Disclosure of Invention
The technical problem to be solved by the invention is to provide the epoxy resin-based fiber composite material and the preparation method thereof, and the epoxy resin-based fiber composite material has the advantages of simple process, energy conservation, low pollution, easy control and suitability for large-scale production.
The technical scheme adopted by the invention for solving the technical problems is to provide a preparation method of an epoxy resin-based fiber composite material, which comprises the following steps: s1: preheating epoxy resin and mixing the preheated epoxy resin with fiber to obtain a first composite system of the epoxy resin and the fiber; s2: adding a curing agent into the first composite system to obtain a second composite system of the curing agent, epoxy resin and fibers; s3: and pouring the second composite system into a mold, and heating and curing to obtain the epoxy resin-based fiber composite material.
Preferably, in the step S1, the preheating temperature of the epoxy resin is 40 ℃ to 60 ℃.
Preferably, the step S1 includes: preheating the epoxy resin, mixing the epoxy resin with the fiber, stirring the mixture until the mixture is uniformly mixed, and then putting the mixture into a vacuum drying oven for vacuumizing to obtain a first composite system of the epoxy resin and the fiber.
Preferably, the step S2 includes: and adding the curing agent into the first composite system, stirring until the curing agent is uniformly mixed, and then putting the mixture into a vacuum drying oven for vacuumizing to obtain a second composite system of the curing agent, the epoxy resin and the fibers.
Preferably, the mass ratio of the curing agent to the epoxy resin is 1:5-1: 3.
Preferably, the step S3 includes: and pouring the second composite system into a mold heated to 60-90 ℃, putting the mold into a drying oven at 60-90 ℃, forming and curing for 20-60 min, and demolding to obtain the epoxy resin-based short fiber composite material.
Preferably, the curing agent is modified isophorone diamine, ethylene diamine, m-phenylenediamine or diethylaminopropylamine.
Preferably, in the step of putting the mixture into a vacuum drying oven for vacuumizing, the temperature of the vacuum drying oven is 30-40 ℃, and the vacuumizing time is 3-8 min.
The invention adopts another technical scheme to solve the technical problems and provides an epoxy resin-based fiber composite material prepared by the method.
Compared with the prior art, the invention has the following beneficial effects: according to the epoxy resin-based fiber composite material and the preparation method thereof provided by the invention, no solvent is added for dilution in the epoxy resin preheating process, and the epoxy resin-based fiber composite material with excellent performance is obtained by controlling the mass ratio of the curing agent to the epoxy resin and the curing temperature, so that the epoxy resin-based fiber composite material has the following advantages: no solvent is used, so that the production cost is reduced, and the environmental pollution is avoided; the solvent is not required to be heated until the solvent is completely volatilized, the production time is short, and the method is efficient and convenient; the epoxy resin and the fiber cannot generate bubbles in the mixing process, the control is easy, the continuous production can be realized, and the obtained epoxy resin-based fiber composite material has excellent performance.
Detailed Description
The present invention will be further described with reference to the following examples.
The invention provides an epoxy resin-based short fiber composite material and a preparation method thereof, which mainly comprises the following steps:
step S1: preheating the epoxy resin and mixing the preheated epoxy resin with the fiber to obtain a first composite system of the epoxy resin and the fiber. (ii) a Wherein the epoxy resin can be E-51 type epoxy resin, bisphenol A type epoxy resin E42, bisphenol A type epoxy resin E44 or bisphenol A type epoxy resin E55, and the fiber can be organic fiber. Specifically, the epoxy resin is put into a blast drying oven for preheating, and the preheating temperature can be 40-60 ℃. Because the epoxy resin is in a sticky paste shape, the epoxy resin has better fluidity after being preheated and is easier to be bonded with the fiber. Taking out the preheated epoxy resin, adding the fiber, stirring until the mixture is uniformly mixed, and then putting the mixture into a vacuum drying oven for vacuumizing, wherein the temperature of the vacuum drying oven is 30-40 ℃, and the vacuumizing time is 3-8 min.
Step S2: and adding a curing agent into the first composite system obtained in the step S1 to obtain a second composite system of the curing agent, the epoxy resin and the fibers. The curing agent can be slowly added into the first composite system according to the mass ratio of 1:5-1:3 of the curing agent to the epoxy resin, and the curing agent is added while stirring and stirred until the curing agent and the epoxy resin are uniformly mixed. And putting the mixture into a vacuum drying oven for vacuumizing again, wherein the temperature of the vacuum drying oven is 30-40 ℃, and the vacuumizing time is 3-8 min. The curing agent can be modified isophorone diamine, ethylene diamine, m-phenylenediamine or diethylaminopropylamine and the like.
Step S3: and (4) pouring the second composite system obtained in the step S2 into a mold, and heating and curing to obtain the epoxy resin-based fiber composite material. Specifically, the second composite system is poured into a mold coated with a release agent heated to 60 ℃ to 90 ℃, and the release agent is not particularly limited as long as it can resist high temperature. And finally, placing the epoxy resin matrix fiber composite material into a drying oven at the temperature of 60-90 ℃, forming and curing for 20-60 min, and demolding to obtain the epoxy resin matrix fiber composite material.
