The dependence of the water sorption behavior of polyimide thin films upon different diamine fragments was gravimetrically investigated. It was found that the diffusion coefficient and water uptake were strongly dependent upon the internal linkage in the diamine fragment, and varied in the range of 1.6×10-10 13.5×10-10 cm2/s and 1.52 ∼ 5.63 wt.%, respectively. The water sorption behavior of the polyimide films decreased with increasing bulkiness of the internal linkages in the diamine fragments: BPDA-PDA<BPDA-Bz<BPDA-ODA<BPDA-DDS<BPDA-FDA. Specifically, BPDA-DDS and BPDA-FDA polyimide films with bulky internal linkages in the diamine fragments showed poor chain orientation and low intermolecular packing order, leading to relatively high water sorption (i.e. fast diffusion and high water uptake).
Bibliographical noteFunding Information:
This work was supported by Center for Electronic Packaging Materials of Korea Science and Engineering Foundation.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Mechanics of Materials
- Polymers and Plastics
- Materials Chemistry