A low-forming temperature thermoset composite material for aerospace and a method for preparing the same

Abstract

The application discloses a low-forming-temperature thermosetting composite material for aviation and a preparation method thereof, and belongs to the technical field of thermosetting materials for aviation. The thermosetting composite material comprises 10-20 parts of an amine curing agent, 5-15 parts of a cyanate ester monomer, 0.3-2.0 parts of a divalent metal salt, 80-100 parts of a thermosetting resin and 10-20 parts of a toughening agent. The application innovatively prepares a ternary composite curing agent system capable of significantly improving a curing forming rate by using the amine curing agent, the cyanate ester monomer and the divalent metal salt. The amino group and the phenolic hydroxyl group in the benzoxazine resin can accelerate the curing rate of the epoxy resin and the bismaleimide resin, so that the toughening agent has the effects of improving toughness and self-catalysis. The reinforced thermosetting composite material prepared by the application has low forming temperature and excellent use performance, and can be used for manufacturing high-temperature-resistant aviation resin matrix composite material parts.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of thermosetting materials for aviation, and particularly relates to a thermosetting composite material with low forming temperature for aviation and a preparation method thereof. BACKGROUND

[0002] Carbon fiber reinforced resin matrix composite material is one of the key materials widely used in the aviation field at present and in the future. At present, the high-temperature resistant carbon fiber resin matrix composite material for aviation mainly includes high-temperature curing epoxy composite material (forming temperature: 180±5℃) and bismaleimide and cyanate ester composite material (forming temperature: 200±5℃). Reducing the forming and curing temperature of the composite material is of great significance for reducing the manufacturing cost of the composite material, shortening the manufacturing cycle of the composite material, and reducing the deformation and internal quality risk caused by temperature rise and fall. However, reducing the forming temperature usually means reducing the use temperature of the material, and also leads to the reduction of the mechanical properties of the material and the shortening of the storage period.

[0003] The glass transition temperature of the traditional 180℃ curing high-temperature epoxy-based composite material is usually about 210~230℃. In view of this problem, some research teams have tried to add latent imidazole curing agents to the epoxy composite material system, and the material forming and curing temperature is reduced to 100℃, and the glass transition temperature (a key indicator of temperature resistance performance) is about 140~150℃. However, this method is only suitable for medium-temperature curing epoxy systems. In addition, it is reported that by adding a self-catalyzing component to the high-temperature epoxy resin, the forming temperature of the epoxy composite material is reduced, but the curing temperature is also reduced. Compared with epoxy-based composite materials, there are fewer reports on reducing the bismaleimide and cyanate ester composite materials to below 200℃. It is reported that by adding organic oxime substances to bismaleimide resin, the forming temperature of the composite material can be reduced to about 180℃, but the glass transition temperature is also reduced (260℃ when cured below 200℃).

[0004] For example, the existing Chinese patent CN116606529B discloses a low-temperature curing epoxy resin and a preparation method, a prepreg, a composite material and an application. The low-temperature curing epoxy resin comprises the following components in parts by weight: 50~80 parts of epoxy resin, 10~20 parts of curing agent, 2~5 parts of accelerator, 10~20 parts of toughening agent, and 0.1~1 part of corrosion inhibitor. The epoxy resin comprises 10~20 parts by weight of low-viscosity liquid hydantoin-type epoxy resin, 10~25 parts by weight of phenolic epoxy resin, 10~20 parts by weight of solid bisphenol A-type epoxy resin, and 10~20 parts by weight of low-viscosity bisphenol F-type epoxy resin. The accelerator is a latent imidazole type accelerator.

[0005] The existing Chinese patent CN109265922B discloses a high-toughness self-catalytic epoxy resin and a preparation method, which is composed of 1-15 parts by mass of hyperbranched polysiloxane containing multiple active functional groups, 60-90 parts of bisphenol A type epoxy resin and 50-60 parts of acid anhydride curing agent.

[0006] The existing Chinese patent CN111793193A discloses a solvent-free type temperature-resistant 180℃ ultra-low viscosity epoxy resin matrix and a preparation method thereof. The epoxy resin matrix is composed of difunctional epoxy resin, multifunctional epoxy resin and liquid curing system. The preparation method of the epoxy resin matrix comprises: fully mixing and uniformly mixing each component under high-speed stirring, and vacuum degassing bubbles to obtain the epoxy resin matrix. The glass transition temperature (Tg) of the matrix after medium temperature (150℃) curing is greater than 180℃.

