CN110872374B

CN110872374B - Intrinsic structure damping integrated material with reversible shape memory property and preparation method thereof

Info

Publication number: CN110872374B
Application number: CN201911193739.8A
Authority: CN
Inventors: 邹华维; 周勣; 陈洋; 衡正光; 梁梅
Original assignee: Sichuan University
Current assignee: Sichuan University
Priority date: 2019-11-28
Filing date: 2019-11-28
Publication date: 2022-04-19
Anticipated expiration: 2039-11-28
Also published as: CN110872374A

Abstract

The invention provides an intrinsic structure damping integrated material with shape memory property. Compared with the common cured epoxy resin E51-DMM, the cured epoxy resin PEE-DMM and the PDE-DMM prepared by the method of 'hard filling' have remarkably widened damping temperature range, excellent mechanical properties (particularly bending modulus) and reversible shape memory characteristics, are excellent intrinsic structure damping integrated materials, and have wide application prospects in the fields of aerospace and the like.

Description

Intrinsic structure damping integrated material with reversible shape memory property and preparation method thereof

Technical Field

The invention belongs to the field of high polymer materials, and particularly relates to an intrinsic structure damping integrated material with reversible shape memory property and a preparation method thereof.

Background

With the development of aerospace equipment towards light weight, high speed, automation and multiple functions, the requirements on the composite material and the composite material matrix in special equipment are higher and higher. The application environments of the application fields are severe, and the high-frequency vibration and noise can deteriorate the dynamic environment of precise electronic instruments and meters on aerospace products, reduce the precision and reliability of navigation and control systems, and bring great challenges to the working stability of precise instruments. Damping materials have attracted attention because they can convert mechanical vibrational energy into thermal energy for dissipation, effectively controlling vibration and noise. However, most damping materials have limited application temperature, and the mechanical properties of the damping materials are sharply reduced at a slightly high temperature, so that the requirements of structural materials on rigidity and strength cannot be met.

Epoxy resin is used as the most common thermosetting resin, has good mechanical property, and can not be decomposed or melted along with the rise of temperature, so that the epoxy resin is widely applied to composite materials such as aerospace equipment. However, the damping performance of the traditional bisphenol A type epoxy resin (DGEBA) is relatively poor, and the effective damping temperature range (Tan delta >0.3) is only 20 ℃ around the glass transition temperature (Tg), which means that the damping performance of the epoxy resin is poor in a wide range of use temperatures.

In modern diversified resin application environments, more and more situations require that the material has excellent damping and shock absorption characteristics and excellent mechanical properties at the same time under the use temperature, so that the preparation of the structural damping integrated composite material becomes a research hotspot in recent decades.

From the last 90 s, scholars at home and abroad put forward a plurality of technical schemes around the preparation of structural damping integrated composite materials, and materials with two or more Tg peaks are prepared by a method of blending rubber, plastic and resin in the early stage so as to widen the damping temperature range of the materials. In recent years, researchers try to prepare a novel structural damping integrated material by adopting a microstructure design, such as preparing a submicron powder frame structure based on epoxy by adopting a laser photoetching technology, or intercalating viscoelastic macromolecules into high-rigidity montmorillonite layers to form a rigid/viscoelastic alternative layered structure and introducing a structural resin system, or realizing structural damping integration of the material by spontaneously forming a specific microstructure in epoxy resin through block copolymers. The German research group introduces a pendant chain into an elastomer by a controllable free polymerization method to obtain a damping elastomer with a wide damping peak, and the Japanese research group obtains a micro-phase-separated elastomer by introducing a hydrocarbon chain pendant chain and also widens the effective damping temperature range of the material. However, the above methods all achieve the widening of the effective damping temperature range by introducing additional structural variables into the matrix material, and the preparation method is complex and has high cost. And the methods cannot simultaneously improve the mechanical modulus of the material and widen the damping temperature range of the material. At present, no intrinsic structure damping integrated material with both mechanical property and damping property remarkably improved is reported.

