CN115819845A - Filler modification method, modified filler and filled heat-conducting epoxy resin - Google Patents
Filler modification method, modified filler and filled heat-conducting epoxy resin Download PDFInfo
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Abstract
A filler modification method, a modified filler and filled heat-conducting epoxy resin belong to the technical field of filled epoxy resin and overcome the defects of poor dispersibility of the heat-conducting filler and high viscosity of a composite system in the prior art. The filler modification method comprises the following steps: step 1, etching the filler by using an alkaline solution; step 2, coating polydopamine on the surface of the etched filler to prepare a polydopamine modified filler; and 3, modifying the polydopamine modified filler by using a coupling agent. The three steps of synergistic action obviously reduce the viscosity of the epoxy resin precursor, improve the processing manufacturability of the epoxy resin precursor, and synergistically improve the heat conduction, electric and anti-cracking performances of the epoxy material.
Description
Technical Field
The invention belongs to the technical field of filled epoxy resin, and particularly relates to a filler modification method, a modified filler and filled heat-conducting epoxy resin.
Background
The key of the core equipment is for large-scale construction of extra-high voltage engineering. With the high-speed development of the power transmission and transformation industry, the number of the extreme service scenes of high temperature, low temperature, high electric field and the like in the extra-high voltage equipment is further increased, and more urgent needs are brought to the research, development and application of high-heat-conductivity electrical insulating materials.
At present, two ways are mainly adopted for regulating and controlling the thermal conductivity of the epoxy resin at home and abroad: (1) The molecular chain structure of the epoxy resin is designed through chemical grafting or molding control, so that the orientation degree and the crystallinity of a cured epoxy resin are improved, and the intrinsic thermal conductivity of the epoxy resin is improved; (2) The epoxy resin matrix is filled with the high-thermal-conductivity filler, and an effective thermal-conductivity passage in the polymer matrix is constructed by using the filler, so that the thermal conductivity of the epoxy resin composite material is improved. However, the epoxy resin with high intrinsic thermal conductivity has high melting point, high viscosity, poor fluidity, complex preparation and synthesis process, unstable performance and high difficulty in large-scale and industrialized production. The improvement of the heat conductivity of the filling type heat conduction material mainly depends on the self heat conductivity of the filler, the filling amount of the filler, the compounding mode of the filler and the matrix and the like, and the filling type heat conduction material is widely applied to the field of industrial production due to the characteristics of simple preparation process, low production cost and the like.
The filling type heat conduction material mainly takes a polymer as a matrix, and is filled with metal, inorganic ceramic, carbon material particles or hybrid filler with high heat conduction, so that the obtained composite material can maintain the excellent sealing property and processability of the polymer matrix and simultaneously improve the heat conduction performance of the material. For equipment such as a dry smoothing reactor, a dry high-voltage direct-current sleeve and the like, the epoxy resin encapsulation mostly adopts a vacuum pouring process, and the existing filling type heat-conducting epoxy material cannot meet the requirements of the extra-high voltage equipment due to the problems of poor dispersibility of filling particles, large viscosity of a composite system and the like.
Disclosure of Invention
Therefore, the technical problem to be solved by the invention is to overcome the defects of poor dispersibility of the heat-conducting filler and high viscosity of a composite system in the prior art, so as to provide a filler modification method, a modified filler and filled heat-conducting epoxy resin.
Therefore, the invention provides the following technical scheme.
In a first aspect, the present invention provides a method of modifying a filler comprising the steps of:
step 1, etching the filler by using an alkaline solution;
step 2, coating polydopamine on the surface of the etched filler to prepare a polydopamine modified filler;
and 3, modifying the polydopamine modified filler by using a coupling agent.
Further, the step 1 comprises:
step 101, weighing a filler;
step 102, uniformly dispersing the filler in an alkaline solution with the pH value of 7-13, and performing reaction etching for 0.5-2 hours at the temperature of 55-65 ℃;
and 103, separating the etched filler, washing and drying.
