| 초록 |
Polyimide/polyimide molecular composite (MC) films were prepared by embeding a stiff polyimide (PIS) in ductile matrix polyimide (PIF) by blending their respective precursor solutions, followed by casting, drying, and thermal imidization. Pyromellitic dianhydride (PMDA) and oxydianiline were used as monomers for the preparation of matrix component. The reinforcing component was prepared from PMDA and 1,5-diaminonaphathalene. The resulting MC films were transparent, tough, and creasable upto 40 wt% of PIS loading. The tensile moduli were found to increase initially while the elongations to break decrease gradually on increasing the PIS content. The tensile modulus of the composite utilizing 30 wt% of PIS was 48% higher than that of pure PIF . Viscoelastic measurements showed a single and enhanced value of Tg for MCs films indicating the miscibility of this polyimide pair. The thermogravimetric analysis showed insignificant decomposition of these polyimides below 500C in nitrogen. |
