Biphenyltetracarboxylic dianhydride-(perfluoromethyl) benzidine (BPDA-PFMB) polyimide/m-cresol solutions showed thermoreversible gelation associated with thermally induced phase separation and subsequent liquid crystal formation. In this study, phase equilibria and structure evolution in a BPDA-PFMB/m-cresol solution were investigated by differential scanning calorimetry, polarized optical microscopy, and depolarized light scattering. A temperature-composition phase diagram of BPDA-PFMB/m-cresol was established by a cloud point method. Kinetic aspects of the phase transition were studied in the framework of a nucleation and growth theory. The average domain size, which characterized the length scale of rigid-rod aggregates, was found to depend on supercooling.
All Science Journal Classification (ASJC) codes
- Organic Chemistry
- Polymers and Plastics
- Inorganic Chemistry
- Materials Chemistry