Rosin-based composite material preparation method

Abstract

The invention is suitable for the field of composite materials, and provides a preparation method of a basalt fiber reinforced composite material based on a bisphenol A epoxy resin and maleopimaric anhydride blending system. The composite material provided by the invention is composed of bisphenol A epoxy resin, a curing agent, an accelerant and basalt fiber, the curing agent is formed by blending maleopimaric anhydride and methylhexahydrophthalic anhydride, and the use amount of maleopimaric anhydride accounts for 10-30% of the total mass of the curing agent. According to the invention, bisphenol A type epoxy resin and maleopimaric anhydride blending system epoxy resin are prepared, and the epoxy resin and basalt fiber are prepared into the fiber reinforced composite material, so that the mechanical property and the electrical property of the material are improved, and a new choice is provided for the field of electrical environment-friendly materials.

Description

Technical Field

[0001] The invention relates to the field of composite materials, in particular to a method for preparing a basalt fiber composite material based on a blending system of bisphenol A epoxy resin and maleopimaric anhydride. Background Art

[0002] At present, with the intensification of climate warming, secondary disasters have caused huge casualties and property losses, and people's requirements for carbon reduction and environmental protection have become more urgent. More environmentally friendly electrical materials are used in electrical equipment. In recent years, researchers have carried out pilot applications of green and environmentally friendly materials for electrical equipment such as transformers, GIS and power cables. For example, renewable natural ester insulating oil is used in transformers instead of traditional mineral oil, environmentally friendly fluorocarbon gas is used to replace greenhouse gas SF6, and modified polyolefins are used in high-voltage DC cable insulation materials to replace non-degradable cross-linked polyethylene.

[0003] Epoxy resin is widely used in insulation casting of electrical equipment due to its good insulation performance, excellent high temperature resistance and strong adhesion. The raw materials of epoxy resin are basically all derived from petrochemicals, which leads to excessive consumption of petrochemical resources, aggravating the oil crisis and causing pollution to the natural environment, which does not meet the requirements of sustainable development. Therefore, the existing environmental problems have promoted the exploration and research of biomass resources. People are committed to developing green and environmentally friendly electrical insulation materials with excellent performance, reducing the use of petroleum resources from the source of materials, and seeking alternatives to traditional materials.

[0004] Rosin is a common bio-based material derived from pine trees. Its unique rosin acid contains a large hydrogen phenanthrene ring structure and is a commonly used heat-resistant modified monomer in the field of insulating materials. It is widely used to optimize the heat resistance of epoxy resin and unsaturated polyester resin systems. However, while its hydrogen phenanthrene ring structure improves its heat and cold resistance, it also causes a decrease in its mechanical properties. Rosin-modified epoxy resin and fiber composites can effectively enhance the mechanical properties of the material. Summary of the invention

[0005] In view of this, the present invention proposes a method for preparing a rosin-based composite material.

[0006] The technical solution of the present invention is achieved in this way:

[0007] A rosin-based composite material comprises bisphenol A epoxy resin, curing agent maleopimaric anhydride, curing agent methylhexahydrophthalic anhydride, accelerator 2,4,6-tris(dimethylaminomethyl)phenol, and basalt fiber. The bisphenol A epoxy resin model is E-51, and the epoxy value is 0.51.

[0008] Furthermore, based on weight, the maleopimaric anhydride accounts for 10-30 wt % of the total amount of the curing agent, and the methylhexahydrophthalic anhydride accounts for 70-90 wt % of the total amount of the curing agent.

[0009] Furthermore, the preparation method of maleopimaric anhydride is as follows: under nitrogen protection, 302g of rosin, 11.53g of maleic anhydride and 10.57g of catalyst p-toluenesulfonic acid are added to a 2500ml four-necked flask equipped with a condenser, an electric stirrer and a thermometer, the temperature is raised to 140°C, the temperature is maintained for 2h, a Diels-Alder reaction is performed to generate levorotatory pimaric acid, 150ml of glacial acetic acid is added, the temperature is continued to be heated to 180°C, and the temperature is maintained for 3h, the temperature is slowly cooled to 130°C, 100ml of glacial acetic acid is added, and the mixture is mixed evenly for 1h. When the material cools to room temperature, it is further cooled with ice water, and a brown-yellow crude product of maleopimaric anhydride is obtained by suction filtration, which is then recrystallized with petroleum ether and glacial acetic acid for 2-3 times, and white maleopimaric anhydride is obtained after vacuum drying.

