阅读说明：本技术 一种具有热响应性能的高导热高分子材料复合膜及其制备方法 (High-thermal-conductivity high-polymer material composite membrane with thermal response performance and preparation method thereof ) 是由 丁鹏 彭方 宋娜 于 2021-01-19 设计创作，主要内容包括：本发明公开了一种具有热响应性能的高导热高分子材料复合膜,其为一种多层结构复合膜,其由以下重量百分比的组分制成：石墨烯0～20％,氮化硼0～20％,纳米纤维素30～40％,聚乙二醇30～40％。本发明还公开了其制备方法,其包括如下步骤:分别将各组分加入分散剂中制得分散液；然后搅拌、超声得到混合液；将混合液脱气后倒入模具中进一步干燥,分别制得纳米纤维素-聚乙二醇复合膜等多个单层膜。本发明通过对填料量进行优化设计和宏观调整不同层的位置,将各单层膜按照设定的次序堆叠在一起后热压,得到一种导热层与基体层交替排列的具有多层结构的复合膜,该复合薄膜具有良好的柔韧性、高的面内导热率及热驱动形状记忆性能。(The invention discloses a high-thermal-conductivity high polymer material composite film with thermal response performance, which is a multilayer structure composite film and is prepared from the following components in percentage by weight: 0-20% of graphene, 0-20% of boron nitride, 30-40% of nanocellulose and 30-40% of polyethylene glycol. The invention also discloses a preparation method thereof, which comprises the following steps of respectively adding each component into a dispersant to prepare dispersion liquid; then stirring and carrying out ultrasonic treatment to obtain a mixed solution; and degassing the mixed solution, pouring the degassed mixed solution into a mold for further drying, and respectively preparing a plurality of single-layer films such as the nano cellulose-polyethylene glycol composite film. According to the invention, through carrying out optimization design on the amount of the filler and macroscopically adjusting the positions of different layers, the single-layer films are stacked together according to a set sequence and then are subjected to hot pressing, so that the composite film with the multilayer structure, in which the heat conduction layers and the substrate layer are alternately arranged, is obtained, and the composite film has good flexibility, high in-plane heat conductivity and heat-driven shape memory performance.)

1. A high heat conduction high polymer material composite film with thermal response performance is characterized in that the composite film is a multilayer composite film with high heat conduction performance and thermal drive shape memory performance, and is prepared from the following components in percentage by weight: 0-20% of graphene, 0-20% of boron nitride, 30-40% of nanocellulose and 30-40% of polyethylene glycol.

2. The high thermal conductive polymer material composite film according to claim 1, wherein the average horizontal size of the graphene is 10 to 20 μm, and the average thickness is 5 to 10 layers.

3. The high thermal conductivity polymer composite film according to claim 1, wherein the average size of the boron nitride is 3 to 5 μm.

4. The high thermal conductive polymer composite film with thermal response property as claimed in claim 1, wherein the diameter of the nano-cellulose is 5-100nm, the length-diameter ratio is 100-1000; the molecular weight of polyethylene glycol is 6000 to 10000.

5. The method for preparing the high thermal conductive polymer material composite film with thermal response performance according to claims 1 to 4, characterized by comprising the following steps:

(1) respectively adding boron nitride, graphene, nano-cellulose and polyethylene glycol into a dispersing agent, stirring for 0.5-l h, performing ultrasonic treatment for 5-10min, and preparing a boron nitride dispersion liquid, a graphene dispersion liquid, a nano-cellulose dispersion liquid and a polyethylene glycol dispersion liquid with the concentration of 1-5 mg/mL;

(2) mixing the boron nitride dispersion liquid, the graphene dispersion liquid, the nano-cellulose dispersion liquid and the polyethylene glycol dispersion liquid obtained in the step (1) according to a set weight ratio, stirring for 0.5-l h, and performing ultrasonic treatment for 5-10min to obtain a boron nitride-nano-cellulose-polyethylene glycol mixed liquid, a graphene-nano-cellulose-polyethylene glycol mixed liquid and a graphene/boron nitride-nano-cellulose-polyethylene glycol mixed liquid with concentrations of 5-10 mg/mL;

(3) mixing the nano-cellulose dispersion liquid and the polyethylene glycol dispersion liquid according to a set proportion to obtain a nano-cellulose-polyethylene glycol mixed liquid, respectively placing the mixed liquid and the three mixed liquids obtained in the step (2) into a vacuum drying oven, standing for 0.5-lh at room temperature in a vacuum environment, and removing gas existing in the mixed liquid;

