Preparation And Study Of Carbon Nanotubes/Polyimide Composite Films

Polyimides are well known as functional polymer materials with heat resistance, goodchemical stability, mechanical properties, low dielectric and radiation resistance. But electricalinsulation is becoming a big problem, which has become obstacles to its application in theaerospace field, it will lead to a universe of electrons and protons prone to charge theaccumulation of static electricity, aviation equipment likely to be destroyed. Therefore, we needto modify traditional polyimides.Since carbon nanotubes have been found, the carbon nanotubes as a new type ofone-dimensional functional materials are a great deal of attention in the scientific communityand industry, has become a hot area of scientific research. Carbon nanotubes with its excellentmechanical, electrical, thermal, optical and magnetic, to come to the fore in many materials.Growing number of scientists and doping in the polymer matrix, used to improve certainproperties of the polymer. The unique structure of carbon nanotubes, the carbon nanotubes isdifficult to be dispersed in a solvent, and the ability to be uniformly dispersed in the polymersolution to improve the performance of polymer has a great influence.Modification of carbon nanotubes is a good way to improve the carbon nanotube dispersionin the matrix, the modified method can be divided into covalent modification and non-covalentmodification, so this paper will be on carbon nanotubes covalently modified and non-pricemodification, and modification of carbon nanotubes by IR, Raman, transmission electronmicroscopy, elemental analysis, X-ray diffraction and thermal gravimetric analysis of a series ofcharacterization, to determine an effective modification of carbon nanotubes.Modificated carbon nanotubes as a modifier of the polyimide, expect to be able to improvethe electrical, mechanical, thermal properties and other aspects of performance of thepolyimide.In this thesis, polyimide was prepared by4,4’-ODA and PMDA from the traditional toreduce the cost of the experiment. At the same time by in situ polymerization, prepare covalentmodification of carbon nanotube/polyimide composite films and non-covalent modification ofcarbon nanotube/polyimide composite films. UV test light transmittance of the film in order toensure the films with optical transparency of the pure polyimide film, such film solar absorption is relatively low, the thermal emission rate will be higher, can not affect its aviation the field ofaerospace applications, to ensure that the films are good light is also crucial; infrared test toconfirm the successful polymerization of the polyimide; scanning electron microscopy, X-raydiffraction observation of microstructure of the films; dynamic mechanical analysis,thermogravimetric analysis, thermal, mechanical and electrical properties of the compositefilms after the stretching, electrical testing means testing of carbon nanotubes modified.