Further, the step 1 satisfies at least one of the following conditions:
(1) The filler comprises at least one of alumina, silica and boron nitride;
(2) The filler is micron-sized;
(3) The alkaline solution is NaOH solution or tetramethyl ammonium hydroxide solution;
(4) Deionized water is adopted for washing;
(5) The drying temperature is 60-100 ℃, and the drying time is 5-20 h.
Further, the step 2 comprises:
step 201, preparing a dopamine hydrochloride solution;
step 202, adding the etched filler into a dopamine hydrochloride solution, uniformly stirring and dispersing, then adjusting the pH value to 8-8.5, stirring at room temperature for 4-20 h, and stirring at the speed of 500-800 r/min;
and step 203, filtering, washing and drying to obtain the polydopamine modified filler.
Further, the mass ratio of the dopamine hydrochloride to the filler is 1: (4-20).
Further, in the step 3, the coupling agent comprises a silane coupling agent and a titanate coupling agent;
the mass ratio of the silane coupling agent to the titanate coupling agent is (2-5): (0.5-1).
Further, the step 3 comprises:
301, mixing a silane coupling agent and ethanol, and stirring for 30-60 min at 25-35 ℃;
step 302, adding a titanate coupling agent, and stirring for 30-60 min at 25-35 ℃;
step 303, heating to 70-90 ℃, adding the polydopamine modified filler prepared in the step 2, stirring, condensing and refluxing for 1-2 hours;
step 304, filtering, washing and drying.
Further, the step 3 satisfies at least one of the following conditions:
(1) The mass of the silane coupling agent is 2-5 wt% of the mass of the filler;
(2) The mass of the titanate coupling agent is 0.5 to 1 weight percent of the mass of the filler;
(3) The mass of the ethanol is 2 to 3 times of that of the filler;
(4) The ethanol accounts for 95-98% of the mass fraction of the ethanol.
In a second aspect, there is provided a modified filler made by the above method.
In a third aspect, a filled heat-conducting epoxy resin is provided, which comprises the modified filler prepared by the method and an epoxy resin;
the mass ratio of the modified filler to the epoxy resin is (4-7): (3-6).
In step 103, the washing is: and washing the filler etched by the alkaline solution for 3-5 times by using deionized water.
In step 203, the washing is: washing the polydopamine modified filler for 3-5 times by using deionized water, and washing away unreacted dopamine hydrochloride; drying is carried out in a forced air drying oven at 60-100 ℃ for 5-20 hours.
In the step 301, the stirring speed is 500-800 r/min, and silane coupling agents such as KH560 and KH550 are used; stirring for 30-60 min at 25-35 ℃ for alcoholysis.
In step 302, stirring at a speed of 500-800 r/min, and using GR-311, GR-102 and the like as titanate coupling agents; stirring for 30-60 min at 25-35 ℃ for further alcoholysis.
In step 303, the stirring speed is 500-800 r/min.
In step 304, ethanol is adopted to wash for 3 to 5 times to remove the unreacted coupling agent, and finally the washing speed is between 60 and 100 o And C, drying for 4-10 hours for later use.
The technical scheme of the invention has the following advantages:
1. the invention provides a filler modification method, which comprises the following steps: step 1, etching the filler by using an alkaline solution; step 2, coating polydopamine on the surface of the etched filler to prepare a polydopamine modified filler; and 3, modifying the polydopamine modified filler by using a coupling agent.
According to the invention, alkaline solution etching, polydopamine coating and coupling agent grafting modification are sequentially adopted, so that the binding capacity of filling particles and an epoxy resin matrix can be enhanced, the filler dispersibility is improved, the viscosity of a filling type heat-conducting epoxy resin precursor is reduced, and the fluidity of the precursor is enhanced. The alkaline solution etching is used for increasing the surface roughness and the number of active groups of the particles, improving the binding capacity with a polydopamine coated interface and enhancing the toughness of the material. On one hand, the poly-dopamine coating provides rich reaction groups and provides a good grafting platform for modifying a coupling agent, and on the other hand, a proper amount of dopamine coating is beneficial to enhancing the insulating property of the composite material. The coupling agent modification can enhance the interface combination between the filler particles and the epoxy resin matrix and reduce the interface thermal resistance.
