Preparation method of homogeneous and heterogeneous toughened thermosetting resin

Abstract

The invention relates to the technical field of materials, in particular to a preparation method of homogeneous and heterogeneous toughened thermosetting resin. The preparation method comprises the following steps: S1, uniformly dissolving a thermoplastic resin toughening agent in a liquid component of a thermosetting resin matrix in a heating and dissolving manner to obtain a liquid thermoplastic resin toughened thermosetting resin matrix I; and S2, dispersing a thermosetting resin matrix solid component and a thermoplastic resin toughening agent into the liquid thermoplastic resin toughened thermosetting resin matrix I obtained in the step S1 to obtain a completely toughened thermosetting resin system. The toughening modifier is divided into two parts, one part is dissolved in a liquid resin matrix, and the other part is uniformly distributed in the resin matrix in a solid particle form, so that solid-liquid two-phase distribution of the same toughening agent is realized, and the toughening modification of the high-performance resin matrix is realized.

Description

Technical Field

[0001] The invention relates to the technical field of materials, and in particular to a method for preparing a thermosetting resin with homogeneous and heterogeneous toughening. Background Art

[0002] High-performance carbon fiber composite materials have won the favor of engineering designers and are widely used due to their advantages of high strength, high stiffness, light weight, fatigue resistance, corrosion resistance, and unique designability. They have become one of the three main aviation materials along with aluminum alloy and titanium alloy. Since the breakthrough of continuous preparation technology of polyacrylonitrile-based carbon fiber in the 1960s, the strength and modulus of carbon fiber have been continuously improved through years of continuous research and development and application practice in the industry.

[0003] The continuous improvement of the tensile strength and modulus of carbon fiber requires that the performance of the resin system that matches it also needs to be continuously improved, and the toughness of the resin matrix is ​​a research direction that focuses on breakthroughs and improvements. The toughness of advanced resin-based composite materials is closely related to the chemical structure and physical structure of the resin. Many years of research have been conducted at home and abroad on the toughening modification of high-performance resin matrices, and there are many modification methods and approaches, such as synthesizing new long-chain structural monomers, rubber particle modification, thermoplastic resin modification, etc. In summary, these methods mainly improve the toughness of the resin matrix by reducing the crosslinking density of the resin matrix or by preparing microscopic two-phase or multi-phase structures. Reducing the crosslinking density is an effective means to improve toughness, but with the reduction of the crosslinking density, the heat resistance and stiffness of the material system often decrease. Therefore, in order to maintain the high heat resistance of the material system, it is often necessary to design and use a crosslinking agent with a rigid skeleton structure.

[0004] Using high-performance thermoplastic resins with high heat resistance to toughen and modify high-performance resins can maintain the excellent heat resistance and mechanical properties of the system while improving the toughness of the system. In this cured resin system, the thermoplastic resin and the matrix resin often form a two-phase structure. This structure can effectively absorb impact energy and has a significant toughening effect. It is the current mainstream toughening method for thermosetting resin matrices: by introducing thermoplastic resin particles into a highly cross-linked thermosetting resin matrix, crack anchor toughening and mutual transmission network effects are generated to achieve the purpose of efficient toughening. In order to achieve the best particle toughening effect, the toughening agent particles in the resin matrix are required to exist relatively independently, and a clear interface needs to be formed with the resin matrix to conduct and disperse impact stress. However, this will lead to a decrease in the comprehensive mechanical properties of the entire resin system, especially the cohesion of the resin system will decrease significantly, causing a decrease in key mechanical properties such as the compression performance of the composite material system, which will have an adverse effect on the improvement of the comprehensive performance of the composite material. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] The technical problem to be solved by the present invention is the technical problem that the comprehensive mechanical properties of the existing toughened thermosetting resin matrix decrease.