(4) pouring the three mixed solutions obtained in the step (2) and the nano-cellulose-polyethylene glycol mixed solution obtained in the step (3) into a mold, and placing the mold in an oven at 40-50 ℃ for drying for 6-10 hours to obtain a nano-cellulose-polyethylene glycol composite membrane (P), a graphene-nano-cellulose-polyethylene glycol composite membrane (G), a boron nitride-nano-cellulose-polyethylene glycol composite membrane (B) and a graphene/boron nitride-nano-cellulose-polyethylene glycol composite membrane (U-GB);

(5) and (4) repeating the step (4) for multiple times to obtain a plurality of single-layer films, stacking the single-layer composite films together according to a set sequence, and then carrying out hot pressing to obtain the multilayer high-thermal-conductivity graphene-boron nitride-high polymer material composite film with the thermal driving shape memory characteristic.

6. The method of claim 5, wherein the dispersant is one or more of deionized water, cyclohexane, ethanol, and N, N-dimethylformamide.

Technical Field

The invention relates to a functional polymer composite material, belongs to the field of heat-conducting polymer composite materials and shape memory polymer composite materials, and particularly relates to a thermally-driven shape memory multilayer high-heat-conducting polymer material composite film and a preparation method thereof.

Background

Shape Memory Material (SMM) is a stimulus-responsive material that has received much attention for its unique shape memory properties. It can sense the external environment change (such as temperature, electricity, light, magnetism, pH, etc.), and respond to the change, and the temporary shape returns to the original shape. Compared with SMM (such as shape memory alloy, shape memory ceramic and the like), Shape Memory Polymer (SMP) has the advantages of large shape recovery rate, low response temperature, low cost, excellent processing and forming performance, easy modification and the like, so the SMP has very wide application prospect in the fields of biomedicine, electronic information, intelligent devices and the like.

The graphene is a two-dimensional-carbon nano material with a series of excellent performances such as high specific surface area, excellent mechanical property and conductivity. It is noteworthy that graphene has the highest thermal conductivity known at present, and the theoretical thermal conductivity at room temperature can reach 5300 W.m^-1·K^-1. Therefore, the heat conducting performance of the high polymer material can be improved and other characteristics of the high polymer material can be reserved by adding the heat conducting agent into the high polymer material.

The hexagonal boron nitride is a two-dimensional nano material with a series of excellent performances such as excellent high-temperature stability, high strength, high thermal conductivity coefficient, high resistivity and the like. Therefore, when the heat-conducting resin is added into the high polymer material, the heat-conducting property of the high polymer material can be obviously improved, the electric insulation property of the high polymer material can be improved, and the application range of the high polymer composite material is expanded.

The cellulose material is a natural polymer material, has the performances of transparent, light, high-strength and other polymer materials, and has the characteristics of good biocompatibility, wide sources, reproducibility, degradability and the like. Meanwhile, the surface of the nano-cellulose has rich oxygen-containing functional groups, and good conditions are provided for the interaction of the nano-cellulose with other high polymer materials and inorganic fillers. Thus, nanocellulose may be used to enhance the mechanical properties of the composite.

In the prior art, the shape memory material has the capability of generating shape change under external stimulation and is an intelligent material. The shape memory polymer material has the characteristics of light weight, low price, chemical corrosion resistance and easy processing. Compared with shape memory alloy, the shape memory polymer material has the advantages of high shape recovery rate, wide memory recovery temperature and the like. However, the existing shape memory materials generally have the problems of high raw material cost, complex manufacturing process, large shape memory performance difference and the like, and generally only have one response shape memory characteristic, so that the use scene is greatly limited.

Disclosure of Invention

In view of the above disadvantages of the prior art, an object of the present invention is to provide a multilayer high thermal conductivity polymer composite film capable of realizing thermally driven shape memory and a method for preparing the same, wherein the filling amount and structure of the material are synchronously optimized, so that the composite film has good flexibility, high transverse thermal conductivity and thermally driven shape memory performance; meanwhile, the preparation method is improved, the process is simplified, and the overall manufacturing cost is reduced, so that the method is beneficial to industrial popularization and application.

In order to achieve the purpose, the invention provides the following technical scheme:

a high heat conduction high polymer material composite film with thermal response performance is characterized in that the composite film is a multilayer composite film with high heat conduction performance and thermal drive shape memory performance, and is prepared from the following components in percentage by weight: 0-20% of graphene, 0-20% of boron nitride, 30-40% of nanocellulose and 30-40% of polyethylene glycol.

Wherein the average horizontal size of the graphene is 10-20 microns, and the average thickness of the graphene is 5-10 layers; the average size of the boron nitride is 3-5 microns. The diameter of the nano-cellulose is 5-100nm, and the length-diameter ratio is 100-1000; the molecular weight of polyethylene glycol is 6000 to 10000.