Dopamine can undergo auto-oxidative polymerization in a weakly alkaline environment to form a polydopamine structure (PDA) which can be coated on almost any organic and inorganic base materials, the PDA structure contains a large number of hydroxyl groups and amino groups and is a good secondary reaction platform, the PDA is coated on the surface of a filler and then is combined with a coupling agent, so that the grafting modification degree of the coupling agent can be greatly improved, the interface combination between the filler and an epoxy substrate is improved, the system viscosity is remarkably reduced, the comprehensive performance of the epoxy material, such as power, electricity and heat, is improved, and the insulation performance of the filler/epoxy composite material can be remarkably improved by coating the polydopamine.
The high-thermal-conductivity ceramic filler has large surface inertia and few reactive functional groups, is modified by a single coupling agent, has low reaction grafting degree of filler particles and the coupling agent, and has weak effect of improving the properties of epoxy condensate such as heat, electricity and the like; the coating modification of the single polydopamine is also beneficial to improving the interface bonding between the filler and the epoxy resin, but the polydopamine is easy to fall off, and the polydopamine and the epoxy resin matrix are connected by Van der Waals acting force or hydrogen bonds, so that the interface bonding is weak, and the viscosity reduction effect on the epoxy resin precursor is weak. According to the invention, the surface roughness and the number of polar groups of the heat-conducting filler are increased by alkaline solution etching, so that the poly-dopamine is more firmly coated and is not easy to fall off. Meanwhile, the coated polydopamine is used as a secondary reaction platform and is further modified in a synergistic manner with a silane coupling agent and a titanate coupling agent, so that the modified grafting degree of the coupling agent is improved, the viscosity of the epoxy resin precursor is obviously reduced under the synergistic effect of the polydopamine, the silane coupling agent and the titanate coupling agent, the processing manufacturability of the epoxy resin precursor is improved, and the heat conduction performance, the electrical performance, the cracking resistance performance and other performances of the epoxy material are synergistically improved.
2. According to the filler modification method provided by the invention, the coupling agent comprises a silane coupling agent and a titanate coupling agent; the mass ratio of the silane coupling agent to the titanate coupling agent is (2-5): (0.5-1). The silane coupling agent is helpful for improving the electrical performance of the epoxy material, but the modification degree is low; the titanate coupling agent is weakly acidic on one side, so that the hydrolysis of the silane coupling agent is promoted, and the grafting degree of the silane coupling agent and the filler particles is improved; on the other hand, the adopted titanate coupling agent has a large number of soft long-carbon bond alkyl structures, can improve the intermiscibility with a polymer matrix, causes the change of the surface energy on the inorganic filler interface, has the functions of flexibility and stress transfer, generates a self-lubricating effect, greatly reduces the viscosity, improves the processing technology and enhances the fluidity of the precursor. The compound coupling agent of the silane coupling agent and the titanate coupling agent can effectively realize the synergistic improvement of the heat conduction, the electricity and the processing technology performance of the epoxy material.
3. The filled heat-conducting epoxy resin provided by the invention comprises the prepared modified filler and epoxy resin; the mass ratio of the modified filler to the epoxy resin is (4-7): (3-6).
The filled heat-conducting epoxy resin maintains high heat conduction and high insulation cracking resistance, reduces the viscosity of an epoxy resin total system, improves the dispersibility of particles in the total system, and enhances the fluidity of the epoxy resin composite material.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.
FIG. 1 is a graph of the viscosity of the precursor mixture of example 1 at 75 ℃ as a function of time.
FIG. 2 is a graph of the viscosity of the precursor mixture of example 2 at 75 ℃ as a function of time.
FIG. 3 is a graph of the viscosity of the precursor mixture of example 3 at 75 ℃ as a function of time.
FIG. 4 is a graph of the viscosity of the mixture precursor of example 4 at 75 ℃ as a function of time.