[0010] Further, it is characterized by comprising the following steps:

[0011] 1) Pour maleic anhydride, bisphenol A epoxy resin, methyl hexahydrophthalic anhydride and accelerator 2,4,6-tris(dimethylaminomethyl)phenol into a beaker and mix them evenly to obtain a resin glue, and then perform vacuum degassing in a vacuum drying oven at 70°C for 10 minutes;

[0012] 2) Pour the resin glue into the mold, lay the basalt fiber cloth flat, mix the resin and multiple layers of basalt fiber cloth thoroughly and evenly, so that the basalt fiber is impregnated in the resin;

[0013] 3) Place the mold into a flat vulcanizing machine and heat press for 40 minutes;

[0014] 4) Take out the sample and put it into an oven for post-curing for 10 hours to obtain the finished product.

[0015] Furthermore, in step (1), the mixing is carried out by stirring uniformly at a constant temperature of 70° C. in a water bath.

[0016] Furthermore, in step (2), the mold is preheated at 70° C. for 30 minutes.

[0017] Furthermore, in step (3), the hot pressing is performed at 140° C. and a pressure of 10 MPa.

[0018] Furthermore, in step (4), the post-curing is to cure the sample in an oven at 140° C. for 10 hours.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention adopts a blending system of bisphenol A epoxy resin and maleic anhydride and basalt fiber cloth to prepare a fiber-reinforced composite material. The composite material prepared by the present invention has more excellent electrical properties and mechanical properties than pure petroleum-based epoxy resin basalt fiber reinforced composite materials. After electrical and mechanical performance tests, when maleic anhydride accounts for 10wt% of the total amount of curing agent, the leakage current is 37.68μA, the breakdown field strength is 29.86kV / m, and the bending strength is 907.23MPa. The results show that the fiber-reinforced composite material prepared by the present invention has good electrical insulation performance and high mechanical strength, providing a new choice for the field of electrical environmental protection materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is the synthetic route of maleopimaric anhydride. DETAILED DESCRIPTION

[0022] Specific embodiments will be provided below to clearly and completely describe the present invention.

[0023] Example 1

[0024] Step 1, weighing 40 parts of bisphenol A epoxy resin, 27 parts of methyl hexahydrophthalic anhydride, 3 parts of maleopimaric anhydride, and 0.351 parts of accelerator, by mass, and adding them into a beaker;

[0025] Step 2, keep the beaker at a constant temperature of 70°C in a water bath, stir for 10 minutes to mix evenly, and after obtaining the resin glue, perform vacuum degassing treatment in a vacuum drying oven at 70°C for 10 minutes;

[0026] Step 3: After the mold is preheated at 70°C for 30 minutes, the resin glue is poured into the mold, the basalt fiber cloth is laid flat, and the resin and the multiple layers of basalt fiber cloth are fully mixed so that the basalt fiber is impregnated in the resin;

[0027] Step 4, place the mold into a flat vulcanizer, apply a pressure of 10 MPa at 140°C for 40 minutes, take out the sample and place it in an oven, post-cure the sample at 140°C for 10 hours to obtain the finished product.

[0028] Example 2

[0029] Step 1, weighing 40 parts of bisphenol A epoxy resin, 25 parts of methyl hexahydrophthalic anhydride, 6 parts of maleopimaric anhydride, and 0.357 parts of accelerator, by mass, and adding them into a beaker;

[0030] Step 2, keep the beaker at a constant temperature of 70°C in a water bath, stir for 10 minutes to mix evenly, and after obtaining the resin glue, perform vacuum degassing treatment in a vacuum drying oven at 70°C for 10 minutes;

[0031] Step 3: After the mold is preheated at 70°C for 30 minutes, the resin glue is poured into the mold, the basalt fiber cloth is laid flat, and the resin and the multiple layers of basalt fiber cloth are fully mixed so that the basalt fiber is impregnated in the resin;

[0032] Step 4, place the mold into a flat vulcanizer, apply a pressure of 10 MPa at 140°C for 40 minutes, take out the sample and place it in an oven, post-cure the sample at 140°C for 10 hours to obtain the finished product.

[0033] Example 3

[0034] Step 1, weighing 40 parts of bisphenol A epoxy resin, 23 parts of methyl hexahydrophthalic anhydride, 9 parts of maleopimaric anhydride, and 0.363 parts of accelerator, by mass, and adding them into a beaker;

[0035] Step 2, keep the beaker at a constant temperature of 70°C in a water bath, stir for 10 minutes to mix evenly, and after obtaining the resin glue, perform vacuum degassing treatment in a vacuum drying oven at 70°C for 10 minutes;

[0036] Step 3: After the mold is preheated at 70°C for 30 minutes, the resin glue is poured into the mold, the basalt fiber cloth is laid flat, and the resin and the multiple layers of basalt fiber cloth are fully mixed so that the basalt fiber is impregnated in the resin;

[0037] Step 4, place the mold into a flat vulcanizer, apply a pressure of 10 MPa at 140°C for 40 minutes, take out the sample and place it in an oven, post-cure the sample at 140°C for 10 hours to obtain the finished product.

