Synthesis of Polyimides Containing Triphenylamine-Substituted Triazole Moieties for Polymer Memory Applications

A series of thermally stable aromatic polyimides containing triphenylamine substituted triazole moieties (AZTA PI)s were prepared and characterized The glass transition tern peratures (T-g) of the polyimides were found to be in the range of 262-314 degrees C The polyimides obtained by chemical imidization had inherent viscosities of 0 25-0 44 dL g(-1) in N methyl 2 pyrrolidinone The number average molecular weights (Me) and weight average molecular weights (M-w) were 1 9-32 x 10(4) and 3 2-5 6 x 10(4) respectively and the polydispersity indices (PDI = M-w/M-n) were in the range of 1 70-1 78 A resistive switching device was constructed from the 4 4 ' hexafluoroiso propylidenediphthalic dianhydride based soluble polyimide (AZTA Pla) in a sandwich structure of indium tin oxide/poly mer/Al The as fabricated device can be switched from the initial low conductivity (OFF) state to the high conductivity (ON) state at a switching threshold voltage of 2 5 V under either positive or negative electrical sweep with an ON/OFF state cur rent ratio in the order of 10(5) at -1 V The device is able to remain in the ON state even after turning off the power or under a reverse bias The nonvolatile and nonrewritable natures of the ON state indicate that the device is a write once read many times (WORM) memory (c) 2010 Wiley Periodicals Inc J Polym Sci Part A Polym Chem 48 5790-5800 2010