxy thermosetting material, characterized in that: The method is prepared according to any one of claims 1 to 5.

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