Functional BN-rGO in-situ polymerization polyurethane heat-conducting insulating material and preparation method thereof
阅读说明：本技术 一种功能化BN-rGO原位聚合聚氨酯导热绝缘材料及其制法 (Functional BN-rGO in-situ polymerization polyurethane heat-conducting insulating material and preparation method thereof ) 是由 程恩志 于 2020-06-30 设计创作，主要内容包括：本发明涉及导热绝缘材料技术领域,且公开了一种功能化BN-rGO原位聚合聚氨酯导热绝缘材料,还原氧化石墨烯的片层之间相互叠加,形成大量褶皱,经过超声,得到BN-rGO复合材料,BN片层构成连续的三维网状结构,减少复合材料之间的界面热阻,为聚氨酯复合材料构筑了优异的三维导热网络,BN隔断rGO之间电子传输,确保复合材料良好的电绝缘性能,在Tris缓冲液中,多巴胺发生自聚合形成聚多巴胺,与BN-rGO复合材料反应,得到聚多巴胺修饰的功能化BN-rGO,再以聚四氢呋喃二醇和二苯甲烷二异氰酸酯为原料,得到功能化BN-rGO原位聚合聚氨酯导热绝缘材料,改善BN-rGO在聚氨酯中的分散性和相容性,使得聚氨酯具有优异的导热性和绝缘性。(The invention relates to the technical field of heat-conducting insulating materials, and discloses a functional BN-rGO in-situ polymerization polyurethane heat-conducting insulating material, wherein a plurality of folds are formed by mutually overlapping reduction graphene oxide sheets, a BN-rGO composite material is obtained by ultrasonic treatment, the BN sheets form a continuous three-dimensional network structure, the interface thermal resistance between the composite materials is reduced, an excellent three-dimensional heat-conducting network is constructed for the polyurethane composite material, the BN cuts off the electron transmission between rGO and ensures the good electrical insulating property of the composite material, in Tris buffer solution, dopamine undergoes self-polymerization to form polydopamine which reacts with the BN-rGO composite material to obtain the functional BN-rGO modified by the polydopamine, and then polytetrahydrofuran diol and diphenylmethane diisocyanate are used as raw materials to obtain the functional BN-rGO in-situ polymerization polyurethane heat-conducting insulating material, the dispersibility and compatibility of BN-rGO in polyurethane are improved, so that the polyurethane has excellent thermal conductivity and insulating property.)
1. A functional BN-rGO in-situ polymerization polyurethane heat-conducting insulating material is characterized in that: the preparation method of the functional BN-rGO in-situ polymerization polyurethane heat-conducting insulating material comprises the following steps:
(1) adding graphite oxide into the crucible, then placing the crucible into a flange tube for sealing, introducing nitrogen at room temperature for 10-20min, preheating the tube furnace to 780-doped 820 ℃, placing the flange into the tube furnace for heat preservation for 8-12min, and cooling to obtain reduced graphene oxide;
(2) adding deionized water, reduced graphene oxide and boron nitride into a beaker, carrying out ultrasonic treatment for 1-3h to disperse uniformly, washing, filtering, and freeze-drying to obtain a BN-rGO composite material;
(3) adding deionized water and a BN-rGO composite material into a beaker, performing ultrasonic dispersion for 30-90min, adding a Tris buffer solution, performing ultrasonic dispersion uniformly, adding a 5% hydrochloric acid solution to adjust the pH value to 8.5, adding dopamine, performing magnetic stirring for 18-30h at room temperature, centrifuging, washing and drying to obtain a polydopamine modified functionalized BN-rGO;
(4) adding polytetrahydrofuran diol and 2, 2-dimethylolpropionic acid into a beaker, stirring for 15-25min in a 70-90 ℃ water bath, adding diphenylmethane diisocyanate and dibutyltin dilaurate serving as a catalyst, continuously stirring for 2-4h in a 75-85 ℃ water bath, then cooling to 40-50 ℃, adding triethylamine, stirring at a high speed, adding deionized water and poly dopamine modified functional BN-rGO, emulsifying for 20-40min, adding a small molecular chain extender 1, 4-butanediol, reacting for 30-60min, transferring into a conical flask, removing bubbles in vacuum, pouring into a mold, standing at normal temperature, and drying to obtain the functional BN-rGO in-situ polymerized polyurethane heat-conducting insulating material.
2. The functionalized BN-rGO in-situ polymerization polyurethane thermal conductive and insulating material as claimed in claim 1, wherein: the tubular furnace comprises a main body, a furnace tube is movably connected to the top of the main body in the step (1), an end cover is movably connected to the right side of the furnace tube, an air hole is movably connected to the right side of the end cover, a base is movably connected to the bottom of the main body, a motor is movably connected to the top of the base, a driving wheel is movably connected to the right side of the motor, a connecting rod is movably connected to the right side of the main body, a driven wheel is movably connected to the middle of the connecting rod, a combustor is movably connected to the left side of.
3. The functionalized BN-rGO in-situ polymerization polyurethane thermal conductive and insulating material as claimed in claim 1, wherein: the mass ratio of the reduced graphene oxide to the boron nitride in the step (2) is 1.5-2: 100.
