Synthesis and memory characteristics of novel soluble polyimides based on asymmetrical diamines containing carbazole

Two novel asymmetrical carbazole-based diamines 9-(2-(1,1'-binaphthyl-4-yl) benzyl)-9H-carbazole-3,6-diamine (BNBCD) and 9-((4'-(9H-carbazol-9-yl)biphenyl-2-yl)methyl-9H-carbazole-3,6-diamine (CBMCD) were synthesized. A series of novel soluble aromatic polyimides were prepared from these diamines by poly-condensation with Pyromelitic dianhydride (PMDA) and 2,2',3,3'-biphenyl tetracarboxylic dianhydride (BPDA) via a two-step procedure. The resulting polymers were fully characterized, they exhibited excellent organosolubility and high thermal stability with the temperature of 5% weight loss under nitrogen atmosphere over 400 degrees C. Resistive switching devices with the configuration of Al/polymer/ITO were constructed from these polyimides by using conventional solution coating process. The memory devices based on PI-a, PI-b and PI-c exhibited a flash type memory capability, whereas the PI-d presented a write once read many times (WORM) memory capability. (C) 2016 Elsevier Ltd. All rights reserved.