Transparent Polyimide Film with Improved Water and Oxygen Barrier Property by In-Situ Exfoliating Graphite

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• 作者：Mei-Hui Tsai ; I-Hsiang Tseng ; Yi-Chia Huang ; Hsin-Pei Yu and Po-Ya Chang
• 刊名：Advanced Engineering Materials
• 出版年：2016
• 出版时间：April 2016
• 年：2016
• 卷：18
• 期：4
• 页码：582-590
• 全文大小：1822K
• ISSN：1527-2648

文摘

A facile process is demonstrated to fabricate flexible and transparent polyimide (PI) thin films with improved moisture and oxygen barrier property by in situ solution-blending PI monomers with ultrasonicated graphite sheets in the solvent during imidization process. When the concentration of graphite in solvent is less than 0.3 wt%, graphite can be exfoliated to a thickness of less than 800 nm and homogeneously distributed in the precursor of PI solution. The resultant PI composite films containing exfoliated graphite (xG) show excellent transparency, enhanced mechanical strength, improved thermal stability and sufficient electrical insulation. Most importantly, the barrier property of PI/xG composite film is significantly improved by the distributed xG sheets in PI matrix. With the addition of 0.06 wt% of xG in PI matrix, the PI/xG-0.06 film show an oxygen-transmission-rate (OTR) of 152 cc/m²-day compared to 301 cc/m²-day for pure PI. The reduction degree in water-vapor-transmission-rate (WVTR) by xG is higher than that in OTR. The WVTR of PI/xG-0.06 is 28 g/m²-day, which is only 17% of the value of pure PI. Those PI/xG thin films show the potential as substrate materials for modern flexible electronic devices.