Preparation And Properties Of Multi-walled Carbon Nanotubes/Polyimide Composite Film

Due to the increasing development of electronic information technology,electronic products continue to prosper and change in the direction of miniaturization,multi-function and portability,and the development of electronic packaging materials has also entered a new research stage.The performance requirements of the new packaging materials mainly include excellent heat dissipation performance,stable thermal expansion coefficient,good mechanical properties,and excellent heat resistance.Among them,polyimide has many excellent properties,such as: excellent high temperature resistance,excellent mechanical properties and long life cycle,etc.,making it one of the best matrix materials in electronic packaging materials,but its lower the thermal conductivity and extremely poor electrical conductivity limit its wider application.Therefore,by introducing nano-fillers into the polyimide matrix and modifying the interface binding force,the performance between the polyimide and the nano-fillers can be compensated for each other,and their respective advantages can be fully utilized The defect of poor thermal conductivity of amine finally obtains a composite material with excellent comprehensive performance,which can make the nano-fillers/polyimide composite material suitable for electronic packaging materials in aerospace,microelectronics and other fields.In this paper,surface modification of carbon nanotubes was carried out to prepare carboxylated carbon nanotubes(MWCNTs-COOH),aminated carbon nanotubes(MWCNTs-ODA)and silver-modified aminated carbon nanotubes(MWCNTs-ODA/Ag).Diaminodiphenyl ether(ODA)and pyromellitic anhydride(PMDA)were used as raw materials to synthesize polyamic acid solution(PAA)by in-situ polymerization.Then,the carbon nanotubes with different functions are combined with the polyamic acid solution,and after the coating film and the thermal imidization process,the functionalized carbon nanotube/polyimide composite film is obtained.The structure,morphology and performance of the carbon nanotubes were characterized,and the test results showed that the introduction of carboxyl groups,amino groups,and silver nanoparticles in the carbon nanotubes did not affect the structure and performance of the carbon nanotubes.It is concluded through characterization that when the tensile strength of the pure PI film is 117.2 MPa and the content of the MWCNTs-ODA nano-filler is 3 wt%,the tensile strength of the MWCNTs-ODA/PI composite film is 141.5 MPa,which is The tensile strength is increased by 20.74%,and when the content of MWCNTs-ODA/Ag nano-filler is 3 wt%,the tensile strength of MWCNTs-ODA/Ag/PI composite film is 123.0 MPa,which is higher than that of pure PI film is 4.9%.When the thermal conductivity of pure PI film is 0.11 W/mK and the content of MWCNTs-ODA nanofiller is 3 wt%,the thermal conductivity of MWCNTs-ODA/PI composite film is 0.44 W/mK,which is higher than that of pure PI film.When the content of MWCNTs-ODA/Ag nano-filler is 3 wt%,the thermal conductivity of MWCNTs-ODA/Ag/PI composite film can reach 0.55 W/mK,which is 400.00% higher than that of pure PI film.