Detailed Description
The following examples are provided to further understand the present invention, not to limit the scope of the present invention, but to provide the best mode, not to limit the content and the protection scope of the present invention, and any product similar or similar to the present invention, which is obtained by combining the present invention with other prior art features, falls within the protection scope of the present invention.
The examples do not indicate specific experimental procedures or conditions, and can be performed according to the procedures or conditions of the conventional experimental procedures described in the literature in the field. The reagents or instruments used are not indicated by manufacturers, and are all conventional reagent products which can be obtained commercially.
Example 1
The embodiment provides a filler modification method, which comprises the following steps:
step 1, spherical alumina filler (average particle size 50 μm) was added to a tetramethylammonium hydroxide solution of pH =12 and etched at 60 ℃ for 1.5 hours. Separating out the etched spherical alumina filler, cleaning for 3 times by using deionized water, and drying for 12 hours at the temperature of 80 ℃.
And 2, adding the washed and dried filler into a dopamine hydrochloride solution, adjusting the pH to about 8 by adopting a Tris buffer solution (Tris (hydroxymethyl) aminomethane), stirring at room temperature for 500r/min, and coating for 4 hours, wherein the mass ratio of the filler to the dopamine hydrochloride is 4. Filtering, washing with deionized water for 3 times, and drying at 80 deg.C for 12h to obtain polydopamine modified filler.
And 3, weighing 95% ethanol with 2 times of the mass of the filler, adding the ethanol into the reaction kettle, stirring at the rotating speed of 800r/min, adding 2wt% of silane coupling agent KH560 with the mass of the filler, adjusting the temperature of the reaction kettle to 30 ℃, and stirring for alcoholysis for 30min.
Then adding 0.5wt% of titanate coupling agent GR-311 by weight of filler, keeping the reaction temperature at 30 ℃, and stirring for 30min at the rotating speed of 800r/min for further alcoholysis.
And then, heating the temperature of the reaction kettle to 80 ℃, adding the polydopamine modified filler prepared in the step 2, and stirring, condensing and refluxing for 2 hours at the rotating speed of 800r/min.
After the reaction is finished, the mixed system is filtered, washed by ethanol for 3 times and dried for 4 hours at 80 ℃.
The embodiment provides a filled heat-conducting epoxy resin, and the modified filler prepared in the embodiment is mixed with an epoxy resin in a mass ratio of 7.
The mixture precursor was tested for viscosity change at 75 deg.C and a filled thermally conductive epoxy resin was vacuum cast at 75 deg.C process temperature to 85 deg.C o C4 hours +130 o C12 hours curing System for curing.
Example 2
The embodiment provides a filler modification method, which comprises the following steps:
step 1, spherical silica filler (average particle size 30 μm) was added to a tetramethylammonium hydroxide solution of pH =13 and etched at 60 ℃ for 1 hour. Separating out the etched spherical alumina filler, washing with deionized water for 4 times, and drying at 80 ℃ for 12h.
And 2, adding the washed and dried filler into a dopamine hydrochloride solution, adjusting the pH to 8 by adopting a Tris buffer solution, stirring at the room temperature of 600r/min, and coating for 10 hours, wherein the mass ratio of the filler to the dopamine hydrochloride is 10. Filtering, washing with deionized water for 3 times, and drying at 80 deg.C for 12h to obtain polydopamine modified filler.
And 3, weighing 95% ethanol with 2 times of the mass of the filler, adding the ethanol into the reaction kettle, stirring at the rotating speed of 800r/min, adding 5wt% of silane coupling agent KH550 with the mass of the filler, adjusting the temperature of the reaction kettle to 30 ℃, and stirring for alcoholysis for 30min.
Then adding titanate coupling agent GR-311 accounting for 1 weight percent of the mass of the filler, keeping the reaction temperature at 30 ℃, and stirring for 30min at the rotating speed of 800r/min for further alcoholysis.
And then, heating the temperature of the reaction kettle to 80 ℃, adding the polydopamine modified filler prepared in the step 2, and stirring, condensing and refluxing for 2 hours at the rotating speed of 800r/min.