4. The functionalized BN-rGO in-situ polymerization polyurethane thermal conductive and insulating material as claimed in claim 1, wherein: in the step (3), the mass ratio of the BN-rGO composite material to the dopamine is 100: 25-35.
5. The functionalized BN-rGO in-situ polymerization polyurethane thermal conductive and insulating material as claimed in claim 1, wherein: in the step (4), the mass ratio of polytetrahydrofuran diol, 2-dimethylolpropionic acid, diphenylmethane diisocyanate, dibutyltin dilaurate, triethylamine, polydopamine-modified functional BN-rGO to 1, 4-butanediol is 100:12-15:70-80:0.1-0.5:8-12:25-45: 3-6.
Technical Field
The invention relates to the technical field of heat-conducting insulating materials, in particular to a functional BN-rGO in-situ polymerization polyurethane heat-conducting insulating material and a preparation method thereof.
Background
In recent years, with the development and the maturation of the electronic industry, the size of internal devices of electronic equipment tends to be miniaturized, and the density of the devices in a unit volume is higher and higher, so that the temperature of the internal environment of the equipment is increased when the equipment works, and heat is rapidly accumulated when the temperature is reached, therefore, the heat dissipation performance of the electronic device is very important for the safe and stable operation of the whole system, and a heat-conducting and insulating composite material needs to be prepared, so that the heat of the electronic device can be rapidly transferred.
The waterborne polyurethane is a novel polyurethane system which takes water as a dispersing medium instead of an organic solvent, has the advantages of no toxicity, no combustion, good safety, no pollution and the like, and is widely applied to the fields of coatings, adhesives and the like, but the waterborne polyurethane has poor heat conductivity and insulation, the waterborne polyurethane needs to be subjected to chemical modification treatment, so that the waterborne polyurethane has excellent heat conductivity and insulation, the graphene has ultrahigh heat conductivity, and the boron nitride not only has excellent heat conductivity, but also has good insulation, so that the problems are solved by adopting a functional BN-rGO in-situ polymerization polyurethane mode.
Technical problem to be solved
Aiming at the defects of the prior art, the invention provides a functional BN-rGO in-situ polymerization polyurethane heat-conducting insulating material and a preparation method thereof, and solves the problems of poor heat conductivity and poor insulativity of polyurethane.
(II) technical scheme
In order to achieve the purpose, the invention provides the following technical scheme: a functional BN-rGO in-situ polymerization polyurethane heat-conducting and insulating material is prepared by the following steps:
(1) adding graphite oxide into the crucible, then placing the crucible into a flange tube for sealing, introducing nitrogen at room temperature for 10-20min, preheating the tube furnace to 780-doped 820 ℃, placing the flange into the tube furnace for heat preservation for 8-12min, and cooling to obtain reduced graphene oxide;
(2) adding deionized water, reduced graphene oxide and boron nitride into a beaker, carrying out ultrasonic treatment for 1-3h to disperse uniformly, washing, filtering, and freeze-drying to obtain a BN-rGO composite material;
(3) adding deionized water and a BN-rGO composite material into a beaker, performing ultrasonic dispersion for 30-90min, adding a Tris buffer solution, performing ultrasonic dispersion uniformly, adding a 5% hydrochloric acid solution to adjust the pH value to 8.5, adding dopamine, performing magnetic stirring for 18-30h at room temperature, centrifuging, washing and drying to obtain a polydopamine modified functionalized BN-rGO;
(4) adding polytetrahydrofuran diol and 2, 2-dimethylolpropionic acid into a beaker, stirring for 15-25min in a 70-90 ℃ water bath, adding diphenylmethane diisocyanate and dibutyltin dilaurate serving as a catalyst, continuously stirring for 2-4h in a 75-85 ℃ water bath, then cooling to 40-50 ℃, adding triethylamine, stirring at a high speed, adding deionized water and poly dopamine modified functional BN-rGO, emulsifying for 20-40min, adding a small
Preferably, the tubular furnace includes the main part in step (1), and the top swing joint of main part has the boiler tube, and the right side swing joint of boiler tube has the end cover, and the right side swing joint of end cover has the gas pocket, and the bottom swing joint of main part has the base, and the top swing joint of base has the motor, and the right side swing joint of motor has the action wheel, and the right side swing joint of main part has the connecting rod, and the centre swing joint of connecting rod has the follower, and the left side swing joint of connecting rod has the combustor, and the left side swing joint of combustor.
Preferably, the mass ratio of the reduced graphene oxide to the boron nitride in the step (2) is 1.5-2: 100.
Preferably, the mass ratio of the BN-rGO composite material to the dopamine in the step (3) is 100: 25-35.
Preferably, in the step (4), the mass ratio of the polytetrahydrofuran diol, the 2, 2-dimethylolpropionic acid, the diphenylmethane diisocyanate, the dibutyltin dilaurate, the triethylamine, the polydopamine modified functional BN-rGO and the 1, 4-butanediol is 100:12-15:70-80:0.1-0.5:8-12:25-45: 3-6.
