阅读说明：本技术 一种微胶囊包覆植酸盐环氧树脂阻燃剂的制备方法 (Preparation method of microcapsule-coated phytate epoxy resin flame retardant ) 是由 徐艳英 李金都 孙肖东 于 2019-10-30 设计创作，主要内容包括：本发明的一种微胶囊包覆植酸盐环氧树脂阻燃剂的制备方法,以可再生资源植酸盐为原料,根据需要取或进行植酸盐制备,采用微胶囊对其进行包覆,改善其在环氧树脂中的分散性,提高阻燃效果。微胶囊包覆原料包括：环氧树脂(E51)、2-甲基-4-乙基咪唑、乙醇、十二烷基苯磺酸钠。将植酸钠与氯化镁在一定条件下反应一段时间,生成物经洗涤、过滤、干燥处理后得到产物A；将环氧树脂与乙醇混合,加入产物A及十二烷基苯磺酸钠,充分搅拌一段时间,加入2-甲基-4-乙基咪唑,在一定条件下反应,生成物经过抽滤、洗涤、干燥后得到产物B。产物B可以充分分散于环氧树脂中,对固化后环氧树脂的力学性能影响较小,可有效提高环氧树脂的阻燃性能。(According to the preparation method of the microcapsule-coated phytate epoxy resin flame retardant, the phytate which is a renewable resource is taken as a raw material or prepared according to needs, and the phytate is coated by the microcapsule, so that the dispersibility of the phytate in epoxy resin is improved, and the flame retardant effect is improved. The microcapsule coating raw materials comprise: epoxy resin (E51), 2-methyl-4-ethylimidazole, ethanol and sodium dodecyl benzene sulfonate. Reacting sodium phytate with magnesium chloride for a period of time under a certain condition, and washing, filtering and drying a product to obtain a product A; mixing epoxy resin and ethanol, adding the product A and sodium dodecyl benzene sulfonate, fully stirring for a period of time, adding 2-methyl-4-ethylimidazole, reacting under a certain condition, and performing suction filtration, washing and drying on a product to obtain a product B. The product B can be fully dispersed in the epoxy resin, has small influence on the mechanical property of the cured epoxy resin, and can effectively improve the flame retardant property of the epoxy resin.)

1. A preparation method of a microcapsule-coated phytate epoxy resin flame retardant is characterized by comprising the following steps:

step 1, according to the mass ratio, epoxy resin: ethanol (1-1.5): 20, mixing the epoxy resin with ethanol, and fully stirring to obtain a product C;

step 2, adding a phytate solid powder A and an emulsifier into a product C, and fully stirring under a heating condition to obtain a product D, wherein the mass ratio of the substance A to the epoxy resin in the step (3) is 1 (7-5), the mass ratio of sodium dodecyl benzene sulfonate to the substance A is 1 (120-90), and the heating temperature is 50-80 ℃;

and 3, adding 2-methyl-4-ethylimidazole into the product D, fully stirring under a heating condition, carrying out suction filtration, washing and drying on the product to obtain the microcapsule coated phytate epoxy resin flame retardant, wherein the mass ratio of the 2-methyl-4-ethylimidazole to the epoxy resin used in the step (3) is 1 (20-25), and the heating temperature is 70-90 ℃.

2. The method for preparing the microencapsulated phytate epoxy resin flame retardant of claim 1, wherein in the step 1, the epoxy resin is e51, e55 or e 44.

3. The preparation method of the microcapsule-coated phytate epoxy resin flame retardant according to claim 1, wherein in the step 1, the stirring time is 1-2 h.

4. The preparation method of the microcapsule-coated phytate epoxy resin flame retardant of claim 1, wherein in the step 2, the heating mode is water bath heating, and the stirring time is 0.5-1 h.

5. The method for preparing the microcapsule-coated phytate epoxy resin flame retardant of claim 1, wherein in the step 2, the emulsifier is sodium dodecyl benzene sulfonate.

6. The method for preparing the microencapsulated phytate epoxy resin flame retardant according to claim 1, wherein in the step 2, the phytate solid powder A is one of sodium phytate, magnesium phytate and aluminum phytate powder, wherein the phytate solid powder A is commercially available in the case of sodium phytate powder, and the phytate solid powder A is prepared in the following manner in the case of magnesium phytate or aluminum phytate:

(1) adding a sodium phytate solution and a magnesium chloride/aluminum chloride solution into a flask with a condenser, heating under the stirring condition, wherein the heating temperature is 80-100 ℃, the heating time is 1-2 hours, uniformly stirring, condensing and refluxing to obtain a colloid, and the feeding molar ratio of the sodium phytate to the magnesium chloride/aluminum chloride solute is 1 (4-7);

(2) and washing, filtering and drying the colloid to obtain a substance A.