After the reaction is finished, the mixed system is filtered, washed by ethanol for 3 times and dried for 4 hours at 80 ℃.
The embodiment provides a filled heat-conducting epoxy resin, and the modified filler prepared in the embodiment is mixed with an epoxy resin in a mass ratio of 7.
The mixture precursor was tested for viscosity change at 75 deg.C and a filled thermally conductive epoxy resin was vacuum cast at 75 deg.C process temperature to 85 deg.C o C4 hours +130 o C12 hours curing System for curing.
Example 3
The embodiment provides a filler modification method, which comprises the following steps:
step 1, a boron nitride filler (average particle size of 10 μm) was added to a NaOH solution of pH =10 and etched at 60 ℃ for 0.5 hour. Separating out the etched spherical alumina filler, cleaning for 3 times by using deionized water, and drying for 12 hours at the temperature of 80 ℃.
And 2, adding the washed and dried filler into a dopamine hydrochloride solution, adjusting the pH to 8 by adopting a Tris buffer solution, stirring at room temperature for 500r/min, and coating for 20 hours, wherein the mass ratio of the filler to the dopamine hydrochloride is 20. Filtering, washing with deionized water for 3 times, and drying at 80 deg.C for 12h to obtain polydopamine modified filler.
And 3, weighing 95% ethanol with 2 times of the mass of the filler, adding the ethanol into the reaction kettle, stirring at the rotating speed of 800r/min, adding 5wt% of silane coupling agent KH560 with the mass of the filler, adjusting the temperature of the reaction kettle to 30 ℃, and stirring for alcoholysis for 30min.
Then adding 1wt% of titanate coupling agent GR-311 of filler mass, keeping the reaction temperature at 30 ℃, and stirring at the rotating speed of 800r/min for 30min for further alcoholysis.
And then, heating the temperature of the reaction kettle to 80 ℃, adding the polydopamine modified filler prepared in the step 2, and stirring, condensing and refluxing for 2 hours at the rotating speed of 800r/min.
After the reaction is finished, the mixed system is filtered, washed by ethanol for 3 times and dried for 4 hours at 80 ℃.
The embodiment provides a filled heat-conducting epoxy resin, and the modified filler prepared in the embodiment is mixed with an epoxy resin in a mass ratio of 4.
The mixture precursors were tested for viscosity change at 75 ℃ and filled thermally conductive epoxy was vacuum cast at 75 ℃ process temperature to 85 ℃ o C4 hours +130 o C12 hours curing System for curing.
Example 4
The embodiment provides a filler modification method, which comprises the following steps:
step 1, an alumina filler (average particle size 50 μm) was added to a NaOH solution of pH =10 and etched at 60 ℃ for 2 hours. And separating the etched alumina filler, cleaning for 3 times by using deionized water, and drying for 12 hours at 80 ℃.
And 2, adding the washed and dried filler into a dopamine hydrochloride solution, adjusting the pH to 8 by adopting a Tris buffer solution, stirring at room temperature for 500r/min, and coating for 20 hours, wherein the mass ratio of the filler to the dopamine hydrochloride is 20. Filtering, washing with deionized water for 3 times, and drying at 80 deg.C for 12h to obtain polydopamine modified filler.
And 3, weighing 95% ethanol with 2 times of the mass of the filler, adding the ethanol into the reaction kettle, stirring at the rotating speed of 800r/min, adding 3wt% of silane coupling agent KH550 with the mass of the filler, adjusting the temperature of the reaction kettle to 30 ℃, and stirring for alcoholysis for 30min.
Then adding 0.5wt% of titanate coupling agent GR-102 based on the mass of the filler, keeping the reaction temperature at 30 ℃, and stirring for 30min at the rotating speed of 800r/min for further alcoholysis.
And then, heating the temperature of the reaction kettle to 80 ℃, adding the polydopamine modified filler prepared in the step 2, and stirring, condensing and refluxing for 2 hours at the rotating speed of 800r/min.
After the reaction is finished, the mixed system is filtered, washed by ethanol for 3 times and dried for 4 hours at 80 ℃.