(III) advantageous technical effects
Compared with the prior art, the invention has the following beneficial technical effects:
the functionalized BN-rGO in-situ polymerization polyurethane heat-conducting insulating material is subjected to high-temperature thermal reduction to obtain reduced graphene oxide, the lamellar layers of the reduced graphene oxide are mutually overlapped to form a large number of folds, the specific surface area is increased, the BN-rGO composite material is uniformly dispersed by ultrasonic waves, the rGO and the BN are bridged, the rGO has an ultra-large aspect ratio, the contribution of a size effect to ion scattering is reduced, the ultra-high specific surface area increases the contact area between the composite materials, the lap joint rate between the composite materials is improved, the BN lamellar layers are mutually overlapped to form a continuous three-dimensional porous net structure, the interface thermal resistance between the composite materials is reduced, an excellent three-dimensional heat-conducting network is constructed for the polyurethane composite material, an effective heat-conducting path can be formed only when the content of a single material is high, and the continuity of the heat-conducting network can be ensured when the content of the composite material is low, meanwhile, BN cuts off electron transmission among rGO, inhibits graphene from forming a conductive network and ensures good electrical insulation performance of the composite material.
The functional BN-rGO in-situ polymerization polyurethane heat-conducting insulating material is characterized in that dopamine is subjected to self-polymerization to form polydopamine in a Tris buffer solution, the polydopamine and a BN-rGO composite material are subjected to chemical reaction to obtain polydopamine modified functional BN-rGO, amino is introduced to enhance the interface bonding force between the composite material and a matrix and improve the overall thermal stability of the composite material and the matrix, polytetrahydrofuran diol and diphenylmethane diisocyanate are used as raw materials, dibutyltin dilaurate is used as a catalyst, triethylamine is used for adjusting the pH value of a solution, deionized water is used for adjusting the viscosity of the solution, 2-dimethylolpropionic acid is used for improving the water-based property of polyurethane to obtain the functional BN-rGO in-situ polymerization polyurethane heat-conducting insulating material, hydrogen bond association is generated between the amino group and hydroxyl group of the polydopamine modified functional BN-rGO and the urethane bond and urea bond of a water-based polyurethane hard segment, the interaction between the poly-dopamine modified functional BN-rGO and the hard segment of the waterborne polyurethane is large, so that the dispersibility and compatibility of the poly-dopamine modified functional BN-rGO in the waterborne polyurethane are improved, and the polyurethane has excellent thermal conductivity and insulativity.
Drawings
FIG. 1 is a schematic sectional elevational view of a tube furnace;
FIG. 2 is a schematic side view of a tube furnace.
1. A main body; 2. a furnace tube; 3. an end cap; 4. air holes; 5. a base; 6. a motor; 7. a driving wheel; 8. a connecting rod; 9. a driven wheel; 10. a burner; 11. and (4) a nozzle.
Detailed Description
To achieve the above object, the present invention provides the following embodiments and examples: a functional BN-rGO in-situ polymerization polyurethane heat-conducting and insulating material is prepared by the following steps:
(1) adding graphite oxide into a crucible, placing the crucible into a flange pipe for sealing, introducing nitrogen at room temperature for 10-20min, preheating the tubular furnace to 780-doped 820 ℃, placing the flange into the tubular furnace for heat preservation for 8-12min, wherein the tubular furnace comprises a main body, the top of the main body is movably connected with a furnace pipe, the right side of the furnace pipe is movably connected with an end cover, the right side of the end cover is movably connected with an air hole, the bottom of the main body is movably connected with a base, the top of the base is movably connected with a motor, the right side of the motor is movably connected with a driving wheel, the right side of the main body is movably connected with a connecting rod, the middle of the connecting rod is movably connected with a driven wheel, the left side of the connecting rod is movably connected with;
(2) adding deionized water, reduced graphene oxide and boron nitride into a beaker in a mass ratio of 1.5-2:100, performing ultrasonic treatment for 1-3h to disperse uniformly, washing, filtering, and freeze-drying to obtain a BN-rGO composite material;
(3) adding deionized water and a BN-rGO composite material into a beaker, performing ultrasonic dispersion for 30-90min, adding a Tris buffer solution, performing ultrasonic dispersion uniformly, adding a 5% hydrochloric acid solution to adjust the pH value to 8.5, and adding dopamine, wherein the mass ratio of the BN-rGO composite material to the dopamine is 100:25-35, performing magnetic stirring at room temperature for 18-30h, centrifuging, washing and drying to obtain the poly-dopamine modified functionalized BN-rGO;
(4) adding polytetrahydrofuran diol and 2, 2-dimethylolpropionic acid into a beaker, stirring for 15-25min in a water bath at 70-90 ℃, adding diphenylmethane diisocyanate and dibutyltin dilaurate serving as a catalyst, continuously stirring for 2-4h in a water bath at 75-85 ℃, then cooling to 40-50 ℃, adding triethylamine, stirring at a high speed, adding deionized water and the functional BN-rGO modified by polydopamine, emulsifying for 20-40min, and adding a small-