| Abstract
| - A new adamantane-based dietheramine, 2,2-bis[4-(4-aminophenoxy)phenyl]adamantane,was prepared in two steps from chloro displacement of p-chloronitrobenzene with the potassium phenolateof 2,2-bis(4-hydroxyphenyl)adamantane, followed by hydrazine catalytic reduction of the intermediatedinitro compound. A series of polyimides with the adamantane-2,2-diyl unit as a cardo group was preparedfrom the adamantane-based dietheramine and various aromatic dianhydrides by a conventional two-stage synthesis in which the poly(amic acid)s obtained in the first stage were heated stage-by-stage at150−270 °C to give the polyimides. The intermediate poly(amic acid)s had inherent viscosities between0.82 and 1.66 dL/g. Except for the polyimide from pyromellitic dianhydride, all of the polyimides couldbe dissolved in NMP, and several polyimides also showed good solubility in other organic solvents. Allof the polyimides were amorphous in nature as evidenced by X-ray diffractograms. The glass-transitiontemperatures (Tg) of these polyimides were recorded between 248 and 308 °C by differential scanningcalorimetry (DSC), and the softening temperatures (Ts) determined by thermomechanical analysis (TMA)stayed in the range of 254−335 °C. Decomposition temperatures for 10% weight loss all occurred above500 °C in both air and nitrogen atmospheres.
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