[0007] (II) Technical solution

[0008] In order to solve the above technical problems, the present invention provides a method for preparing a thermosetting resin with homogeneous and heterogeneous toughening, comprising the steps of:

[0009] S1. The thermoplastic resin toughening agent is uniformly dissolved in the liquid component of the thermosetting resin matrix by heating and dissolving to obtain a liquid thermoplastic resin toughened thermosetting resin matrix I;

[0010] S2. Dispersing the solid components of the thermosetting resin matrix and the thermoplastic resin toughening agent in the thermosetting resin matrix I toughened by the liquid thermoplastic resin obtained in step S1 to obtain a completely toughened thermosetting resin system.

[0011] As a preferred solution of the present invention, the solid component of the thermosetting resin matrix is ​​a curing agent or a thermosetting resin monomer.

[0012] As a preferred embodiment of the present invention, the thermoplastic resin toughening agent in step S1 and the thermoplastic resin toughening agent in step S2 are the same thermoplastic resin.

[0013] As a preferred embodiment of the present invention, the solubility of the thermoplastic resin toughening agent in the thermosetting resin matrix is ​​(0.5-20) g.

[0014] As a preferred embodiment of the present invention, the particle size distribution of the thermoplastic resin toughening agent is D50≤50 μm and D90≤100 μm.

[0015] As a preferred embodiment of the present invention, the thermoplastic resin toughening agent is selected from one or more of polyether ketone, polyaryletherketone, polyetheretherketone, polyethersulfone, polyphenylene ether, polyetherimide and polyimide.

[0016] As a preferred embodiment of the present invention, the thermosetting resin matrix includes a bismaleimide resin containing bismaleimide monomers and homologues, diallyl bisphenol A monomers and homologues, or an epoxy resin containing bisphenol A epoxy resin, bisphenol S epoxy resin, bisphenol F epoxy resin, phenolic epoxy resin, amine, imidazole or anhydride curing agent.

[0017] The present invention also provides a thermosetting resin with homogeneous and heterogeneous toughening, which is prepared by the preparation method provided by the present invention.

[0018] (III) Beneficial effects

[0019] The above technical solution of the present invention has the following advantages:

[0020] The present invention divides the toughening modifier into two parts through a homogeneous and heterogeneous toughening method, wherein one part is dissolved in a liquid resin matrix, and the other part is evenly distributed in the resin matrix in the form of solid particles, so as to achieve a solid-liquid two-phase distribution of the same toughening agent, thereby achieving toughening modification of a high-performance resin matrix. The homogeneous and heterogeneous toughening method used in the present invention first ensures that a large amount of particulate toughening agents exist in the resin matrix to exert a good toughening effect of particulate toughening, and secondly, the toughening agent molecules existing in molecular form in the resin matrix can form a good intermolecular force with the toughening agent particles existing alone in the form of particles, thereby enhancing the interface strength between the toughening agent particles and the resin matrix, and ensuring the good integrity of the resin matrix, thereby being able to improve the comprehensive mechanical properties of the entire resin system, thereby achieving a synergistic improvement in high toughness and high mechanical properties of the composite material. DETAILED DESCRIPTION

[0021] The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0022] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods; the reagents, materials, etc. used in the following examples, unless otherwise specified, can be obtained from commercial channels.

[0023] A method for preparing a thermosetting resin with homogeneous and heterogeneous toughening, comprising the steps of:

[0024] S1. The thermoplastic resin particles are uniformly dissolved in the liquid component of the thermosetting resin matrix by heating and dissolving to obtain a liquid thermoplastic resin toughened thermosetting resin matrix I;

[0025] S2. Dispersing the solid components of the thermosetting resin matrix and the thermoplastic resin toughening agent in the thermosetting resin matrix I toughened by the liquid thermoplastic resin obtained in step S1 to obtain a completely toughened thermosetting resin system.

[0026] As a preferred solution of the present invention, the solid component of the thermosetting resin matrix is ​​a curing agent or a thermosetting resin monomer.

[0027] As a preferred embodiment of the present invention, the thermoplastic resin toughening agent in S1 and the thermoplastic resin toughening agent in S2 are the same thermoplastic resin.

[0028] As a preferred embodiment of the present invention, the solubility of the thermoplastic resin toughening agent in the thermosetting resin matrix is ​​(0.5-20) g.