In addition, the shape memory material as a novel intelligent high polymer material can respond to the triggering of external stimulation such as heat, chemistry, machinery, light, magnetism or electricity and the like to perform shape remodeling, so that the technical parameters of the shape memory material are changed, and the shape memory material has wide application in the fields of aerospace, biomedicine, power electronics, packaging, intelligent control systems and the like. However, most of the existing epoxy resins have high glass transition temperature (Tg), have poor remolding property, and even if the epoxy resins are heated to the vicinity of the Tg, the shapes of the epoxy resins are difficult to be freely remolded, which limits the application of the epoxy resins to a certain extent. Therefore, the preparation of the intrinsic structure damping integrated material which has high damping performance, excellent mechanical property and reversible plastic shape memory performance has very important significance.

Disclosure of Invention

The invention aims to provide an intrinsic structure damping integrated material which not only has high damping performance, but also has excellent mechanical property and reversible plastic shape memory performance.

The invention provides a structural damping integrated material, which is obtained by carrying out a curing reaction on epoxy resin and a curing agent, wherein the structure of the epoxy resin is shown as a formula 3 or a formula 4:

the epoxy value of the epoxy resin shown in the formula 3 is 0.25-0.40, and the epoxy value of the epoxy resin shown in the formula 4 is 0.15-0.30.

Further, the epoxy value of the epoxy resin represented by formula 3 is 0.32, and the epoxy value of the epoxy resin represented by formula 4 is 0.23;

and/or the curing agent is an aromatic amine curing agent, preferably DDM;

and/or the molar ratio of the epoxy resin to the curing agent is 1: (0.8 to 1.2), preferably 1: 1.

further, the epoxy resin is prepared from bisphenol compounds and epichlorohydrin, wherein the structure of the bisphenol compounds is shown in formula 1 or formula 2:

preferably, the raw materials for preparing the epoxy resin also comprise a catalyst, and preferably, the catalyst is benzyltrimethylammonium chloride;

the molar ratio of the bisphenol compound to the epichlorohydrin to the catalyst is 10: (300-500): (0.3-1), preferably 10:400: 0.5.

the invention provides a method for preparing the damping integrated material with the structure, which comprises the following steps:

(1) uniformly mixing bisphenol compounds and epoxy chloropropane, and reacting to obtain the epoxy resin; the structure of the bisphenol compound is shown in formula 1 or formula 2:

(2) and (2) uniformly mixing the epoxy resin obtained in the step (1) with a curing agent, and curing to obtain the epoxy resin.

Further, in the step (1), the reaction is carried out under the action of a catalyst, preferably, the catalyst is benzyltrimethylammonium chloride;

the reaction temperature is 80-100 ℃ and the reaction time is 20-30 hours, preferably, the reaction temperature is 90 ℃ and the reaction time is 24 hours;

the epoxy value of the epoxy resin represented by formula 3 is 0.32, and the epoxy value of the epoxy resin represented by formula 4 is 0.23.

Further, in the step (2), the curing conditions are as follows: curing was carried out at 135 ℃ for 3 hours and then at 180 ℃ for 3 hours.

The present invention also provides bisphenol compounds represented by formula 2:

the invention also provides an epoxy resin shown in formula 3 or formula 4:

wherein the epoxy value of the epoxy resin shown in the formula 3 is 0.25-0.40, preferably 0.32;

the epoxy value of the epoxy resin represented by formula 4 is 0.15 to 0.30, preferably 0.23.

The invention also provides a preparation method of the bisphenol compound shown in the formula 2, which comprises the following steps: mixing 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 4-hydroxyacetophenone and phenol uniformly, and reacting to obtain the final product;

preferably, the reaction is carried out under the action of a catalyst, namely p-hydroxybenzene sulfonic acid;

the reaction temperature is 110-150 ℃, and the reaction time is 20-30 hours;

the reaction is carried out under the protection of inert gas;

the molar ratio of the 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to the 4-hydroxyacetophenone to the phenol (0.5-1.5): (0.5-1.5): 100, preferably 1: 1: 100.

the invention also provides a preparation method of the epoxy resin, which comprises the following steps: uniformly mixing the bisphenol compound shown in the formula 1 or the bisphenol compound shown in the formula 2 with epoxy chloropropane, and reacting to obtain the bisphenol compound;

preferably, the reaction is carried out under the action of a catalyst, and the catalyst is benzyltrimethylammonium chloride;

the bisphenol compound shown in the formula 1 or the bisphenol compound shown in the formula 2, epichlorohydrin and a catalyst are in a molar ratio of 10: (300-500): (0.3-1), preferably 10:400: 0.5;

the reaction temperature is 80-100 ℃ and the reaction time is 20-30 hours, and preferably the reaction temperature is 90 ℃ and the reaction time is 24 hours.