7. The preparation method of the microcapsule coated phytate epoxy resin flame retardant according to claim 6, wherein in the step (1), the heating mode is water bath heating, and the stirring time is 1-2 h.

8. The method for preparing the microcapsule-coated phytate epoxy resin flame retardant according to claim 6, wherein in the step (2), the drying manner is heating drying, the drying temperature is 70 ℃, and the drying time is 24 h.

9. The method for preparing the microcapsule-coated phytate epoxy resin flame retardant according to claim 1, wherein in the step 3, the drying manner is heating drying, the drying temperature is 70 ℃, and the drying time is 24 h.

10. The preparation method of the microcapsule-coated phytate epoxy resin flame retardant according to claim 1, wherein the microcapsule-coated phytate epoxy resin flame retardant prepared in the step 3 is used as follows, and the flame retardant is prepared from the following components in percentage by mass: an epoxy resin system (5-10): (90-95), dispersing the flame retardant into an epoxy resin system, and testing shows that compared with pure epoxy resin, the epoxy resin added with the microcapsule coated phytate has the heat release rate peak value reduction amplitude of 30.6-36.22%, the smoke release rate peak value reduction amplitude of 7.13-28.05%, the total heat release reduction amplitude of 13.7-23.04%, the total smoke release rate peak value reduction amplitude of 13.36-27.06%, the CO release rate peak value reduction amplitude of 21.73-49.02%, and CO₂The peak value reduction amplitude of the release rate is 15.49-39.3%, and the strength of the release rate is 80-95% of that of pure epoxy resin.

The technical field is as follows:

the invention belongs to the technical field of materials, and particularly relates to a preparation method of a microcapsule-coated phytate epoxy resin flame retardant.

Background art:

epoxy resin is a thermosetting polymer material, has excellent properties of adhesion, corrosion resistance, insulation, strength and the like, and is widely applied to the fields of aerospace, electronics and electricity and other industries. However, the application of the epoxy resin is greatly limited due to the inflammability of the epoxy resin, so that the flame retardance of the epoxy resin is enhanced, the occurrence and the spread of fire can be effectively reduced, and the research on the flame retardant of the epoxy resin has important significance.

In recent years, since halogen-containing materials cause a series of environmental problems, research and development of halogen-free materials have become a key issue, and a high-efficiency, low-toxicity, low-smoke halogen-free flame retardant is also a research focus. The development of highly effective flame retardants while maintaining or improving their mechanical properties remains a challenge. In recent years, phytic acid extracted from soybeans and cereals (such as corn, wheat and sorghum) is found to have great potential as a polymer flame retardant and has little influence on mechanical properties, the application of phytic acid as a flame retardant has been widely researched, but the application of metal phytate as a flame retardant of epoxy resin is less, and the microcapsule-coated metal phytate as an epoxy resin flame retardant can further enhance the dispersibility of the metal phytate in the epoxy resin and is beneficial to maintaining the original mechanical properties of the epoxy resin, so that the research on the microcapsule-coated metal phytate flame retardant has practical significance.

The invention content is as follows:

the invention aims to overcome the defects in the prior art and provide a method for preparing a microcapsule-coated phytate epoxy resin flame retardant, which comprises the steps of taking renewable resource sodium phytate as a raw material, reacting metal chloride with sodium phytate to synthesize a biological flame retardant phytate (substance A), carrying out microcapsule coating on the substance A to obtain a flame retardant (substance B), and dispersing the substance B into epoxy resin to improve the fire resistance of the epoxy resin and have little influence on the mechanical property.

In order to achieve the purpose, the invention adopts the following technical scheme:

a preparation method of a microcapsule-coated phytate epoxy resin flame retardant comprises the following steps:

step 1, according to the mass ratio, epoxy resin: ethanol (1-1.5): 20, mixing the epoxy resin with ethanol, and fully stirring to obtain a product C;

step 2, adding a phytate solid powder A and an emulsifier into a product C, and fully stirring under a heating condition to obtain a product D, wherein the mass ratio of the substance A to the epoxy resin in the step (3) is 1 (7-5), the mass ratio of sodium dodecyl benzene sulfonate to the substance A is 1 (120-90), and the heating temperature is 50-80 ℃;

and 3, adding 2-methyl-4-ethylimidazole into the product D, fully stirring under a heating condition, carrying out suction filtration, washing and drying on the product to obtain the microcapsule coated phytate epoxy resin flame retardant, wherein the mass ratio of the 2-methyl-4-ethylimidazole to the epoxy resin used in the step (3) is 1 (20-25), and the heating temperature is 70-90 ℃.

