High-modulus and high-toughness epoxy resin and preparation method thereof

Abstract

The invention discloses high-modulus and high-toughness epoxy resin and a preparation method thereof. The high-modulus and high-toughness epoxy resin comprises 40-80 parts of an epoxy resin component, 5-25 parts of a thermoplastic resin component, 10-30 parts of a curing agent component, 1-5 parts of a reinforcing agent component and 3-10 parts of a toughening agent component. The resin provided by the invention has better toughness and heat resistance while meeting the high modulus of epoxy resin, is beneficial to improving the compression strength and interlaminar shear performance of the material, can effectively solve the problems of compression resistance and layering when the composite material is used as a main bearing component, and has the advantages of convenience in operation, good repeatability and the like.

Description

Technical Field

[0001] The present invention relates to the field of composite material preparation, and more particularly to a high-modulus and high-toughness epoxy resin and a preparation method thereof. Background Art

[0002] The application of carbon fiber reinforced epoxy resin composites can significantly reduce the weight of high-end equipment. In the past few decades, the longitudinal tensile strength of the material has been greatly improved, but the compression strength has been improved very little. At the same time, for sustainable development, there is a more urgent need for reusable equipment, which requires materials with high toughness and resistance to fatigue and impact.

[0003] There are many factors that affect the compression performance and toughness of carbon fiber composites. They are not only affected by the tensile properties of fiber multifilaments, fiber volume content, fiber-resin matrix interface bonding strength, fiber alignment and molding process, but also by the properties of the resin matrix. A high-modulus and high-toughness epoxy resin matrix can make the composite material have higher compression strength and post-impact compression strength.

[0004] In order to address the shortcomings of existing composite materials such as low compression-to-tension ratio, low modulus, and poor toughness, the present invention has developed a high-modulus and high-toughness resin matrix, breaking through the key technology of synergistically improving the compression and toughness properties of composite materials, and effectively supporting the development of a new generation of advanced composite materials with both high modulus and high toughness. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a high-modulus and high-toughness epoxy resin and a preparation method thereof.

[0006] In order to solve the above technical problems, the present invention mixes tetrafunctional epoxy resin or trifunctional epoxy resin, thermoplastic resin, reinforcing agent, toughening agent and meta-curing agent in a certain range of proportions to prepare an epoxy resin matrix, thereby achieving the purpose of the present invention.

[0007] In a first aspect, the present invention relates to a high modulus and high toughness epoxy resin, wherein the content of each component is, in parts by weight:

[0008] Epoxy resin component: 40-80;

[0009] Thermoplastic resin component: 5-25;

[0010] Curing agent component: 10-30;

[0011] Enhancer component: 1 to 5;

[0012] Toughening agent component: 3 to 10.

[0013] Furthermore, the epoxy resin component is a high-functionality resin with an epoxy functionality greater than or equal to 3, specifically a mixture of one or more of AG80, AFG90H, and TDE-85.

[0014] Furthermore, the thermoplastic resin component is a high molecular weight thermoplastic resin, specifically one or a mixture of at least two of polyarylethersulfone, polyaryletherketone and polyetherimide with an average molecular weight of ≥50,000.

[0015] Furthermore, the curing agent component is an amine curing agent, specifically one of 3,3-diaminodiphenyl sulfone and meta-phenylenediamine, or a mixture of two of them.

[0016] Furthermore, the reinforcing agent component is one or a mixture of nano-silicon dioxide and carbon nanotubes.

[0017] Furthermore, the toughening agent component is nano core-shell rubber, and the particle size is required to be 100-300nm.

[0018] In a second aspect, the present invention relates to a method for preparing the high modulus and high toughness epoxy resin, the steps of which are as follows:

[0019] 1) Take a portion of the epoxy resin component, add the thermoplastic resin component, heat to 100-130°C, mix and stir to dissolve evenly, and prepare component A;

[0020] 2) taking the remaining epoxy resin component, adding the reinforcing agent component, the toughening agent component and the curing agent component respectively, stirring evenly, and then pouring into a three-roll grinder and grinding to obtain component B;

[0021] 3) Mix component A and component B evenly at 60-70°C to obtain a high-modulus and high-toughness epoxy resin.

[0022] Furthermore, the pouring into the three-roll mill and grinding is performed at least 10 times.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] (1) The present invention uses an epoxy resin with a functionality greater than or equal to 3, which has a high functionality and a large cross-linking density after curing, so that the cured product has a higher strength and modulus; in addition, the curing agent is an amine meta-type curing agent, and the meta-substituted structure has a higher conformational freedom during curing, which is conducive to forming a tighter molecular stacking, thereby improving the strength and modulus of the cured product; finally, after the addition of nano-silica or carbon nanotubes, as an effective filler, it can fill the internal voids of the material at the nanoscale, thereby enhancing the rigidity of the cured product and further improving the strength and modulus of the material.

