| 초록 |
Nanoporous polyimide (PI) films were successfully prepared by calcination of polyethylene glycol (PEG) into the poly(ethylene glycol-co-imide) (PAA-PEG). Thermally labile PEG was partially introduced into polyamic acid (PAA) which synthesized by condensation polymerization of 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA) and 4,4′-Diaminodiphenyl ether (ODA). Thermal imidization and degradation processes of the spin-coated PAA-PEG films were sequentially performed through one-step heat treatment ranging from 200 to 280°C. Nanoporous pore size was increased with increasing the amount of PEG in the PAA-PEG and dielectric constants decreased. Comparing to nanoporous PI films, bulk PI film had superior tensile strength to about 70 μm thickness. PI thin films with nanopores still retain good mechanical properties on a stress-strain curve as a function of PEG content and their thermal properties were estimated. |