The invention prepares two novel cured epoxy resins PEE-DMM and PDE-DMM by a phase transfer catalyst method. In the invention, a rigid structure is introduced into a molecular chain structure of the thermosetting resin as a suspension chain, the rigid structure plays a role of supporting in a microstructure of a material, and a large number of rigid suspension chains play a similar 'filling dilution' effect on a cross-linked network, which is called as 'hard filling'. The 'hard filling' method does not need to introduce extra substances to change the structure of the epoxy resin, has simple process and low cost, and is suitable for industrial expanded production.

Experimental results show that compared with the common epoxy resin E51-DMM, the cured epoxy resin PEE-DMM and the PDE-DMM prepared by the method of 'hard filling' have remarkably widened damping temperature range, excellent mechanical properties (particularly bending modulus) and reversible shape memory characteristics, are excellent intrinsic structure damping integrated materials, and have wide application prospects in the fields of aerospace and the like.

Obviously, many modifications, substitutions, and variations are possible in light of the above teachings of the invention, without departing from the basic technical spirit of the invention, as defined by the following claims.

The present invention will be described in further detail with reference to the following examples. This should not be understood as limiting the scope of the above-described subject matter of the present invention to the following examples. All the technologies realized based on the above contents of the present invention belong to the scope of the present invention.

Drawings

FIG. 1 is a schematic diagram of the preparation of E51-DMM, PEE-DMM and PDE-DMM according to the present invention.

FIG. 2. Synthesis procedure for PEE.

FIG. 3 Synthesis steps of BDP and PDE.

FIG. 4 is an infrared spectrum of PDE, BPD, PEE and BPP.

FIG. 5 of BPD and BPP¹H nuclear magnetic resonance spectrogram.

FIG. 6 dynamic mechanical analysis of three epoxy resins E51-DMM, PEE-DMM, PDE-DMM: a) storage moduli of the three epoxy resins, b) loss factor versus temperature curves of the three epoxy resins.

FIG. 7 shows the PEE-DMM bent into different shapes after being heated to 130 ℃.

FIG. 8 shows three epoxy resins E51-DMM, PEE-DMM, PDE-DMM a) first relaxation peak broken lines with temperature change, b) relaxation time curves at different temperatures.

FIG. 9 three epoxy resins E51-DMM, PEE-DMM, PDE-DMM a) dielectric loss versus temperature curves, b) fitting a Havriliak-Negami equation.

FIG. 10 is a logic model for modeling three epoxy resin free volume fraction analysis, E51-DMM, PEE-DMM, and PDE-DMM.

FIG. 11 is a plot of the fractional free volumes of three epoxy resins, E51-DMM, PEE-DMM, and PDE-DMM, as a function of temperature.

Detailed Description

The raw materials and equipment used in the invention are known products and are obtained by purchasing commercial products.

Example 14 Synthesis of epoxy resin PEE corresponding to 4' - (1-phenylethyl) Bisphenol (BPP)

Adding 4, 4'- (1-phenethyl) bisphenol, epoxy chloropropane and a catalyst benzyl trimethyl ammonium chloride (PTC) into a three-necked flask, ensuring the molar ratio of the 4, 4' - (1-phenethyl) bisphenol to the epoxy chloropropane to be 10:400:0.5, and heating the system in an oil bath for 24 hours at 90 ℃ under the stirring condition to perform condensation reaction. After the reaction is finished, extracting by using ultrapure water, removing a water-soluble catalyst PTC in the product, distilling by using a rotary evaporator to remove epichlorohydrin, and finally further removing residual trace epichlorohydrin in the product by using a vacuum oven at 100 ℃ under the condition of negative pressure to obtain a light yellow transparent viscous liquid, namely the product PEE resin, wherein the reaction process is shown in figure 2, and the infrared spectrogram of the obtained PEE is shown in figure 4.

The epoxy value of the obtained PEE was 0.32 as measured by the hydrochloric acid-acetone method.