In the step 1, the epoxy resin is e51, e55 or e 44.

In the step 1, the stirring time is 1-2 h.

In the step 2, the heating mode is water bath heating, and the stirring time is 0.5-1 h.

In the step 2, the emulsifier is sodium dodecyl benzene sulfonate.

In the step 2, the phytate solid powder A is one of sodium phytate, magnesium phytate or aluminum phytate powder, wherein the phytate solid powder A is purchased from the market when being sodium phytate powder, and is prepared by adopting the following method when being magnesium phytate or aluminum phytate powder:

(1) adding a sodium phytate solution and a magnesium chloride/aluminum chloride solution into a flask with a condenser, heating under the stirring condition, wherein the heating temperature is 80-100 ℃, the heating time is 1-2 hours, uniformly stirring, condensing and refluxing to obtain a colloid, and the feeding molar ratio of the sodium phytate to the magnesium chloride/aluminum chloride solute is 1 (4-7);

(2) washing, filtering and drying the colloid to obtain a substance A;

in the step (1), the sodium phytate solution and the magnesium chloride/aluminum chloride solution are respectively prepared from sodium phytate and magnesium chloride/aluminum chloride, wherein the concentration of the sodium phytate solution is 0.1-1 mol/L, and the concentration of the magnesium chloride/aluminum chloride solution is 0.5-1 mol/L.

In the step (1), heating is carried out in a water bath manner, and the stirring time is 1-2 h.

In the step (2), the drying mode is heating drying, the drying temperature is 70 ℃, and the drying time is 24 hours.

In the step 3, the heating mode is water bath heating, the heating temperature is 70-100 ℃, and the stirring and condensing reflux time is 3-4 h.

In the step 3, the drying mode is heating drying, the drying temperature is 70 ℃, and the drying time is 24 hours.

The application method of the microcapsule-coated phytate flame retardant comprises the following steps of: an epoxy resin system (5-10): (90-95) dispersing the microcapsule-coated phytate flame retardant into an epoxy resin system. Tests prove that compared with pure epoxy resin, the epoxy resin added with the microcapsule coated phytate has the peak value reduction amplitude of heat release rate of 30.6-36.22%, the peak value reduction amplitude of smoke release rate of 7.13-28.05%, the total heat release reduction amplitude of 13.7-23.04%, the peak value reduction amplitude of total smoke release rate of 13.36-27.06%, the peak value reduction amplitude of CO release rate of 21.73-49.02%, and CO₂The peak value reduction amplitude of the release rate is 15.49-39.3%, and the strength of the release rate is 80-95% of that of pure epoxy resin.

The epoxy resin system comprises epoxy resin and a curing agent.

The invention has the beneficial effects that:

1. the epoxy resin flame retardant is prepared from renewable raw materials, has a flame retardant effect, and has small influence on mechanical properties.

2. The epoxy resin flame retardant prepared by the invention has the advantages of low toxicity, high efficiency and environmental protection, takes renewable resources as raw materials, and is beneficial to sustainable development.

3. The preparation method provided by the invention is simple, the conditions are mild, and the purity of the generated flame retardant is higher.

Description of the drawings:

FIG. 1 is a graph of heat release rate for a neat epoxy and an epoxy added with microencapsulated magnesium phytate prepared in example 1;

FIG. 2 is a graph of smoke release rate for neat epoxy and epoxy added with microencapsulated magnesium phytate prepared in example 1;

FIG. 3 is a total heat release profile of a neat epoxy and an epoxy added with microencapsulated magnesium phytate prepared in example 1;

FIG. 4 is a graph of the total smoke release curve for neat epoxy and epoxy added with microencapsulated magnesium phytate prepared in example 1;

FIG. 5 is a CO release rate profile for neat epoxy and epoxy added with microencapsulated magnesium phytate prepared in example 1;

FIG. 6 is CO of pure epoxy resin and epoxy resin added with microencapsulated magnesium phytate prepared in example 1₂A release rate profile;

FIG. 7 is a graph of heat release rate for neat epoxy and for epoxy with the addition of microencapsulated sodium phytate prepared in example 2;

FIG. 8 is a graph of smoke release rate for neat epoxy and for epoxy added with microencapsulated sodium phytate prepared in example 2;

FIG. 9 is a total heat release profile of neat epoxy and an epoxy added with microencapsulated sodium phytate prepared in example 2;

FIG. 10 is a graph of the total smoke release profile of neat epoxy and epoxy added with microencapsulated sodium phytate prepared in example 2;