[0025] (2) The present invention uses high molecular weight thermoplastic resin and nano core-shell rubber to synergistically toughen epoxy resin. The high molecular weight thermoplastic resin is dissolved into the epoxy resin at high temperature, and the nano core-shell rubber exists in the form of particles. When the sample is subjected to external force, the thermoplastic resin can effectively absorb part of the destructive energy, produce obvious dimple characteristics and tearing morphology, thereby improving the toughness of the material; the nano core-shell rubber can consume energy through the elastic deformation of the particles and the tearing of the particles, and on the other hand, it can induce the energy consumption process of the matrix, improve the yield deformation capacity of the matrix, and further improve the toughness of the material.

[0026] (3) The high molecular weight thermoplastic resin selected in the present invention also has the function of adjusting the resin rheology, which can meet the hot melt epoxy resin process requirements and will not reduce the modulus of the resin matrix.

[0027] (4) Compared with conventional rubber toughened epoxy, the nano core-shell rubber selected in the present invention can toughen epoxy resin without reducing the modulus and glass transition temperature of the resin due to its unique shell-core structure; in addition, since the nano core-shell rubber and the high molecular weight thermoplastic resin are synergistically toughened, the amount of high molecular weight thermoplastic resin used can be reduced, thereby improving the room temperature viscosity of the resin and making the epoxy resin have good processability. DETAILED DESCRIPTION

[0028] The present invention is further described in detail below with reference to the embodiments.

[0029] Example 1

[0030] Step 1: Mix 30 kg of AFG90H epoxy resin and 15 kg of polyaryletherketone, heat to 120°C and stir for 2 hours, until the polyaryletherketone is completely dissolved in the epoxy resin, to obtain component A;

[0031] Step 2: Take 20 kg of AFG90H epoxy resin and 10 kg of AG80 epoxy resin, add 3 kg of nano-silicon dioxide, 10 kg of nano-core-shell rubber, and 25 kg of 3,3-diaminodiphenyl sulfone respectively, stir evenly, and then pour into a three-roll mill and grind for 10 times to obtain component B;

[0032] Step 3: Mix component A and component B at 60°C and stir evenly to obtain a high-modulus and high-toughness epoxy resin.

[0033] An appropriate amount of newly prepared high modulus and high toughness epoxy resin was taken to prepare a resin casting according to the curing process of keeping warm at 130°C for 1h, keeping warm at 150°C for 1h, and keeping warm at 180°C for 2h. Then the specimens were processed to test their flexural strength, modulus and impact strength. The test results are shown in Table 1.

[0034] Example 2

[0035] Step 1: Mix 30 kg of TDE-85 epoxy resin and 10 kg of poly(arylethersulfone), heat to 120°C and stir for 2 hours, until the poly(arylethersulfone) is completely dissolved in the epoxy resin, to obtain component A;

[0036] Step 2: Take 30 kg of TDE-85 epoxy resin and 20 kg of AG80 epoxy resin, add 5 kg of carbon nanotubes, 3 kg of nano core-shell rubber, and 20 kg of m-phenylenediamine respectively, stir evenly, and then pour into a three-roll mill and grind for 10 times to obtain component B;

[0037] Step 3: Mix component A and component B at 60°C and stir evenly to obtain a high-modulus and high-toughness epoxy resin.

[0038] An appropriate amount of newly prepared high modulus and high toughness epoxy resin was taken to prepare a resin casting according to the curing process of keeping warm at 130°C for 1h, keeping warm at 150°C for 1h, and keeping warm at 180°C for 2h. Then the specimens were processed to test their flexural strength, modulus and impact strength. The test results are shown in Table 1.

[0039] Example 3

[0040] Step 1: Mix 30 kg of AFG90H epoxy resin and 10 kg of polyetherimide, heat to 120 ° C and stir for 2 hours, so that the polyimide is completely dissolved in the epoxy resin to obtain component A;

[0041] Step 2: Take 20 kg of TDE-85 epoxy resin, add 1 kg of nano-silicon dioxide, 5 kg of nano-core-shell rubber, and 20 kg of 3,3-diaminodiphenyl sulfone respectively, stir evenly, and then pour into a three-roll mill and grind for 10 times to obtain component B;

[0042] Step 3: Mix component A and component B at 60°C and stir evenly to obtain a high-modulus and high-toughness epoxy resin.