EXAMPLE 26 Synthesis of (S) -6- (1, 1-bis (4-hydroxyphenyl) ethyl) diphenyl [ c, e ] [1,2] phosphaphenanthrene (BPD) oxide and its corresponding epoxy PDE

(1) 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO, 10.81g, 0.05mol), 4-hydroxyacetophenone (6.81g, 0.05mol), phenol (23.28g, 5mol) and p-hydroxyphenylsulfonic acid (0.216g) as a catalyst were added to a 250mL three-necked flask equipped with a spherical condenser, and the system was heated in an oil bath for 24 hours to perform condensation reaction while maintaining the temperature of the system at 130 ℃ and under an argon atmosphere by raising the temperature of the system and turning on a stirring device. And after the reaction is finished, the initial product is an orange solid, absolute ethyl alcohol is continuously added into the three-neck flask, the initial product is transferred into a beaker after being dissolved, the mixture is stirred uniformly and precipitated for 12 hours, the filtration is carried out, the solid obtained by the filtration is added into ultrapure water and is filtered again after being stirred, and the intermediate product BPD is obtained after the white solid of the product is dried. The hydrogen spectrum of BPD is shown in FIG. 5 for nuclear magnetism and the infrared spectrum in FIG. 4.

(2) Adding intermediate BPD, epichlorohydrin and a catalyst benzyltrimethylammonium chloride (PTC) into a 500mL three-neck flask with a spherical condenser tube, keeping the molar ratio of the intermediate BPD, the epichlorohydrin and the catalyst benzyltrimethylammonium chloride (PTC) at 10:400:0.5, wherein the excessive epichlorohydrin is used as a solvent, and keeping the system at 90 ℃ and heating in an oil bath for 24 hours under the condition of proper stirring for condensation reaction. After the reaction is finished, extracting the product by using ultrapure water, removing the water-soluble catalyst PTC, removing residual epichlorohydrin in the product by using a rotary evaporator, and finally further removing residual trace epichlorohydrin in the liquid by using a vacuum oven at 100 ℃ under the condition of negative pressure, wherein the finally obtained colorless transparent viscous liquid is the product PDE resin, the reaction process is shown in figure 3, and the infrared spectrogram of the PDE is shown in figure 4.

The epoxy value of the obtained PDE was 0.23 as determined by the hydrochloric acid-acetone method.

Example 3 curing of epoxy resins PEE and PDE

The PEE resin or PDE resin prepared above and DMM were mixed in a ratio of 1: 1 to obtain a liquid mixture. The liquid mixture was stirred at 90 ℃ and poured into a PTFE mould. And curing the mixture at 135 ℃ for 3 hours and 180 ℃ for 3 hours in sequence to obtain a PEE-DDM (polyether-diene monomer) cured sample of the PEE resin and a PDE-DDM cured sample of the PDE resin respectively. The schematic diagram is shown in fig. 1.

The mechanical properties test below used rectangular samples with dimensions of 800mm by 100mm by 4mm and the free damping samples used bars of 180mm by 12mm by 2mm compounded with cold rolled steel.

Comparative example 1 preparation of epoxy curing Material E51-DMM

With DDM as a curing agent, and a commercially available epoxy resin E51 (epoxy value of 0.51) were mixed so that the ratio of E51: DDM molar ratio 1: 1. the mixture was stirred at 90 ℃ and poured into a PTFE mold. And curing the mixture at 135 ℃ for 3 hours and 180 ℃ for 3 hours in sequence to obtain the E51-DMM.

The beneficial effects of the epoxy curing material prepared by the invention are proved by the following experimental examples.

Experimental example 1 dynamic mechanical and mechanical Properties of E51-DDM and PEE-DDM and PDE-DDM

(1) Experimental methods

Dynamic mechanical properties (DMA) were performed on 800mm by 100mm by 4mm rectangular samples of E51-DDM, PEE-DDM, and PDE-DDM, respectively, and the loss modulus (M') versus temperature, and the ratio of loss modulus to storage modulus (tan. delta.) were measured for the samples, and the results are shown in FIG. 6 and Table 1. Where loss modulus (M ") is a measure of the viscous response of a material, the ratio of loss modulus to storage modulus (tan δ) is used to characterize the viscoelastic state or energy dissipation of the material.