[0007] In summary, the existing improved scheme still cannot completely solve the problem of reducing the use performance caused by reducing the molding temperature, and does not have the problem of universality. Therefore, the best solution is to reduce the curing temperature of the material while not affecting the use temperature and mechanical properties of the material, and can be popularized to multiple types of materials. SUMMARY

[0008] The purpose of the present application is to provide a low-molding-temperature thermosetting composite material for aviation and a preparation method thereof, which aims to solve the above problems.

[0009] The present application is mainly realized by the following technical solutions:

[0010] A low-molding-temperature thermosetting composite material for aviation, which comprises the following components in parts by weight:

[0011] Amine curing agent: 10-20 parts;

[0012] Cyanate monomer: 5-15 parts;

[0013] Divalent metal salt: 0.3-2.0 parts;

[0014] Thermosetting resin: 80-100 parts;

[0015] Toughening agent: 10-20 parts;

[0016] The toughening agent includes any multiple of thermoplastic polyarylether resin, benzoxazine resin and diallyl bisphenol A.

[0017] In order to better realize the present application, further, the toughening agent includes thermoplastic phenolphthalein type polyarylether ketone resin, bisphenol type benzoxazine resin and diallyl bisphenol A, and the mass ratio is 100:20-40:0-10.

[0018] In order to better realize the present application, further, the thermosetting resin comprises any one or more of bisphenol A type epoxy resin, diphenyl methane type bismaleimide resin, and phenolic type epoxy resin.

[0019] In order to better realize the present application, further, the thermosetting resin comprises bisphenol A type epoxy resin and bismaleimide resin, or the thermosetting resin comprises diphenyl methane type bismaleimide resin and E54 epoxy resin.

[0020] In order to better realize the present application, further, the amine curing agent is aromatic amine curing agent; and the cyanate ester monomer is bisphenol type cyanate ester monomer.

[0021] In order to better realize the present application, further, the amine curing agent is 3,3'-diamino diphenyl sulfone, and the cyanate ester monomer is bisphenol A cyanate ester monomer.

[0022] In order to better realize the present application, further, the divalent metal salt is divalent metal halide.

[0023] In order to better realize the present application, further, the divalent metal salt is ZnCl2 or CoCl2.

[0024] The present application is mainly realized by the following technical solutions:

[0025] A preparation method of a low-forming-temperature thermosetting composite material for aviation, comprising the following steps:

[0026] Step S1: mixing the amine curing agent and the cyanate ester monomer in a reaction kettle at a temperature of 100-120℃, and stirring for 20-40min;

[0027] Step S2: reducing the temperature of the reaction kettle to 70-90℃, then adding the divalent metal salt, and stirring for 10-20min to prepare a composite curing agent;

[0028] Step S3: mixing the thermosetting resin and the toughening agent in the reaction kettle at a temperature of 110-130℃, and stirring for 30-60min;

[0029] Step S4: reducing the temperature of the reaction kettle to 50-70℃, adding the composite curing agent prepared in step S2, and mixing uniformly to prepare a reinforced thermosetting composite material.

[0030] The present application has the following advantages:

[0031] (1) The curing system in the resin formula is innovatively designed, and a composite curing agent component is prepared based on an amine curing agent, a cyanate ester monomer and a divalent metal salt, so that the curing molding activity at a specific temperature is improved. Specifically, the synergistic curing effect of diamine, cyanate ester monomer and divalent metal salt on epoxy and bismaleimide composites is utilized, and a ternary composite curing agent system capable of significantly improving the curing molding rate is innovatively prepared.

[0032] (2) The toughening system is also improved, so that the toughening agent has the functions of toughening and accelerating curing molding. Specifically, the amino and phenolic hydroxyl groups in the benzoxazine resin can accelerate the curing rate of epoxy and bismaleimide resins, and the toughening formula is innovatively added to the resin toughening formula, so that the toughening component used in the scheme has the effects of improving toughness and self-catalysis.

[0033] (3) The improved curing system and toughening system can be applied to improve various high-temperature epoxy, bismaleimide and cyanate ester thermosetting resin-based composites. The prepared reinforced thermosetting composite material has low molding temperature and excellent use performance, and can be used to manufacture high-temperature resistant aviation resin-based composite parts. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 The glass transition temperature test curve of the aviation carbon fiber reinforced thermosetting composite material in Example 1. DETAILED DESCRIPTION

[0035] Example 1:

[0036] A preparation method of a low-molding-temperature thermosetting composite material for aviation, comprising the following steps:

[0037] As shown in Table 1, 20 parts of 3,3'-diaminodiphenyl sulfone and 10 parts of bisphenol A cyanate ester monomer were weighed, and stirring was carried out at a temperature of 115℃ for 25 min. When the temperature decreased to about 75℃, 0.4 parts of ZnCl2 catalyst was added and stirred for 15 min. After uniform, the composite curing agent was obtained, and was placed in a low temperature environment.