The preparation method of the high-thermal-conductivity polymer material composite film with the thermal response performance is characterized by comprising the following steps of:

(1) respectively adding boron nitride, graphene, nano-cellulose and polyethylene glycol into a dispersing agent, stirring for 0.5-1 h, performing ultrasonic treatment for 5-10min, and preparing a boron nitride dispersion liquid, a graphene dispersion liquid, a nano-cellulose dispersion liquid and a polyethylene glycol dispersion liquid with the concentration of 1-5 mg/mL;

(2) mixing the boron nitride dispersion liquid, the graphene dispersion liquid, the nano-cellulose dispersion liquid and the polyethylene glycol dispersion liquid obtained in the step (1) according to a set weight ratio, stirring for 0.5-1 h, and performing ultrasonic treatment for 5-10min to obtain a boron nitride-nano-cellulose-polyethylene glycol mixed liquid, a graphene-nano-cellulose-polyethylene glycol mixed liquid and a graphene/boron nitride-nano-cellulose-polyethylene glycol mixed liquid with concentrations of 5-10 mg/mL;

(3) mixing the nano-cellulose dispersion liquid and the polyethylene glycol dispersion liquid according to a set proportion to obtain a nano-cellulose-polyethylene glycol mixed liquid, respectively placing the mixed liquid and the three mixed liquids obtained in the step (2) in a vacuum drying oven, standing for 0.5-1 h in a vacuum environment at room temperature, and removing gas existing in the mixed liquid;

(4) pouring the three mixed solutions obtained in the step (2) and the nano-cellulose-polyethylene glycol mixed solution obtained in the step (3) into a mold, and placing the mold in an oven at 40-50 ℃ for drying for 6-10 hours to obtain a nano-cellulose-polyethylene glycol composite membrane (P), a graphene-nano-cellulose-polyethylene glycol composite membrane (G), a boron nitride-nano-cellulose-polyethylene glycol composite membrane (B) and a graphene/boron nitride-nano-cellulose-polyethylene glycol composite membrane (U-GB);

(5) and (4) repeating the step (4) for multiple times to obtain a plurality of single-layer films, stacking the single-layer composite films together according to a set sequence, and then carrying out hot pressing to obtain the multilayer high-thermal-conductivity graphene-boron nitride-high polymer material composite film with the thermal driving shape memory characteristic.

In the preparation method, the dispersant is one or more of deionized water, cyclohexane, ethanol and N, N-dimethylformamide solvent.

The invention has the beneficial effects that:

(1) the high-thermal-conductivity high-polymer material composite film with the thermal response performance is reasonable in formula, low in material cost, and has the thermally-driven shape memory characteristic of 50-70 ℃, and the material has a permanent shape and a temporary shape; therefore, compared with the traditional high polymer material, the shape memory high polymer material can realize more set functional actions, thereby further improving the application range of the material.

(2) The high-thermal-conductivity high-molecular-material composite membrane with the thermal response performance has high in-plane thermal conductivity, and the material has more complex and unique functions by combining the thermal driving shape memory characteristic of the composite membrane, so that the composite membrane is more widely applied.

(3) According to the invention, the weight ratio of each component such as graphene and boron nitride in the high polymer material is optimally designed, and the structure of the multilayer film is macroscopically regulated and controlled, so that the multilayer film can obtain higher thermal conductivity, meanwhile, the two heat-conducting fillers are synergistically promoted, so that the thermal conductivity of the multilayer film is greatly improved, and the composite film has good flexibility by adding the nano-cellulose as a reinforcing phase.

(4) The high-thermal-conductivity high-molecular-material composite membrane with the thermal response performance provided by the invention has the advantages of compact preparation process, easiness in control, low equipment requirement, simplicity in operation method, high adjustability, easiness in obtaining raw materials, low overall manufacturing cost and easiness in industrial application and popularization. The shape memory polymer material provided by the invention has a huge application prospect in the fields of sensors, aerospace and the like.

The foregoing is a summary of the technical solutions of the present invention, and the present invention is further described below with reference to specific embodiments.

Drawings

FIG. 1 is a cross-sectional electron microscope of a high thermal conductivity polymer composite film according to an embodiment of the present invention;

fig. 2 is a surface electron microscope image of the high thermal conductive polymer composite film according to the embodiment of the invention.

Detailed Description

The technical solution of the present invention is further described in detail with reference to the following examples, but the scope of the present invention is not limited thereto.