(2) Results of the experiment

FIG. 6a) shows the loss modulus (M') as a function of temperature, from which it can be seen that the PEE-DDM has a relatively high loss modulus before 100 ℃ and that the loss modulus of PDE-DMM is somewhat improved over that of E51-DMM. FIG. 6b) is a plot of tan delta versus temperature for E51-DMM, PEE-DMM and PDE-DMM at a vibration frequency of 1 Hz. The damping temperature range of PEE-DMM is 20 ℃ at tan delta >0.6 around 100 ℃, the Tg temperatures of E51-DMM and PDE-DMM are close, the damping temperature ranges of both are 8 ℃ and 36 ℃ at tan delta >0.6, respectively, wherein PDE-DMM is widest at tan delta > 0.6.

The glass transition temperatures (Tg) of E51-DMM, PEE-DMM and PDE-DMM are 174.9 ℃, 105.0 ℃ and 185.7 ℃ respectively, wherein the glass transition temperature of PDE-DMM is higher than that of E51-DMM because the cross-linked network of PDE-DMM is more populated with bulky pendant chain groups than that of E51-DMM, and the cross-linked network of PDE-DMM is less prone to relaxation when the temperature is raised, so the glass transition temperature is higher than that of E51.

The flexural moduli of E51-DMM, PEE-DMM and PDE-DMM are 2756.4MPa, 4101.5MPa and 4273.7MPa respectively, and it is evident that the flexural moduli of the PEE-DMM and PDE-DMM prepared by the invention are significantly higher than those of E51-DMM.

The test results of the three materials DMA show that compared with E51-DDM, the effective damping temperature range and the flexural modulus of two epoxy resin condensate PEE-DMM and PDE-DMM prepared by the invention are obviously improved at the same time, and the requirements of the structural damping integrated material are met.

TABLE 1 dynamic mechanical and mechanical Properties of three epoxy resin cured samples

Experimental example 2 flexural resonance test of damping Performance of E51-DDM, PEE-DDM, and PDE-DDM

(1) Experimental methods

E51, PEE and PDE were cast into 12mm × 180mm × 2mm cured splines E51-DDM, PEE-DDM and PDE-DDM, respectively, according to the method of GB/T16406-. Due to the shrinkage of the sample strips, each cured sample strip was bonded to a 1mm thick cold-rolled steel plate strip using E51 adhesive and DMP-30 curing agent (2, 4, 6-tris (dimethylaminomethyl) phenol) at room temperature, and cured in an oven at 70 ℃ for two hours to obtain composite free damping sample strips. And placing the composite free damping sample strip in the cantilever beam to respectively collect damping data at the temperatures of 30 ℃, 60 ℃, 90 ℃, 100 ℃ and 120 ℃, and selecting a delta3dB value made by a second damping peak as a reference data point to obtain the damping ratio of the free damping sample strip at different temperatures.

(2) Results of the experiment

As the results are shown in Table 2, it can be seen that as the temperature increases, the viscosity of the PEE-DDM and PDE-DDM materials of the invention increases, the damping ratio simultaneously increases with increasing temperature, and the peak frequency of Delta3db decreases. When the temperature is above 90 ℃, the damping ratio of PEE-DDM to PDE-DDM can be found to be significantly higher than that of E51-DDM.

Especially for PEE-DDM, the material exhibits re-plasticity after 110 ℃, after which the damping ratio of the material is up to 2.68%. The experimental results prove that the modulus of the PEE-DDM material prepared by the hard filling method is rapidly reduced along with the temperature rise, and meanwhile, the material has better heavy plasticity and shows the shape memory characteristic at normal temperature. Although the decrease of the storage modulus of the PDE-DMM is slower than that of the PEE-DMM, the damping effect at about 100 ℃ is slightly inferior to that of the PEE-DMM, but the increase of the damping ratio of the PDE-DMM is obvious along with the temperature rise, the damping ratio reaches 0.711% at 120 ℃, and the damping performance is obviously superior to that of the E51-DDM.

TABLE 2 damping Performance flexural resonance test results for E51-DDM, PEE-DDM, and PDE-DDM free damped splines

Experimental example 3 shape memory Property testing of E51-DDM and PEE-DDM and PDE-DDM

(1) Experimental methods

Taking a PEE-DMM sample strip, gradually heating from room temperature until the sample strip can be bent, keeping the temperature for 5 minutes, bending the sample strip into a required shape by using an external force, and keeping the external force. Then, the sample was returned to room temperature while maintaining the external force, the external force was released, and the change in the shape of the sample was observed.