In this embodiment, epoxy resin with model number E-51 and modified isophorone diamine are taken as examples of the curing agent, and for other types of epoxy resin, those skilled in the art can select the corresponding curing agent and the mass ratio of the curing agent to the epoxy resin, the curing temperature, etc. to realize a solventless manufacturing process.
Example 1
Preheating epoxy resin in an air-blast drying oven at the temperature of 40 ℃; and taking out the preheated epoxy resin, adding the fiber, uniformly stirring, putting into a vacuum drying oven at 35 ℃ and vacuumizing for 5min to obtain a first composite system of the epoxy resin and the fiber. Slowly adding modified isophorone diamine into the first composite system according to the mass ratio of the modified isophorone diamine to epoxy resin being 1:3, stirring while adding, stirring until the modified isophorone diamine is uniformly mixed, putting the mixture into a vacuum drying oven at 35 ℃, and vacuumizing for 5min to obtain a second composite system of a curing agent, the epoxy resin and fibers. And pouring the second composite system into a mold which is heated to 70 ℃ and coated with a release agent, putting the mold into a drying oven at 70 ℃, curing and molding for 40min, and demolding to obtain the epoxy resin-based fiber composite material.
Example 2
Preheating epoxy resin in an air-blast drying oven at the temperature of 40 ℃; and taking out the preheated epoxy resin, adding the fiber, uniformly stirring, putting into a vacuum drying oven at 35 ℃ and vacuumizing for 8min to obtain a first composite system of the epoxy resin and the fiber. Slowly adding modified isophorone diamine into the first composite system according to the mass ratio of the modified isophorone diamine to epoxy resin being 1:4, stirring while adding, stirring until the modified isophorone diamine is uniformly mixed, putting the mixture into a vacuum drying oven at 30 ℃, and vacuumizing for 5min to obtain a second composite system of a curing agent, the epoxy resin and fibers. And pouring the second composite system into a mold which is heated to 70 ℃ and coated with a release agent, putting the mold into a drying oven at 70 ℃, curing and molding for 40min, and demolding to obtain the epoxy resin-based fiber composite material.
Example 3
Preheating epoxy resin in an air-blast drying oven at the temperature of 40 ℃; and taking out the preheated epoxy resin, adding the fiber, uniformly stirring, putting into a vacuum drying oven at 35 ℃ and vacuumizing for 3min to obtain a first composite system of the epoxy resin and the fiber. Slowly adding modified isophorone diamine into the first composite system according to the mass ratio of the modified isophorone diamine to epoxy resin being 1:5, stirring while adding, stirring until the modified isophorone diamine is uniformly mixed, putting the mixture into a vacuum drying oven at 40 ℃, and vacuumizing for 5min to obtain a second composite system of a curing agent, the epoxy resin and fibers. And pouring the second composite system into a mold which is heated to 70 ℃ and coated with a release agent, putting the mold into a drying oven at 70 ℃, curing and molding for 40min, and demolding to obtain the epoxy resin-based fiber composite material.
Example 4
Preheating epoxy resin in an air-blast drying oven at the temperature of 40 ℃; and taking out the preheated epoxy resin, adding the fiber, uniformly stirring, putting into a vacuum drying oven at 35 ℃ and vacuumizing for 5min to obtain a first composite system of the epoxy resin and the fiber. Slowly adding modified isophorone diamine into the first composite system according to the mass ratio of the modified isophorone diamine to epoxy resin being 1:4, stirring while adding, stirring until the modified isophorone diamine is uniformly mixed, putting the mixture into a vacuum drying oven at 35 ℃, and vacuumizing for 5min to obtain a second composite system of a curing agent, the epoxy resin and fibers. And pouring the second composite system into a mold which is heated to 60 ℃ and coated with a release agent, putting the mold into a drying oven at 60 ℃, curing and molding for 40min, and demolding to obtain the epoxy resin-based fiber composite material.
Example 5
Preheating epoxy resin in an air-blast drying oven at 50 ℃; and taking out the preheated epoxy resin, adding the fiber, uniformly stirring, putting into a vacuum drying oven at 35 ℃ and vacuumizing for 5min to obtain a first composite system of the epoxy resin and the fiber. Slowly adding modified isophorone diamine into the first composite system according to the mass ratio of the modified isophorone diamine to epoxy resin being 1:4, stirring while adding, stirring until the modified isophorone diamine is uniformly mixed, putting the mixture into a vacuum drying oven at 35 ℃, and vacuumizing for 5min to obtain a second composite system of a curing agent, the epoxy resin and fibers. And pouring the second composite system into a mold which is heated to 70 ℃ and coated with a release agent, putting the mold into a drying oven at 70 ℃, curing and molding for 40min, and demolding to obtain the epoxy resin-based fiber composite material.