FIG. 11 is a CO release rate profile for neat epoxy and epoxy added with microencapsulated sodium phytate prepared in example 2;

FIG. 12 is CO of pure epoxy resin and epoxy resin added with sodium phytate microcapsule prepared in example 2₂A release rate profile;

FIG. 13 is a graph of the heat release rate of a neat epoxy and an epoxy added with microencapsulated magnesium phytate prepared in example 3;

FIG. 14 is a graph of smoke release rate for neat epoxy and epoxy added with microencapsulated magnesium phytate prepared in example 3;

FIG. 15 is a total heat release profile of neat epoxy and epoxy added with microencapsulated magnesium phytate prepared in example 3;

FIG. 16 is a graph of the total smoke release profile of neat epoxy and epoxy added with microencapsulated magnesium phytate prepared in example 3;

FIG. 17 is a CO release rate profile for neat epoxy and epoxy added with microencapsulated magnesium phytate prepared in example 3;

FIG. 18 is CO of pure epoxy resin and epoxy resin added with microencapsulated magnesium phytate prepared in example 3₂A release rate profile;

FIG. 19 is a graph of the heat release rate of a neat epoxy and an epoxy added with microencapsulated magnesium phytate prepared in example 4;

FIG. 20 is a graph of smoke release rate for neat epoxy and epoxy added with microencapsulated magnesium phytate prepared in example 4;

FIG. 21 is a total heat release profile of neat epoxy and epoxy added with microencapsulated magnesium phytate prepared in example 4;

FIG. 22 is a graph of the total smoke release profile of neat epoxy and epoxy added with microencapsulated magnesium phytate prepared in example 4;

FIG. 23 is a CO release rate profile for neat epoxy and epoxy added with microencapsulated magnesium phytate prepared in example 4;

FIG. 24 is CO of pure epoxy resin and epoxy resin added with microencapsulated magnesium phytate prepared in example 4₂A release rate profile;

FIG. 25 is a graph showing heat release rate curves of a pure epoxy resin having a peak value of 992.8KW/m and an epoxy resin to which the microencapsulated magnesium phytate prepared in example 5 was added²The peak value of the heat release rate of the epoxy resin added with the flame retardant is 646.0KW/m²。

FIG. 26 is a graph of smoke release rate for neat epoxy and epoxy added with microencapsulated magnesium phytate prepared in example 5;

FIG. 27 is a total heat release profile of neat epoxy and epoxy added with microencapsulated magnesium phytate prepared in example 5;

FIG. 28 is a graph of the total smoke release profile of neat epoxy and epoxy added with microencapsulated magnesium phytate prepared in example 5;

FIG. 29 is a CO release rate profile for neat epoxy and epoxy added with microencapsulated magnesium phytate prepared in example 5;

FIG. 30 is CO of pure epoxy resin and epoxy resin added with microencapsulated magnesium phytate prepared in example 5₂A release rate profile;

FIG. 31 is a graph of the heat release rate of a neat epoxy and an epoxy added with microencapsulated magnesium phytate prepared in example 6;

FIG. 32 is a graph of smoke release rate for neat epoxy and epoxy added with microencapsulated magnesium phytate prepared in example 6;

FIG. 33 is a total heat release profile of neat epoxy and epoxy added with microencapsulated magnesium phytate prepared in example 6;

FIG. 34 is a graph of the total smoke release profile of neat epoxy and epoxy added with microencapsulated magnesium phytate prepared in example 6;

FIG. 35 is a CO release rate profile for neat epoxy and epoxy added with microencapsulated magnesium phytate prepared in example 6;

FIG. 36 is CO of pure epoxy resin and epoxy resin added with microencapsulated magnesium phytate prepared in example 6₂Release rate profile.

The specific implementation mode is as follows:

the present invention will be described in further detail with reference to examples.

In the following examples, the epoxy resin used as a raw material in the preparation of the flame retardant and the epoxy resin used for flame retardation after the preparation are all e51, i.e., pure epoxy resin. The peak value of the heat release rate of the pure epoxy resin is 992.8KW/m²The peak value of the smoke release rate is 0.18179m²/m²Total heat release of 80.3MJ/m²Total smoke release was 1530.3m²/m²The peak value of the CO release rate is 0.03125g/s, and the CO content is₂The peak release rate was 0.49535 g/s.

After the preparation of the microcapsule-coated phytate epoxy resin flame retardant is finished, dispersing the microcapsule-coated phytate epoxy resin flame retardant into an epoxy resin system, wherein the epoxy resin system comprises epoxy resin and a curing agent, and the curing agent is 2-methyl-4-ethylimidazole with the ratio of 100: 4.