[0038] Then the temperature of the reaction kettle was raised to 125℃, 80 parts of E54 epoxy resin, 20 parts of phenolic epoxy resin and 12 parts of toughening agent (the toughening agent was selected from thermoplastic phenolphthalein polyarylether ketone resin and bisphenol type benzoxazine resin, and the ratio was 3:1) were added, and after stirring for 45 min, the temperature was lowered to 60℃, and the above prepared composite curing agent was added. After stirring uniformly, the final resin was obtained.

[0039] Then the above resin was cured at 160℃ for 3h to obtain a cured product. As shown in Figure 1 , the glass transition temperature of the cured product was measured to be 228.5℃.

[0040] Example 2:

[0041] A method for preparing a low-forming-temperature thermosetting composite material for aviation, comprising the following steps:

[0042] As shown in Table 1, 20 parts of 3,3'-diaminodiphenyl sulfone and 10 parts of bisphenol A cyanate monomer were weighed, and stirring was performed at 115°C for 25 min. When the temperature decreased to about 70°C, 0.5 parts of CoCl2 catalyst was added and stirred for 15 min. After uniform, the composite curing agent was obtained, and was placed in a low temperature environment.

[0043] Then the temperature of the reaction kettle was raised to 125°C, 85 parts of E54 epoxy resin, 15 parts of phenolic epoxy resin and 12 parts of toughening agent (the toughening agent was selected from thermoplastic phenolphthalein type polyaryletherketone resin and bisphenol type benzoxazine resin, and the ratio was 3:1) were added, and after stirring for 50 min, it was cooled to 60°C, and the above prepared composite curing agent was added. After uniform stirring, the final resin was obtained.

[0044] Then the above resin was cured at 160°C for 3h to obtain a cured product. The glass transition temperature of the cured product was measured to be 230.1°C.

[0045] Example 3:

[0046] A method for preparing a low-forming-temperature thermosetting composite material for aviation, comprising the following steps:

[0047] As shown in Table 1, 10 parts of 3,3'-diaminodiphenyl sulfone and 10 parts of bisphenol A cyanate monomer were weighed, and stirring was performed at 120°C for 30 min. When the temperature decreased to about 75°C, 0.4 parts of ZnCl2 catalyst was added and stirred for 10 min. After uniform, the composite curing agent was obtained, and was placed in a low temperature environment.

[0048] Then the temperature of the reaction kettle was raised to 120°C, 100 parts of diphenylmethane type bismaleimide resin, 8 parts of E54 resin and 13 parts of toughening agent (the toughening agent was selected from thermoplastic phenolphthalein type polyaryletherketone resin and bisphenol type benzoxazine resin, and the ratio was 2:1) were added, and after stirring for 60 min, it was cooled to 60°C, and the above prepared composite curing agent was added. After uniform stirring, the final resin was obtained.

[0049] Then the above resin was cured at 180°C for 5h to obtain a cured product. The glass transition temperature of the cured product was measured to be 255.3°C.

[0050] Example 4:

[0051] A method for preparing a low-forming-temperature thermosetting composite material for aviation, comprising the following steps:

[0052] As shown in Table 1, 10 parts of 3,3'-diaminodiphenyl sulfone and 10 parts of bisphenol A cyanate monomer were weighed, and stirred at 120°C for 30 min. When the temperature decreased to about 75°C, 0.3 parts of ZnCl2 catalyst was added and stirred for 10 min. After uniform, the composite curing agent was obtained and placed in a low temperature environment.

[0053] Then the temperature of the reactor was raised to 115°C, 100 parts of diphenylmethane type bismaleimide resin, 7 parts of E54 resin and 16 parts of toughening agent (the toughening agent was a mixture of thermoplastic phenolphthalein type polyaryletherketone resin, bisphenol type benzoxazine resin and diallyl bisphenol A, with a ratio of 100:28:10) were added, and stirred for 60 min. Then the temperature was reduced to 60°C, and the above prepared composite curing agent was added. After uniform stirring, the final resin was obtained.