Referring to the attached drawings 1-2, the high thermal conductivity polymer material composite film with thermal response performance provided by the embodiment of the invention is characterized in that the composite film is a multilayer composite film with high thermal conductivity and thermal drive shape memory performance, and is prepared from the following components in percentage by weight: 0-20% of graphene, 0-20% of boron nitride, 30-40% of nanocellulose and 30-40% of polyethylene glycol.

Wherein the average horizontal size of the graphene is 10-20 microns, and the average thickness of the graphene is 5-10 layers; the average size of the boron nitride is 3-5 microns. The diameter of the nano-cellulose is 5-100nm, and the length-diameter ratio is 100-1000; the molecular weight of polyethylene glycol is 6000 to 10000.

The preparation method of the high-thermal-conductivity polymer material composite film with the thermal response performance is characterized by comprising the following steps of:

(1) respectively adding boron nitride, graphene, nano-cellulose and polyethylene glycol into a dispersing agent, stirring for 0.5-1 h, performing ultrasonic treatment for 5-10min, and preparing a boron nitride dispersion liquid, a graphene dispersion liquid, a nano-cellulose dispersion liquid and a polyethylene glycol dispersion liquid with the concentration of 1-5 mg/mL;

(2) mixing the boron nitride dispersion liquid, the graphene dispersion liquid, the nano-cellulose dispersion liquid and the polyethylene glycol dispersion liquid obtained in the step (1) according to a set weight ratio, stirring for 0.5-1 h, and performing ultrasonic treatment for 5-10min to obtain a boron nitride-nano-cellulose-polyethylene glycol mixed liquid, a graphene-nano-cellulose-polyethylene glycol mixed liquid and a graphene/boron nitride-nano-cellulose-polyethylene glycol mixed liquid with concentrations of 5-10 mg/mL;

(3) mixing the nano-cellulose dispersion liquid and the polyethylene glycol dispersion liquid according to a set proportion to obtain a nano-cellulose-polyethylene glycol mixed liquid, respectively placing the mixed liquid and the three mixed liquids obtained in the step (2) in a vacuum drying oven, standing for 0.5-1 h in a vacuum environment at room temperature, and removing gas existing in the mixed liquid;

(4) pouring the three mixed solutions obtained in the step (2) and the nano-cellulose-polyethylene glycol mixed solution obtained in the step (3) into a mold, and placing the mold in an oven at 40-50 ℃ for drying for 6-10h to respectively obtain a nano-cellulose-polyethylene glycol composite membrane (P), a graphene-nano-cellulose-polyethylene glycol composite membrane (G), a boron nitride-nano-cellulose-polyethylene glycol composite membrane (B) and a graphene/boron nitride-nano-cellulose-polyethylene glycol composite membrane (U-GB);

(5) and (4) repeating the step (4) for multiple times to obtain a plurality of single-layer films, stacking the single-layer composite films together according to a set sequence, and then performing hot pressing to obtain the multilayer high-thermal-conductivity graphene-boron nitride-high polymer material composite film with the thermal driving shape memory characteristic.

In the preparation method, the dispersant is one or more of deionized water, cyclohexane, ethanol and N, N-dimethylformamide solvent.

Detailed description of the preferred embodiment 1

The high thermal conductive polymer material composite film with thermal response performance provided by the embodiment is a multilayer high thermal conductive polymer material composite film with thermal drive shape memory performance, and is composed of graphene, boron nitride, polyethylene glycol and nanocellulose, wherein the mass percent of graphene in the composite film is 19%, the mass percent of boron nitride is 1%, the mass percent of nanocellulose is 40%, and the mass percent of polyethylene glycol is 40%. Wherein the average horizontal size of the graphene is 10-20 microns, and the average thickness of the graphene is 5-10 layers; the average size of the boron nitride is 3-5 microns. The diameter of the nano-cellulose is 5-100nm, and the length-diameter ratio is 100-1000; the molecular weight of polyethylene glycol is 10000.

The preparation method of the multilayer high-thermal-conductivity polymer material composite film with thermally-driven shape memory provided by the embodiment comprises the following steps:

(1) adding graphene and boron nitride into deionized water, stirring for 0.5-1 h, performing ultrasonic treatment for 5-10min, and respectively preparing a graphene dispersion liquid and a boron nitride dispersion liquid with the concentration of 1-5 mg/mL;

(2) adding the nano-cellulose into deionized water, stirring for 0.5-1 h, performing ultrasonic treatment for 5-10min, and preparing a nano-cellulose dispersion solution with the concentration of 1-5 mg/mL;

(3) adding polyethylene glycol into deionized water, stirring for 0.5-1 h, performing ultrasonic treatment for 5-10min, and preparing a polyethylene glycol dispersion solution with the concentration of 1-5 mg/mL;

