Abstract
Four different p-PDA-based polyimide thin films were prepared from their respective poly(amic acid)s through thermal imidization at 400°C: poly(p-phenylene pyromellitimide) (PMDA-PDA); poly(p-phenylene biphenyltetra carboximide) (BPDA-PDA); poly(p-phenylene 3,3′,4,4′-oxydiphthalimide) (ODPA-PDA); and poly(p-phenylene 4,4′-hexafluoroisopropylidene diphthalimide) (6FDA-PDA). Water-sorption behaviors of polyimide films were gravimetrically investigated at 25°C and 22-100% relative humidity by using the modified electromicrobalance (Thin Film Diffusion Analyzer). The diffusion coefficients of water for the polyimides varies in the range of 1.6 to 10.5 × 10-10 cm2/s, and are in the increasing order: BPDA-PDA < PMDA-PDA approx. ODPA-PDA < 6FDA-PDA. The water uptakes of polyimides vary from 1.46 to 5.80 wt %, and are in the increasing order: BPDA-PDA < ODPA-PDA < 6FDA-PDA < PMDA-PDA. The water-sorption behaviors for the p-PDA-based polyimides are closely related to the morphological structure; specifically, the diffusion coefficients in p-PDA-based polyimide thin films are closely related to the in-plane orientation and mean intermolecular distance, whereas the water uptakes are affected by the packing order.
Original language | English |
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Pages (from-to) | 1315-1323 |
Number of pages | 9 |
Journal | Journal of Applied Polymer Science |
Volume | 76 |
Issue number | 8 |
DOIs | |
Publication status | Published - 2000 |
All Science Journal Classification (ASJC) codes
- Chemistry(all)
- Surfaces, Coatings and Films
- Polymers and Plastics
- Materials Chemistry