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CN-122011718-A - Shape memory nanocomposite with high thermal conductivity and preparation method and application thereof

CN122011718ACN 122011718 ACN122011718 ACN 122011718ACN-122011718-A

Abstract

The invention relates to a high-thermal conductivity shape memory nano composite material and a preparation method and application thereof, wherein the preparation method comprises the steps of utilizing phenylphosphonic acid to functionalize graphene nano sheets to obtain PPA@GNPs; under the environment with pH of 6-8, combining cellulose nanocrystals with PPA@GNPs through non-covalent interaction to form CNC-PPA@GNPs nanosheets, uniformly dispersing the CNC-PPA@GNPs nanosheets in a polypropylene carbonate PPC solution, and then carrying out tape casting coating and drying to obtain the high-thermal conductivity shape memory nanocomposite. The CNC anchored PPA functionalized graphene nanosheets GNPs form CNC-PPA@GNPs nanosheets, and the nanosheets are dispersed in a polypropylene carbonate PPC matrix to prepare the composite material through a solution casting method. According to the invention, the bridge heat conduction network is constructed in the PPC through the CNC-PPA@GNPs nanosheets, so that the heat conductivity, mechanical property and shape memory function of the composite material are remarkably improved, meanwhile, the composite material has biodegradability, the temperature of a CPU (Central processing Unit) of the smart phone can be reduced by 17.9 ℃ under the real operation condition, and the balance of heat insulation and heat dissipation is realized.

Inventors

  • YU HOUYONG
  • LIU YUHENG
  • Abdkrim Somiya Yasin Hossein

Assignees

  • 浙江理工大学

Dates

Publication Date
20260512
Application Date
20260209

Claims (10)

  1. 1. The preparation method of the shape memory nanocomposite with high thermal conductivity is characterized by comprising the following steps: (1) The PPA functionalized graphene nano-sheets GNPs are utilized to obtain PPA@GNPs; (2) Combining cellulose nanocrystalline CNC and PPA@GNPs through non-covalent interaction in a pH 6-8 environment to form CNC-PPA@GNPs nanosheets; (3) Uniformly dispersing CNC-PPA@GNPs nano sheets in a polypropylene carbonate PPC solution, and then carrying out tape casting coating and drying to obtain the shape memory nano composite material with high thermal conductivity.
  2. 2. The preparation method according to claim 1, wherein in the step (1), PPA is dissolved in water, GNPs powder is added, and vacuum freeze drying is performed after ball milling treatment to obtain ppa@gnps; Wherein the rotation speed of ball milling treatment is 300-500 rpm, and the time is 24-72 hours.
  3. 3. The preparation method according to claim 2, wherein the mass ratio of PPA to GNPs powder is (3-5): 1.
  4. 4. The preparation method of claim 1, wherein in the step (2), CNC and PPA@GNPs are mixed in a dispersion medium with pH of 6-8, and the mixture is treated by an ultrasonic cell disruptor, and then centrifuged and the precipitate is collected and freeze-dried to obtain CNC-PPA@GNPs nanosheets; Wherein the power of the ultrasonic cell disruption instrument is 800-1200W, the pulse mode is opened for 5-10 s/closed for 5-10s, and the whole treatment process is carried out for 1-2 hours.
  5. 5. The preparation method according to claim 4, wherein the mass ratio of CNC to PPA@GNPs is 1 (0.5-1.5).
  6. 6. The method according to claim 1, wherein in the step (3), the solid-to-liquid ratio of the PPC solution is 1 (5-7), and the drying temperature is 60-80 ℃.
  7. 7. The high thermal conductivity shape memory nanocomposite produced by the method of any one of claims 1 to 6, wherein the mass fraction of CNC-ppa@gnps nanoplatelets in the high thermal conductivity shape memory nanocomposite is 1 to 10%.
  8. 8. The shape memory nanocomposite of claim 7, wherein the thermal conductivity is 1.81-3.2 w.m -1 ·K -1 , the shape retention Rf is greater than or equal to 90%, the shape recovery Rr is greater than or equal to 90%, and the recovery of deformation is completed within 30 seconds.
  9. 9. The high thermal conductivity shape memory nanocomposite of claim 7, wherein the biodegradation rate in soil for 120 days is 15-20%.
  10. 10. Use of a high thermal conductivity shape memory nanocomposite material according to any of claims 7-9 for heat dissipation or electronic packaging of a smart phone CPU in electronic device thermal management.