(4) mixing the graphene dispersion liquid and the boron nitride dispersion liquid obtained in the step (1), the nano-cellulose dispersion liquid obtained in the step (2) and the polyethylene glycol dispersion liquid obtained in the step (3) according to a set weight ratio, stirring for 1h, and performing ultrasonic treatment for 10min to obtain a graphene-nano-cellulose-polyethylene glycol mixed liquid and a boron nitride-nano-cellulose-polyethylene glycol mixed liquid;

(5) mixing the nano-cellulose dispersion liquid obtained in the step (2) and the polyethylene glycol dispersion liquid obtained in the step (3) according to the ratio of 1: mixing at a weight ratio of 1, stirring for 1h, and performing ultrasonic treatment for 10min to obtain a mixed solution of nano-cellulose and polyethylene glycol.

(6) Placing the graphene-nanocellulose-polyethylene glycol mixed solution, the boron nitride-nanocellulose-polyethylene glycol dispersion solution and the nanocellulose-polyethylene glycol mixed solution obtained in the steps (4) and (5) in a vacuum drying oven, standing in a vacuum environment at room temperature, and removing gas existing in the mixed solution;

(7) pouring the three dispersion solutions mentioned in the step (6) into different molds, placing the molds in an oven at 40 ℃ and drying the molds for 10 hours to obtain four corresponding single-layer heat-conducting composite films (a nanocellulose-polyethylene glycol composite film (P), a graphene-nanocellulose-polyethylene glycol composite film (G), a boron nitride-nanocellulose-polyethylene glycol composite film (B) and a graphene/boron nitride-nanocellulose-polyethylene glycol composite film (U-GB)); the four single-layer heat-conducting composite films are stacked together according to a set order and then are subjected to hot pressing, and the multilayer high-heat-conducting graphene-boron nitride-high polymer material composite film with the heat-driven shape memory characteristic is prepared.

The thermal conductivity of the multilayer high thermal conductivity polymer composite film with thermally driven shape memory prepared in the embodiment 1 was tested by using an LFA447 type laser thermal conductivity meter of germany Netzsch company, and the test results are as follows: transverse thermal conductivity of 53.76 W.m^-1·K^-1And the flexible heat conducting material has good flexibility, and the variation range of the heat conductivity coefficient after being bent by 200 degrees is 0-5 percent. The testing method of the shape memory performance comprises the steps of bending the composite film at 70 ℃ to form 90-degree bending deformation, fixing the temporary shape at room temperature, and raising the temperature to 70 ℃ again to record the recovery rate. The test results are: the shape recovery rate is more than 90% within 60s at 70 ℃.

The temperatures for memory use in this example were room temperature (20 ℃) and 70 ℃, which are the temperatures at which the memory effect was produced.

By optimally designing the mass ratio of graphene to boron nitride in the multi-layer U-GB film, the heat conduction value can be changed accordingly.

The components and the mixture ratio (mass percentage) of other examples are shown in the following table 1

The heat conduction value of the multilayer composite film with the heat conduction layers and the substrate layers arranged alternately can be changed correspondingly along with the change of the stacking sequence.

The components and proportions (in mass%) and stacking order of the other examples are given in table 2 below:

component name	Example 1	Example 2	Example 3	Example 4
					Graphene	19	19	19	19
Boron nitride	1	1	1	1
					Nano cellulose	40	40	40	40
Polyethylene glycol	40	40	40	40
					Stacking order	GPBPG	GPGPB	BPBPG	BPGPB
Heat conductivity value (W.m)-1·K-1)	53.76	38.71	23.2	24.59

In each embodiment of the invention and other embodiments, the specific component ratios of the components in the composite material can be selected according to specific requirements within the ranges of 0 wt% -20 wt% of graphene, 0 wt% -20 wt% of boron nitride, 30 wt% -40 wt% of nanocellulose and 30 wt% -40 wt% of polyethylene glycol, and the dispersant is one or more of deionized water, cyclohexane and other solvents, so that the technical effects can be achieved.

According to the invention, through the optimized design of the amount of the filler and the macroscopic adjustment of the positions of different layers, the single-layer films are stacked together according to a set sequence and then are subjected to hot pressing, so that the composite film with the multilayer structure, in which the heat conduction layers and the substrate layer are alternately arranged, is obtained, and the composite film has good flexibility, high in-plane thermal conductivity and heat-driven shape memory performance.

The invention is not limited to the above embodiments, and other multilayer high thermal conductivity polymer material composite films containing thermally-actuated shape memory, which are obtained by using the same or similar components, proportions and methods as those of the invention, are within the protection scope of the invention.