[0054] Then the above resin was cured at 180°C for 5h to obtain a cured product. The glass transition temperature of the cured product was measured to be 253.4°C.

[0055] Example 5:

[0056] A method for preparing an aerospace low-forming-temperature thermosetting composite material, comprising the following steps:

[0057] As shown in Table 1, 10 parts of 3,3'-diaminodiphenyl sulfone and 10 parts of bisphenol A cyanate monomer were weighed, and stirred at 120°C for 30 min. When the temperature decreased to about 75°C, 0.3 parts of ZnCl2 catalyst was added and stirred for 10 min. After uniform, the composite curing agent was obtained and placed in a low temperature environment.

[0058] Then the temperature of the reactor was raised to 115°C, 100 parts of diphenylmethane type bismaleimide resin, 7 parts of E54 resin and 16 parts of toughening agent (the toughening agent was a mixture of thermoplastic phenolphthalein type polyaryletherketone resin, bisphenol type benzoxazine resin and diallyl bisphenol A, with a ratio of 100:28:10) were added, and stirred for 60 min. Then the temperature was reduced to 60°C, and the above prepared composite curing agent was added. After uniform stirring, the final resin was obtained.

[0059] Then the above resin was cured at 180°C for 5h to obtain a cured product. The glass transition temperature of the cured product was measured to be 253.4°C.

[0060] Table 1

[0061]

[0062] The above is only the preferred embodiment of the present application, and does not limit the present application in any form. Any simple modification or equivalent change of the above embodiment according to the technical essence of the present application falls within the protection scope of the present application.

Claims

1. A low-forming temperature thermoset composite material for aerospace applications, characterized in that, By weight parts, including the following components: Amine curing agent: 10~20 parts; Cyanate monomer: 5~15 parts; Divalent metal salt: 0.3~2.0 parts; Thermosetting resin: 80~100 parts; Toughening agent: 10~20 parts; The toughening agent includes any of thermoplastic polyaryletherketone resin, benzoxazine resin and diallyl bisphenol A; The amine curing agent is 3,3'-diamino diphenyl sulfone, the cyanate monomer is bisphenol A cyanate monomer; the divalent metal salt is ZnCl2 or CoCl2; The preparation method of the thermosetting composite material includes the following steps: Step S1: the amine curing agent and the cyanate monomer are mixed in the reaction kettle at a temperature of 100-120℃, and stirred for 20-40min; Step S2: the temperature of the reaction kettle is lowered to 70-90℃, then the divalent metal salt is added, and stirred for 10-20min to prepare a composite curing agent; Step S3: the thermosetting resin and the toughening agent are mixed in the reaction kettle at a temperature of 110-130℃, and stirred for 30-60min; Step S4: the temperature of the reaction kettle is lowered to 50-70℃; the composite curing agent prepared in step S2 is added; after uniform mixing, the reinforced thermosetting composite material is prepared.

2. A low forming temperature thermoset composite material for aerospace applications according to claim 1, characterized in that, The toughening agent includes thermoplastic phenolphthalein type polyaryletherketone resin, bisphenol type benzoxazine resin and diallyl bisphenol A, and the mass ratio is 100:20~40:0~10.

3. A low forming temperature thermoset composite material for aerospace applications according to claim 1, characterized in that, The thermosetting resin includes any one or more of bisphenol A type epoxy resin, diphenylmethane type bismaleimide resin and phenolic type epoxy resin.

4. A low forming temperature thermoset composite material for aerospace applications according to claim 3, characterized in that, The thermosetting resin includes bisphenol A type epoxy resin and bismaleimide resin, or the thermosetting resin includes diphenylmethane type bismaleimide resin and E54 epoxy resin.

5. A process for the preparation of a low forming temperature thermoset composite material for aerospace applications, for the preparation of a low forming temperature thermoset composite material for aerospace applications according to any one of claims 1 to 4, characterized in that, Including the following steps: Step S1: the amine curing agent and the cyanate monomer are mixed in the reaction kettle at a temperature of 100-120℃, and stirred for 20-40min; Step S2: the temperature of the reaction kettle is lowered to 70-90℃, then the divalent metal salt is added, and stirred for 10-20min to prepare a composite curing agent; Step S3: the thermosetting resin and the toughening agent are mixed in the reaction kettle at a temperature of 110-130℃, and stirred for 30-60min; Step S4: the temperature of the reaction kettle is lowered to 50-70℃; the composite curing agent prepared in step S2 is added; after uniform mixing, the reinforced thermosetting composite material is prepared.

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