Preparation And Study Of Indium Tin Oxide/Polyimide Composite Films

Preparation and Study of Indium Tin Oxide/Polyimide Composite FilmsThe polyimide materials are widely used in the fields of aerospace,microelectronics, automobile and so on due to their considerable resistance to hightemperatures, high dimensional accuracy and high tolerance against radiation. But thehigh resistivity of the material limits its application. For example, if the spacecraftsurface material has high resistivity, it will enrich great amount of charge and difficultto disperse during its operation in the space. When the surface charge accumulated toa certain extent, the material surface discharge behavior occurs, this may causeproperty damage even scientific disaster. Modified polyimide material is necessary tobe studied to improve the conductivity of the material on the basis of maintaining theexcellent performance of the original material, so with a certain degree of antistaticability to better meet the requirements of the aerospace industry materials.ITO materials were discovered at the beginning of the last century, but were notattracted attention until the forties. Due to its excellent electrical properties andoptical properties, as well as the characteristics of blocking the infrared, ultravioletand electron radiation, often applied to the touchpad, construction of energy-savingglass, etc. in the form of transparent conductive films.In this thesis, we doped ITO micronized into polyimide to form a composite filmof the ITO/PI, which not only has the properties of high strength, high modulus, andexcellent thermal stability characteristics of polyimide but also has high opticalpermeability and conductivity characteristics of ITO materials, in order to expand therange of applications of the material.Using control variable method, changing the experimental conditions and otherfactors in the preparation process, we got the optimal conditions to prepare optimizedITO/PI composite films via comparing the results of test. With these optimalconditions, we prepared a series of composite films.By means of SEM, UV-vis and XRD techniques, we found that the ITO micronized dispersed in polyimide very well, so composite film showed a relativelygood performance of optical transmission. The obtained results of TGA, DMA, andtensile test indicate that after the introduction of ITO nanoparticles, the thermalproperties and mechanical properties of the composite film are improved. With thesurface resistivity test on the composite film prepared we found that when the massfraction of the composite film of ITO fine powder exceeds18%, the resistivity of thelower surface of the film decreased by about10orders of magnitude, to about10~6Ω/square, which has reached antistatic material requirements.