[0043] An appropriate amount of newly prepared high modulus and high toughness epoxy resin was taken to prepare a resin casting according to the curing process of keeping warm at 130°C for 1h, keeping warm at 150°C for 1h, and keeping warm at 180°C for 2h. Then the specimens were processed to test their flexural strength, modulus and impact strength. The test results are shown in Table 1.

[0044] Comparative Example 1

[0045] Step 1: Mix 40 kg of AFG90H epoxy resin and 10 kg of polyaryletherketone, heat to 120°C and stir for 2 hours, until the polyaryletherketone is completely dissolved in the epoxy resin, to obtain component A;

[0046] Step 2: Take 30 kg of AFG90H epoxy resin, add 30 kg of 3,3-diaminodiphenyl sulfone, stir evenly, and then pour into a three-roll mill and grind for 10 times to obtain component B;

[0047] Step 3: Mix component A and component B at 60° C. and stir them evenly to obtain epoxy resin.

[0048] An appropriate amount of newly prepared epoxy resin was taken and a resin casting was prepared according to the curing process of keeping the temperature at 130°C for 1h, keeping the temperature at 150°C for 1h, and keeping the temperature at 180°C for 2h. Then the specimens were processed to test their flexural strength, modulus and impact strength. The test results are shown in Table 1.

[0049] It can be seen from Table 1 that the bending strength, bending modulus and impact strength of the samples prepared in Examples 1-3 of the present invention are better than those in Comparative Example 1.

[0050] Table 1. Performance comparison between Examples 1-3 and Comparative Example 1

[0051] serial number Bending strength(MPa) Flexural modulus(GPa) <![CDATA[Impact strength (KJ / m 2 )]]> Example 1 149 4.7 32.8 Example 2 148 4.9 30.2 Example 3 148 4.5 31.7 Comparative Example 1 146 4.2 22.4

[0052] The specific embodiments of the present invention disclosed above are intended to help understand the content of the present invention and implement it accordingly. It can be understood by those skilled in the art that various replacements, changes and modifications are possible without departing from the spirit and scope of the present invention. The present invention should not be limited to the contents disclosed in the embodiments of this specification, and the scope of protection of the present invention shall be subject to the scope defined in the claims.

Claims

1. A high modulus and high toughness epoxy resin, characterized in that: The content of each component is as follows: epoxy resin component: 40-80; thermoplastic resin component: 5-25; curing agent component: 10-30; reinforcing agent component: 1-5; toughening agent component: 3-10.

2. The high modulus and high toughness epoxy resin according to claim 1, characterized in that: The epoxy resin component is a high-functionality resin with an epoxy functionality greater than or equal to 3; the thermoplastic resin component is a high-molecular-weight thermoplastic resin; and the curing agent component is an amine curing agent.

3. The high modulus and high toughness epoxy resin according to claim 2, characterized in that: The epoxy resin component is one of AG80, AFG90H, TDE-85 or a mixture of at least two of them.

4. The high modulus and high toughness epoxy resin according to claim 2, characterized in that: The thermoplastic resin component is one or a mixture of at least two of polyarylethersulfone, polyaryletherketone and polyetherimide with an average molecular weight of ≥50,000.

5. The high modulus and high toughness epoxy resin according to claim 1, characterized in that: The curing agent component is one of 3,3-diaminodiphenyl sulfone and meta-phenylenediamine or a mixture of both.

6. The high modulus and high toughness epoxy resin according to claim 1, characterized in that: The reinforcing agent component is one of nano silicon dioxide and carbon nanotubes or a mixture of the two.

7. The high modulus and high toughness epoxy resin according to claim 1, characterized in that: The toughening agent component is nano core-shell rubber with a particle size of 100-300nm.

8. A method for preparing a high modulus and high toughness epoxy resin, characterized in that: The following steps are involved: Take a portion of the epoxy resin component, add the thermoplastic resin component, heat to 100-130°C, mix and stir to dissolve evenly, and obtain component A; Take the remaining epoxy resin component, add the reinforcing agent component, the toughening agent component and the curing agent component respectively, stir evenly, and then pour into a three-roll grinder and grind to obtain component B; The high-modulus and high-toughness epoxy resin is obtained by uniformly mixing component A and component B at a temperature of 60-70°C.

9. The preparation method according to claim 8, characterized in that: The step of pouring the mixture into a three-roll mill and grinding the mixture is performed at least 10 times.