[0038] Comparative Example 1

[0039] Step 1, weigh 40 parts of bisphenol A epoxy resin, 30 parts of methyl hexahydrophthalic anhydride, and 0.345 parts of accelerator, by mass, and add them into a beaker;

[0040] Step 2, keep the beaker at a constant temperature of 70°C in a water bath, stir for 10 minutes to mix evenly, and after obtaining the resin glue, perform vacuum degassing treatment in a vacuum drying oven at 70°C for 10 minutes;

[0041] Step 3: After the mold is preheated at 70°C for 30 minutes, the resin glue is poured into the mold, the basalt fiber cloth is laid flat, and the resin and the multiple layers of basalt fiber cloth are fully mixed so that the basalt fiber is impregnated in the resin;

[0042] Step 4, place the mold into a flat vulcanizer, apply a pressure of 10 MPa at 140°C for 40 minutes, take out the sample and place it in an oven, post-cure the sample at 140°C for 10 hours to obtain the finished product.

[0043] Test Method

[0044] 1. Breakdown test: According to GB / T 1408.1-2016 standard, a power frequency breakdown voltage test is carried out using a spherical electrode in silicone oil. The sample thickness is 1mm, the voltage rise rate is 1kV / s, and the sample has more than 15 breakdown points. The experimental data is analyzed using Weibull distribution.

[0045] 2. Leakage current test: According to DL / T 62217-2012 standard, place the sample on a flat electrode and apply a 12kV voltage for leakage current test, with a voltage rise rate of 1kV / s and a withstand voltage time of 60s.

[0046] 3. Bending test: According to the standard GB / T 1449-2005, the bending properties of the sample are measured using a universal testing machine. The sample is tested more than five times to obtain the average value.

[0047] The breakdown voltage test, leakage current test and bending test were performed on Examples 1 to 3 and Comparative Example 1. The results are shown in Table 1.

[0048] Table 1

[0049]

[0050] The experimental results in Table 1 show that when maleopimaric anhydride accounts for 10wt% of the total curing agent, the mechanical properties are optimal, with a bending strength of 907.23MPa. Compared with the composite material prepared by pure methylhexahydrophthalic anhydride curing agent, the electrical properties are also better, with a breakdown field strength of 29.86kV / m and a leakage current of 37.68μA. While saving petrochemical resources and protecting the environment, it also has good electrical and mechanical properties and is suitable for the manufacture of environmentally friendly power equipment.

[0051] As described above, the present invention has been described in detail. Obviously, as long as the modifications do not substantially deviate from the inventive point and effect of the present invention and are obvious to those skilled in the art, they are also included in the protection scope of the present invention.

Claims

1. A method for preparing a composite material based on rosin, characterized in that: The invention comprises bisphenol A epoxy resin, curing agent maleopimaric anhydride, curing agent methylhexahydrophthalic anhydride, accelerator 2,4,6-tris(dimethylaminomethyl)phenol and basalt fiber, wherein the maleopimaric anhydride accounts for 10-30wt% of the total curing agent by weight.

2. The method for preparing a rosin-based composite material according to claim 1, characterized in that: The following steps are involved: 1) Pour maleic anhydride, bisphenol A epoxy resin, methyl hexahydrophthalic anhydride and accelerator 2,4,6-tris(dimethylaminomethyl)phenol into a beaker and mix them evenly to obtain a resin glue, and then perform vacuum degassing in a vacuum drying oven at 70°C; 2) Pour the resin glue into the mold, lay the basalt fiber cloth flat, mix the resin and multiple layers of basalt fiber cloth thoroughly and evenly, so that the basalt fiber is impregnated in the resin; 3) Place the mold into a flat vulcanizer and hot press for 40 minutes. Take out the sample and place it in an oven for post-curing for 10 hours to obtain the finished product.

3. According to the preparation method of the rosin-based composite material according to claim 1, the raw materials include 40 parts of bisphenol A epoxy resin, 23-27 parts of methylhexahydrophthalic anhydride, 3-9 parts of maleopimaric anhydride, and 0.35-0.36 parts of accelerator 2,4,6-tris(dimethylaminomethyl)phenol, by mass.

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