Description

Shape memory nanocomposite with high thermal conductivity and preparation method and application thereof Technical Field The invention belongs to the technical field of polymer composite materials, and particularly relates to a high-thermal-conductivity shape memory nanocomposite and a preparation method and application thereof, which are particularly suitable for thermal management, degradable packaging and shape memory materials of 5G electronic equipment. Background With the rapid development of 5G technology and miniaturization and high power of electronic devices, internal heat accumulation problems are increasingly prominent, resulting in reduced device stability, reduced efficiency and shortened lifetime. The traditional thermal management materials such as epoxy resin and polyimide film have the problems of non-biodegradability, easiness in causing electronic waste pollution and the like. Polypropylene carbonate PPC, a biodegradable polymer, has shape memory properties, but its inherent drawbacks such as low thermal conductivity (about 0.059w·m -1·K-1), low mechanical strength (tensile strength 5.7 MPa) and poor thermal stability (T max about 251.5 ℃) limit its use in high performance electronics. The graphene nano-sheets GNPs have high theoretical thermal conductivity (5000 W.m -1·K-1), are ideal fillers for enhancing the thermal performance of the polymer, but the GNPs are easy to agglomerate, so that interface defects and performance are reduced. Cellulose nanocrystalline CNC can be used as a bio-based reinforcing agent, and the dispersibility is improved through hydrogen bonds, but the problems of agglomeration of GNPs and interfacial compatibility cannot be effectively solved by the traditional method. Therefore, there is an urgent need in the art to develop a composite material having high thermal conductivity, mechanical strength, biodegradability and thermal stability. Disclosure of Invention Based on the defects in the prior art, the invention aims to provide a high-heat-conductivity shape memory nanocomposite, a preparation method and application thereof, CNC-PPA@GNPs nanosheets are formed by anchoring PPA functionalized GNPs through CNC, and a bridging heat conduction network is constructed in a PPC matrix, so that heat conductivity, mechanical performance and shape memory function are synergistically improved. In order to achieve the aim of the invention, the invention adopts the following technical scheme: a preparation method of a shape memory nanocomposite with high thermal conductivity comprises the following steps: (1) The PPA functionalized graphene nano-sheets GNPs are utilized to obtain PPA@GNPs; (2) Combining cellulose nanocrystalline CNC and PPA@GNPs through non-covalent interactions (such as hydrogen bonds and pi-pi stacking) in an environment with pH of 6-8 to form CNC-PPA@GNPs nanosheets; (3) Uniformly dispersing CNC-PPA@GNPs nano sheets in a polypropylene carbonate PPC solution, and then carrying out tape casting coating and drying to obtain the shape memory nano composite material with high thermal conductivity. In the step (1), PPA is dissolved in water, GNPs powder is added, and vacuum freeze drying is carried out after ball milling treatment to obtain PPA@GNPs; wherein the rotation speed of ball milling treatment is 300-500 rpm, and the time is 24-72 hours; the ball milling ensures that PPA uniformly modifies the surface of GNPs through pi-pi accumulation and Van der Waals force to inhibit agglomeration. Preferably, the mass ratio of PPA to GNPs powder is (3-5): 1. In the step (2), CNC and PPA@GNPs are mixed in a dispersion medium with pH of 6-8, and are placed in an ultrasonic cell disruption instrument for treatment, and then the precipitate is centrifuged and collected for freeze drying, so that CNC-PPA@GNPs nanosheets are obtained; Wherein the power of the ultrasonic cell disruption instrument is 800-1200W, the pulse mode is opened for 5-10 s/closed for 5-10s, and the whole treatment process is carried out for 1-2 hours. Preferably, the mass ratio of CNC to PPA@GNPs is 1 (0.5-1.5). At this mass ratio, the hydroxyl groups of CNCs form a hydrogen bond network with the phosphoryl groups of PPA (p=o), while the steric hindrance effect of CNCs effectively prevents GNPs from aggregating. Preferably, in the step (3), the solid-to-liquid ratio of the PPC solution is 1 (5-7), and the drying temperature is 60-80 ℃. The invention also provides the high-thermal conductivity shape memory nanocomposite prepared by the preparation method according to any one of the schemes, wherein the mass fraction of CNC-PPA@GNPs nano sheets in the high-thermal conductivity shape memory nanocomposite is 1-10%. As a preferable scheme, the high-thermal-conductivity shape memory nanocomposite has thermal conductivity of 1.81-3.2 W.m -1·K-1, the shape fixing rate Rf is more than or equal to 90%, the shape recovery rate Rr is more than or equal to 90%, and the deformation recovery is completed within