The embodiment provides a filled heat-conducting epoxy resin, and the modified filler prepared in the embodiment is mixed with an epoxy resin in a mass ratio of 7.
The mixture precursor was tested for viscosity change at 75 deg.C and a filled thermally conductive epoxy resin was vacuum cast at 75 deg.C process temperature to 85 deg.C o C4 hours +130 o C12 hours curing System for curing.
Comparative example 1
This comparative example provides a filled thermally conductive epoxy resin, substantially the same as example 1, except that the filler of this comparative example is not modified.
Comparative example 2
This comparative example provides a filled thermally conductive epoxy resin, substantially the same as example 2, except that the filler of this comparative example is not modified.
Comparative example 3
This comparative example provides a filled thermally conductive epoxy resin, substantially the same as example 3, except that the filler of this comparative example is not modified.
Comparative example 4
The comparative example provides a filled type heat conductive epoxy resin, which is substantially the same as example 1 except that the method for modifying the filler of the comparative example does not employ an alkaline solution for etching.
Comparative example 5
This comparative example provides a filled thermally conductive epoxy resin, substantially the same as example 1, except that the method of modifying the filler of this comparative example is not coated with polydopamine.
Test examples
The method is respectively determined according to the standard GB/T22314-2008 plastic epoxy resin viscosity determination method, ISO22007-2-2008 plastic thermal conductivity and thermal diffusivity determination, GB/T1408.1-2006/IEC 60243-1:1998 test method for electrical strength of insulating material, GBT 31838.2-2019 dielectric and resistance characteristics of solid insulating material, and testing properties of cured epoxy resin such as viscosity, thermal conductivity, alternating current breakdown strength and volume resistivity; using a high and low temperature test chamber, at 0.3 o C/min Cooling Rate, 0% RH humidityTemperature range of: room temperature of-60 deg.c o And C, testing the cracking resistance of the cured epoxy resin, wherein the test result is shown in Table 1.
TABLE 1 mixture precursor viscosity and epoxy resin curing Properties
As can be seen from Table 1, the viscosity of the epoxy system prepared by using the filler modified by the method of the present invention is significantly reduced, and the thermal conductivity, electrical properties and crack resistance of the epoxy system are significantly improved compared with those of the unmodified system.
FIGS. 1-4 show the viscosity of the precursor mixture of examples 1-4 at 5min after heating to 75 deg.C, and it can be seen that the viscosity of each example reaches the lowest value after stabilizing at 75 deg.C for 3-5 min, and the lowest viscosity of examples 1-4 is about 265, 760, 990 and 435 mPas, respectively, which is significantly lower than that of the unmodified system of comparative examples 1-3. Furthermore, at 75 ℃ the epoxy resin started to crosslink slowly with time, the viscosity of the epoxy resin of each example increased gradually, but after 2h the viscosity was still less than the lowest viscosity of the unmodified systems of comparative examples 1 to 3. The modification method provided by the scheme can greatly reduce the viscosity of the epoxy resin and prolong the operable time of the epoxy resin.
It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications of the invention may be made without departing from the spirit or scope of the invention.
Claims (10)
1. A method of modifying a filler, comprising the steps of:
step 1, etching the filler by using an alkaline solution;
step 2, coating polydopamine on the surface of the etched filler to prepare a polydopamine modified filler;
and 3, modifying the polydopamine modified filler by using a coupling agent.
2. The filler modification method according to claim 1, characterized in that step 1 comprises:
step 101, weighing a filler;
step 102, uniformly dispersing the filler in an alkaline solution with the pH value of 7-13, and performing reaction etching for 0.5-2 hours at the temperature of 55-65 ℃;
and 103, separating the etched filler, washing and drying.
3. Filler modification method according to claim 2, characterized in that step 1 fulfils at least one of the following conditions:
(1) The filler comprises at least one of alumina, silica and boron nitride;
(2) The filler is micron-sized;
(3) The alkaline solution is NaOH solution or tetramethyl ammonium hydroxide solution;
(4) Deionized water is adopted for washing;
(5) The drying temperature is 60-100 ℃, and the drying time is 5-20 h.