In addition, by adopting the same method, the PEE-DMM sample strip is heated and bent, and under the condition of keeping the external force, the sample strip is recovered to the room temperature, then is heated to the bending temperature, the external force is released, and the change of the shape of the sample strip is observed.

(2) Results of the experiment

Experiments show that the PEE-DMM keeps a higher modulus at normal temperature and cannot deform, the modulus of the PEE-DMM is rapidly reduced along with the increase of the temperature, the PEE-DMM can be completely reshaped to 110 ℃, and when the temperature reaches 130 ℃, the PEE-DMM can be placed in an environment of 130 ℃ for five minutes, so that PEE-DMM splines can be folded, materials with different shapes (as shown in figure 7) can be obtained, and the PEE-DMM has excellent superplasticity. After the bars were placed back at room temperature, the higher modulus was restored and the deformability was lost and the bars remained in the shape they were bent at 130 ℃. When the PEE-DMM sample strip is heated to 130 ℃ again, the external force is released, and the sample strip recovers the shape before the initial deformation.

Therefore, the above experiments demonstrate that the shape of the PEE-DMM material of the present invention can be reshaped after temperature rise and that the deformability of the material is reversible.

Experimental example 4 Low field Nuclear magnetic testing of E51-DDM, PEE-DDM, and PDE-DDM

(1) Experimental methods

And cutting the sample into fragments, adding the fragments into a nuclear magnetic tube, and testing the transverse relaxation time of the material at intervals of 10 ℃ to obtain a low-field nuclear magnetic transverse relaxation time change diagram at the temperature of 30-150 ℃.

(2) Results of the experiment

Results as shown in fig. 8, fig. 8 depicts the first relaxation peak versus temperature line graph (a) and relaxation time curves at different temperatures (b) for the three epoxy resins. The transverse relaxation time of the material generally rises with the rise of temperature, because the relaxation time of low-field nuclear magnetism mainly comes from transverse relaxation between hydrogen nuclei, and when a molecular network is relaxed, the distance between atoms increases, and the transverse relaxation time becomes longer. As seen in FIG. 8(a), the first relaxation peaks of PEE-DMM and PDE-DMM show a difference from that of E51-DMM, in that E51-DMM shows a sudden increase in transverse relaxation time after 130 ℃, while PEE-DMM and PDE-DMM show sudden increases in transverse relaxation time at 70 ℃ and 100 ℃, respectively, indicating that both materials of PEE-DMM and PDE-DMM undergo relaxation of segments at lower temperatures.

Experimental example 5 broad Screen dielectric Curve testing of E51-DDM, PEE-DDM and PDE-DDM

(1) Experimental methods

The sample is made into a wafer with the thickness of 0.4mm and the diameter of 20mm, a wide-screen dielectric impedance instrument of Novocontrol is used for continuously heating the wafer from room temperature to 200 ℃ in a nitrogen gas environment, and the dielectric properties of the material at different temperatures are tested at intervals of 10 ℃.

(2) Results of the experiment

The results are shown in FIG. 9, FIG. 9a) depicts the broadscreen dielectric curves of three epoxy resin cures, and FIG. 9b) is a Havriliak-Negami equation fit data of the gamma relaxation peaks of the three materials, more intuitively depicting the difference of gamma relaxation and the process as a function of temperature. Gamma relaxation results from the rotation of the aryl ether bond and the ether bond, while different pendant chains have different effects on the rotation of the aryl ether bond and the ether bond. From the dielectric loss and temperature dependent spectrum of the broad screen dielectric, the gamma relaxation temperature of PDE-DMM is-20 deg.C, that of PEE-DMM is-40 deg.C, and that of E51-DMM is-55 deg.C. As the material reaches the deformation temperature with the increase of temperature, the plasticity of the material is stronger due to higher gamma relaxation temperature, so the PDE-DMM and the PEE-DMM prepared by the invention have better plasticity.

