| Popis: |
2,2′-Position aryl-substituted tetracarboxylic dianhydrides including 2,2′-bis(biphenyl)-4,4′,5,5′-biphenyl tetracarboxylic dianhydride and 2,2′-bis[4-(naphthalen-1-yl)phenyl)]-4,4′,5,5′-biphenyl tetracarboxylic dianhydride were synthesized. A new series of aromatic polyimides (PIs) were synthesized via a two-step procedure from 3,3′,4,4′-biphenyl tetracarboxylic dianhydride and the newly synthesized tetracarboxylic dianhydrides monomers reacting with 2,2′-bis[4′-(3″,4″,5″-trifluorophenyl)phenyl]-4,4′-biphenyl diamine. The resulting polymers exhibited excellent organosolubility and thermal properties associated with Tg at 264 °C and high initial thermal decomposition temperatures (T5%) exceeding 500 °C in argon. Moreover, the fabricated sandwich structured memory devices of Al/PI-a/ITO was determined to present a flash-type memory behaviour, while Al/PI-b/ITO and Al/PI-c/ITO exhibited write-once read-many-times memory capability with different threshold voltages. In addition, Al/polymer/ITO devices showed high stability under a constant stress or continuous read pulse voltage of − 1.0 V. Copyright © 2011 Society of Chemical Industry |
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