[Study on testing methods of Al content of polyimide hybrid films with Al2O3]

The inorganic particles hybrid polyimide films are newly emerging advanced materials with excellent corona-resistant and have been widely used in frequency control motor. The Al2O3/PI hybrid films with different Al2O3 contents were prepared by superfine aluminum power treated by coupling agent and polyamide acid (PAA). Qualitative analysis and quantitative analysis on the inorganic content to it were conducted using Fourier Transform Infrared Spectroscope (FTIR), X-ray photoelectron spectroscopy (XPS), Inductively coupled plasma spectrometry (ICP), Gravimetric method, Thermogravimetric Analysis (TG/air atmosphere). It was found that FTIR and XPS are good qualitative analysis methods. FTIR is used to inference possible components by analyzing the structure of material. The method has a lot of advantages such as easily operational, good repeatability, high accuracy and so on. XPS is mainly used to get information of elements contained in the material, it provides information about the core level binding energies and oxidation states of complexes. It can be used to identify the species and valence states of elements, measure the relative content of elements. The relative standard deviations (RSDs) of XPS and TG are too great to perform quantitative analysis, the RSDs of XPS are all above 5.0%, and TG's RSDs are also above 2.0%. So they can be only used as semiquantitative analysis methods. On the contrary, ICP and Gravimetric method are two excellent quantitative analysis methods, their RSDs are all below 1.0%. Moreover Gravimetric method only can be used to analyze single inorganic constituent complex material, although its measured value is closest approach to theoretical value. ICP is the most accurate method and it can be used to analyze multi inorganic components in complex material, this method proved to be easily operational, rapid, highly sensitive, and accurate, and can be adopted as the method of determining many elements simultaneously. So a method was got to analysis of inorganic constituent in complex material from the conclusion upward. Firstly, components in complex material are defined by using FTIR and XPS as qualitative analysis methods and then using the result of XPS as a reference, exactly quantitative analysis of inorganic constituent in complex material was performed by using Gravimetric method and ICP.