[0029] As a preferred embodiment of the present invention, the particle size distribution of the thermoplastic resin toughening agent is D50≤50 μm and D90≤100 μm.

[0030] As a preferred embodiment of the present invention, the thermoplastic resin toughening agent is selected from one or more of polyether ketone, polyaryletherketone, polyetheretherketone, polyethersulfone, polyphenylene ether, polyetherimide and polyimide.

[0031] As a preferred embodiment of the present invention, the thermosetting resin matrix includes a bismaleimide resin containing bismaleimide monomers and homologues, diallyl bisphenol A monomers and homologues, or an epoxy resin containing bisphenol A epoxy resin, bisphenol S epoxy resin, bisphenol F epoxy resin, phenolic epoxy resin, amine, imidazole or anhydride curing agent.

[0032] The high-performance resin system described in the above implementation steps includes, in addition to the thermoplastic toughening agent, liquid resins of different components (such as bismaleimide resin monomer), other process additives, curing agents, etc. Other additives and curing agents are prepared by hot melting, mutual dissolution, mixing, grinding, etc. according to material properties or other process control requirements. This is a conventional traditional technology and no special requirements are made in the present invention.

[0033] The present invention relates to the field of material technology, and in particular to a homogeneous heterogeneous toughening method for high-performance thermosetting resins used in fiber-reinforced composite materials. Fiber-reinforced resin-based composite materials used in the aerospace field are mainly high-performance epoxy resins or high-performance bismaleimide resins. In order to meet the requirements of equipment for high toughness, it is usually necessary to toughen and modify the resin matrix.

[0034] The present invention divides the toughening modifier into two parts through a homogeneous and heterogeneous toughening method, wherein one part is dissolved in a liquid resin matrix, and the other part is evenly distributed in the resin matrix in the form of solid particles, so as to achieve a solid-liquid two-phase distribution of the same toughening agent, thereby achieving toughening modification of a high-performance resin matrix. The homogeneous and heterogeneous toughening method used in the present invention first ensures that a large amount of particulate toughening agents exist in the resin matrix to exert a good toughening effect of particulate toughening, and secondly, the toughening agent molecules existing in molecular form in the resin matrix can form a good intermolecular force with the toughening agent particles existing alone in the form of particles, thereby enhancing the interface strength between the toughening agent particles and the resin matrix, and ensuring the good integrity of the resin matrix, thereby being able to improve the comprehensive mechanical properties of the entire resin system, thereby achieving a synergistic improvement in high toughness and high mechanical properties of the composite material.

[0035] Example 1

[0036] This embodiment provides a method for preparing a thermosetting resin with isotropic toughening, using a thermoplastic polyimide resin to toughen and modify a bismaleimide resin, comprising the steps of:

[0037] S1. Thermoplastic polyimide resin particles are dispersed in the liquid copolymer monomer diallyl bisphenol A of bismaleimide resin by heating and dissolving using a planetary disperser. After the dissolution is completed and the temperature is lowered, a liquid copolymer component toughened by a liquid polyimide resin is obtained.

[0038] S2. Add thermosetting resin monomer (bismaleimide resin monomer) to the obtained liquid copolymer component toughened by liquid polyimide resin, and achieve shear dispersion and mixing through a planetary disperser. After uniform mixing, the same thermoplastic polyimide resin particles are subjected to strong shear dispersion and uniform mixing through a three-roll grinder to obtain a prepared high-toughness bismaleimide resin system, namely the present invention.

[0039] Comparative analysis shows that the tensile strength of the resin casting body prepared by the homogeneous heterogeneous toughening method after curing reaches 121MPa, and the unnotched impact strength reaches 42kJ / m 2 The domestic T800 carbon fiber reinforced resin matrix composite material was prepared by hot melt method, and the post-impact compression strength reached 358MPa, the interlaminar shear strength reached 123MPa, and the 0° compression strength reached 1962MPa.

[0040] The solubility of the thermoplastic resin particles in diallyl bisphenol A in this example is 6 g, and the D50 and D90 of the particles are 17 μm and 79 μm respectively.