4. Filler modification method according to claim 1, characterized in that said step 2 comprises:
step 201, preparing a dopamine hydrochloride solution;
step 202, adding the etched filler into a dopamine hydrochloride solution, uniformly stirring and dispersing, then adjusting the pH value to 8-8.5, stirring at room temperature for 4-20 h, and stirring at the speed of 500-800 r/min;
and 203, filtering, washing and drying to obtain the polydopamine modified filler.
5. The filler modification method according to claim 4, wherein the mass ratio of dopamine hydrochloride to filler is 1: (4-20).
6. The filler modification method according to claim 1, wherein in the step 3, the coupling agent comprises a silane coupling agent and a titanate coupling agent;
the mass ratio of the silane coupling agent to the titanate coupling agent is (2-5): (0.5-1).
7. The filler modification method according to claim 6, characterized in that said step 3 comprises:
301, mixing a silane coupling agent and ethanol, and stirring for 30-60 min at 25-35 ℃;
step 302, adding a titanate coupling agent, and stirring for 30-60 min at 25-35 ℃;
step 303, heating to 70-90 ℃, adding the polydopamine modified filler prepared in the step 2, stirring, condensing and refluxing for 1-2 hours;
step 304, filtering, washing and drying.
8. Filler modification method according to claim 7, characterized in that step 3 fulfils at least one of the following conditions:
(1) The mass of the silane coupling agent is 2-5 wt% of the mass of the filler;
(2) The mass of the titanate coupling agent is 0.5 to 1 weight percent of the mass of the filler;
(3) The mass of the ethanol is 2 to 3 times of that of the filler;
(4) The ethanol accounts for 95-98% of the mass fraction of the ethanol.
9. A modified filler made according to the method of any one of claims 1-8.
10. A filled thermally conductive epoxy resin comprising the modified filler prepared by the method according to any one of claims 1 to 8 and an epoxy resin;
the mass ratio of the modified filler to the epoxy resin is (4-7): (3-6).
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| CN110903608A (en) * | 2019-12-13 | 2020-03-24 | 华北电力大学 | High-thermal-conductivity epoxy composite material and preparation method thereof |
| CN111057347A (en) * | 2019-12-10 | 2020-04-24 | 西安科技大学 | Preparation method of dopamine-modified boron nitride high-thermal-conductivity composite material |
| CN111440511A (en) * | 2020-05-11 | 2020-07-24 | 韩永洲 | High-thermal-conductivity nano Al2O3Modified epoxy resin super-hydrophobic coating and preparation method thereof |
| CN111777917A (en) * | 2020-06-18 | 2020-10-16 | 东北大学 | Preparation method of modified etched basalt scale/epoxy resin composite coating |
| CN113698736A (en) * | 2021-10-09 | 2021-11-26 | 深圳市鑫奕龙达电子有限公司 | Halogen-free flame-retardant heat-conducting wire insulating layer and preparation method thereof |
| KR20220035659A (en) * | 2020-09-14 | 2022-03-22 | 주식회사 한솔케미칼 | Resin composition for dissipating heat heat-dissipating member and electronic device |
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| CN111057347A (en) * | 2019-12-10 | 2020-04-24 | 西安科技大学 | Preparation method of dopamine-modified boron nitride high-thermal-conductivity composite material |
| CN110903608A (en) * | 2019-12-13 | 2020-03-24 | 华北电力大学 | High-thermal-conductivity epoxy composite material and preparation method thereof |
| CN111440511A (en) * | 2020-05-11 | 2020-07-24 | 韩永洲 | High-thermal-conductivity nano Al2O3Modified epoxy resin super-hydrophobic coating and preparation method thereof |
| CN111777917A (en) * | 2020-06-18 | 2020-10-16 | 东北大学 | Preparation method of modified etched basalt scale/epoxy resin composite coating |
| KR20220035659A (en) * | 2020-09-14 | 2022-03-22 | 주식회사 한솔케미칼 | Resin composition for dissipating heat heat-dissipating member and electronic device |
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