Experimental example 6 in silico simulation of E51-DDM and PEE-DDM and PDE-DDM

(1) Experimental methods

Computer modeling of the epoxy resin was performed according to the logic shown in fig. 10, and the model was analyzed for free volume fraction (FFV), which gave the results of fig. 11. An increase in the FFV of the material means an increase in the flowability of the material, an increase in the sensitivity to deformation and thus an increase in the plasticity of the material.

(2) Results of the experiment

As seen in FIG. 11, at room temperature, the PEE-DMM and PDE-DMM prepared by the present invention have larger FFV than PDE-DMM, indicating that the introduction of the pendant chains of the present invention enhances the FFV of the material. Meanwhile, as the temperature rises, the PEE-DMM shows greater fluctuation, and the free volume fraction thereof sharply rises along with the rise of the temperature; whereas the FFV changes of PDE-DMM and E51-DMM are relatively smooth. Therefore, the PEE-DMM prepared by the invention has better plasticity.

In conclusion, the invention prepares two novel cured epoxy resins PEE-DMM and PDE-DMM by a hard filling method. Compared with the common epoxy resin E51-DMM, the epoxy resin PEE-DMM and the PDE-DMM prepared by the invention have the advantages of remarkably widened damping temperature range, excellent mechanical properties (particularly bending modulus) and reversible shape memory property, are excellent intrinsic structure damping integrated materials, and have wide application prospects in the fields of aerospace and the like.

Claims

1. The application of the structural damping integrated material in preparing the excellent intrinsic structural damping integrated material with obviously widened damping temperature range, excellent mechanical property and reversible shape memory characteristic is characterized in that: the structural damping integrated material is obtained by carrying out a curing reaction on epoxy resin and a curing agent; the curing agent is 4, 4' -diaminodiphenylmethane, and the molar ratio of the epoxy resin to the curing agent is 1: 1;

the structure of the epoxy resin is shown as formula 3 or formula 4:

2. Use according to claim 1, characterized in that: the epoxy resin is prepared from bisphenol compounds and epoxy chloropropane, wherein the structure of the bisphenol compounds is shown in formula 1 or formula 2:

3. use according to claim 2, characterized in that: the raw materials for preparing the epoxy resin also comprise a catalyst;

the molar ratio of the bisphenol compound to the epichlorohydrin to the catalyst is 10: (300-500): (0.3-1).

4. Use according to claim 3, characterized in that: the catalyst is benzyl trimethyl ammonium chloride;

the molar ratio of the bisphenol compound to the epichlorohydrin to the catalyst is 10:400: 0.5.

5. use according to any one of claims 1 to 4, characterized in that: the preparation method of the structural damping integrated material comprises the following steps:

(1) uniformly mixing the bisphenol compound and epoxy chloropropane, and reacting to obtain epoxy resin; the structure of the bisphenol compound is shown in formula 1 or formula 2:

(2) uniformly mixing the epoxy resin obtained in the step (1) with a curing agent, and curing to obtain the epoxy resin;

the curing agent is 4, 4' -diaminodiphenylmethane, and the molar ratio of the epoxy resin to the curing agent is 1: 1.

6. use according to claim 5, characterized in that: in the step (1), the reaction is carried out under the action of a catalyst; the reaction temperature is 80-100 ℃, and the reaction time is 20-30 hours.

7. Use according to claim 6, characterized in that: in the step (1), the catalyst is benzyltrimethylammonium chloride; the reaction temperature was 90 ℃ and the time was 24 hours.

8. Use according to claim 5, characterized in that: in the step (2), the curing conditions are as follows: curing was carried out at 135 ℃ for 3 hours and then at 180 ℃ for 3 hours.

9. Use according to claim 5, characterized in that: the preparation method of the bisphenol compound shown in the formula 2 comprises the following steps: mixing 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 4-hydroxyacetophenone and phenol uniformly, and reacting to obtain the final product.

10. Use according to claim 9, characterized in that: the reaction is carried out under the action of a catalyst p-hydroxybenzene sulfonic acid;

the reaction temperature is 110-150 ℃, and the reaction time is 20-30 hours;

the reaction is carried out under the protection of inert gas;

the molar ratio of the 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to the 4-hydroxyacetophenone to the phenol is (0.5-1.5): (0.5-1.5): 100.

11. use according to claim 10, characterized in that: the molar ratio of the 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to the 4-hydroxyacetophenone to the phenol is 1: 1: 100.