Example 6
Preheating epoxy resin in an air-blast drying oven at the temperature of 40 ℃; and taking out the preheated epoxy resin, adding the fiber, uniformly stirring, putting into a vacuum drying oven at 35 ℃ and vacuumizing for 5min to obtain a first composite system of the epoxy resin and the fiber. Slowly adding modified isophorone diamine into the first composite system according to the mass ratio of the modified isophorone diamine to epoxy resin being 1:4, stirring while adding, stirring until the modified isophorone diamine is uniformly mixed, putting the mixture into a vacuum drying oven at 35 ℃, and vacuumizing for 5min to obtain a second composite system of a curing agent, the epoxy resin and fibers. And pouring the second composite system into a mold which is heated to 80 ℃ and coated with a release agent, putting the mold into a drying oven at 80 ℃, curing and molding for 40min, and demolding to obtain the epoxy resin-based fiber composite material.
Example 7
Preheating epoxy resin in an air-blast drying oven at the temperature of 40 ℃; and taking out the preheated epoxy resin, adding the fiber, uniformly stirring, putting into a vacuum drying oven at 35 ℃ and vacuumizing for 5min to obtain a first composite system of the epoxy resin and the fiber. Slowly adding modified isophorone diamine into the first composite system according to the mass ratio of the modified isophorone diamine to epoxy resin being 1:4, stirring while adding, stirring until the modified isophorone diamine is uniformly mixed, putting the mixture into a vacuum drying oven at 35 ℃, and vacuumizing for 5min to obtain a second composite system of a curing agent, the epoxy resin and fibers. And pouring the second composite system into a mold which is heated to 90 ℃ and coated with a release agent, putting the mold into a drying oven at 90 ℃, curing and molding for 40min, and demolding to obtain the epoxy resin-based fiber composite material.
Example 8
Preheating epoxy resin in an air-blast drying oven at the temperature of 40 ℃; and taking out the preheated epoxy resin, adding the fiber, uniformly stirring, putting into a vacuum drying oven at 35 ℃ and vacuumizing for 5min to obtain a first composite system of the epoxy resin and the fiber. According to the mass ratio of 1: and 4, slowly adding the modified isophorone diamine into the first composite system while stirring, stirring until the modified isophorone diamine is uniformly mixed, and putting the mixture into a vacuum drying oven at 35 ℃ for vacuumizing for 5min to obtain a second composite system of the curing agent, the epoxy resin and the fibers. And pouring the second composite system into a mold which is heated to 70 ℃ and coated with a release agent, putting the mold into a drying oven at 70 ℃, curing and molding for 20min, and demolding to obtain the epoxy resin-based fiber composite material.
Example 9
Preheating the epoxy resin in an air-blast drying oven at the temperature of 60 ℃; and taking out the preheated epoxy resin, adding the fiber, uniformly stirring, putting into a vacuum drying oven at 35 ℃ and vacuumizing for 5min to obtain a first composite system of the epoxy resin and the fiber. According to the mass ratio of 1: and 4, slowly adding the modified isophorone diamine into the first composite system while stirring, stirring until the modified isophorone diamine is uniformly mixed, and putting the mixture into a vacuum drying oven at 35 ℃ for vacuumizing for 5min to obtain a second composite system of the curing agent, the epoxy resin and the fibers. And pouring the second composite system into a mold which is heated to 70 ℃ and coated with a release agent, putting the mold into a drying oven at 70 ℃, curing and molding for 40min, and demolding to obtain the epoxy resin-based fiber composite material.
Example 10
Preheating epoxy resin in an air-blast drying oven at the temperature of 40 ℃; and taking out the preheated epoxy resin, adding the fiber, uniformly stirring, putting into a vacuum drying oven at 35 ℃ and vacuumizing for 5min to obtain a first composite system of the epoxy resin and the fiber. According to the mass ratio of 1: and 4, slowly adding the modified isophorone diamine into the first composite system while stirring, stirring until the modified isophorone diamine is uniformly mixed, and putting the mixture into a vacuum drying oven at 35 ℃ for vacuumizing for 5min to obtain a second composite system of the curing agent, the epoxy resin and the fibers. And pouring the second composite system into a mold which is heated to 70 ℃ and coated with a release agent, putting the mold into a drying oven at 70 ℃, curing and molding for 60min, and demolding to obtain the epoxy resin-based fiber composite material.
Therefore, according to the epoxy resin-based fiber composite material and the preparation method thereof provided by the invention, no solvent is added for dilution in the epoxy resin preheating process, and the epoxy resin-based fiber composite material with excellent performance is obtained by controlling the mass ratio of the curing agent to the epoxy resin and the curing temperature, so that the epoxy resin-based fiber composite material has the following advantages: no solvent is used, so that the production cost is reduced, and the environmental pollution is avoided; the solvent is not required to be heated until the solvent is completely volatilized, the production time is short, and the method is efficient and convenient; the epoxy resin and the fiber cannot generate bubbles in the mixing process, the control is easy, the continuous production can be realized, and the obtained epoxy resin-based fiber composite material has excellent performance.
Although the present invention has been described with respect to the preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.