[0041] Example 2

[0042] This embodiment provides a method for preparing a thermosetting resin with homogeneous and heterogeneous toughening, using a thermoplastic polyethersulfone resin to toughen and modify an epoxy resin, comprising the steps of:

[0043] S1. Premix bisphenol A epoxy resin, aromatic high temperature resistant epoxy resin and epoxy resin diluent into a uniform transparent liquid mixture by heating and mixing, and then disperse thermoplastic polyethersulfone resin particles in the above mixed liquid resin by heating and dissolving using a planetary disperser. After dissolution is completed and the temperature is lowered, a liquid polyethersulfone resin toughened epoxy resin matrix is ​​obtained.

[0044] S2. Add diaminodiphenyl sulfone curing agent and thermoplastic polyethersulfone resin particle monomer to the obtained liquid polyethersulfone resin toughened epoxy resin matrix, first pre-mix by a planetary disperser and then disperse and mix evenly by strong shearing on a three-roll grinder to obtain a prepared high-toughness epoxy resin system, namely the present invention.

[0045] Comparative analysis shows that the tensile strength of the resin casting body after curing of the modified epoxy resin system prepared by the homogeneous heterogeneous toughening method reaches 119MPa, and the unnotched impact strength reaches 64kJ / m 2The domestic T800 carbon fiber reinforced resin matrix composite material was prepared by hot melt method, and the post-impact compression strength reached 361MPa, the interlaminar shear strength reached 119MPa, and the 0° compression strength reached 1897MPa.

[0046] The solubility of the thermoplastic polyethersulfone resin particles in the bisphenol A epoxy resin in this embodiment is 17 g, and the D50 of the particles is 11 μm and the D90 is 62 μm.

[0047] It should be clear that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. For the embodiments of the method, the relevant parts can refer to the partial description of the device embodiment (adopted according to the writing situation). The present invention is not limited to the specific steps described above. In addition, for the sake of brevity, the detailed description of the known method technology is omitted here.

[0048] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a thermosetting resin with homogeneous and heterogeneous toughening, characterized in that: Includes steps: S1. The thermoplastic resin toughening agent is uniformly dissolved in the liquid component of the thermosetting resin matrix by heating and dissolving to obtain a liquid thermoplastic resin toughened thermosetting resin matrix I; S2. Dispersing the solid components of the thermosetting resin matrix and the thermoplastic resin toughening agent in the thermosetting resin matrix I toughened by the liquid thermoplastic resin obtained in step S1 to obtain a completely toughened thermosetting resin system.

2. The preparation method according to claim 1, characterized in that In step S2, the solid component of the thermosetting resin matrix is ​​a curing agent or a thermosetting resin monomer.

3. The preparation method according to claim 1, characterized in that: The thermoplastic resin toughening agent in step S1 and the thermoplastic resin toughening agent in step S2 are the same thermoplastic resin.

4. The preparation method according to claim 1 or 3, characterized in that: The solubility of the thermoplastic resin toughening agent in the thermosetting resin matrix is ​​(0.5-20) g.

5. The preparation method according to claim 1 or 4, characterized in that: The particle size distribution of the thermoplastic resin toughening agent is D50≤50μm and D90≤100μm.

6. The preparation method according to claim 1 or 5, characterized in that: The thermoplastic resin toughening agent is selected from one or more of polyether ketone, polyaryletherketone, polyetheretherketone, polyethersulfone, polyphenylene ether, polyetherimide and polyimide.

7. The preparation method according to claim 1, characterized in that: The thermosetting resin matrix includes bismaleimide resin containing bismaleimide monomers and homologues, diallyl bisphenol A monomers and homologues, or epoxy resin containing bisphenol A epoxy resin, bisphenol S epoxy resin, bisphenol F epoxy resin, novolac epoxy resin, amine, imidazole or anhydride curing agent.

8. A thermosetting resin with homogeneous and heterogeneous toughening, prepared by the preparation method according to any one of claims 1 to 6.