Preparation And Characterization Of Triarylamine-containing Polyimide

Electrochromic materials have the properties of a stable and reversible change ofthe optical properties under visible light range as effected either by an external voltageor by a sufficient potential, displaying reversible changes on both color andtransparency. In recent years, the research and applications of electrochromic materialshave caught great attention and become one of the hot topics,Because of the diversity of molecular design, wide color range and easy processingqualities, electrochromic polymers have raised to be one of the key areas ofElectrochromic materials. The center nitrogen atom in triarylamines can be easilyoxidized with color change, thus, triarylamine derivatives are excellent electrochromicmaterials, and are widely used in triarylamine-based polymer electrochromic materialsattributed to this stable and reversible phenomenon.Electrochromic device is a typical optical film optoelectronic thin film devices andelectronics film combining to achieve a reversible color change in the external voltagedriven. Electrochromic polymers is favored as the active layer of the device due to thewide color range, high contrast and color coloration efficiency, fast response time,good color rendering properties and optical memory.In this paper, two kinds of Triarylamine monomers and Pyromellitic dianhydrideare polymerized to get two kinds of PAA-IM with triarylamine monomers. Thestructures of these polymers were determined by FT-IR spectrometer. The thermalproperties of these polymers were investigated with thermal gravimetric analysis. Theelectrochromic properties of these polymers were studied by two kinds of electrolytesolution which are acetonitrile solution containing tetrabutylammonium perchlorate(TBPA) or4-Toluene sulfonic acid (MBSA). The electrochromic properties of thesepolymers were investigated by ultraviolet-visible spectra and cyclic voltammetry together. The electrochemical properties of these devices were examined by cyclicvoltammetry.The results showed that: two kinds of PAA-IM have distinct color changes frompale yellow to blue-green or green in the electrochromic process. The electrochemicalperformance of films and devices are different depending on different electrolytes.PAA-IM has good cycle reversibility, high efficiency and low coloration switching time.PAA-IM-1displays better electrochromic stability, response time and efficiency ofdiscoloration by using MBSA as the electrolyte.