Two polyimides having the same backbone chemical structure and different pendant side groups at the 2- and 2′-positions of the diamine, the six methylene units capped with 4-cyanobiphenyl end groups and trifluoromethyl, were synthesized (6FDA-6CBO and 6FDA-PFMB). Surface-enhanced Raman scattering and surface optical second harmonic generation measurements show that after rubbing the major change in 6FDA-PFMB surface appears in the orientation of the dianhydride, which was originally planar, but becomes tilted with respect to the surface plane. In the case of 6FDA-6CBO, rubbing also causes the originally planar 4-cyanobiphenyls to tilt away from the surface and assume an azimuthally anisotropic distribution.
|Number of pages||5|
|Journal||Macromolecular Rapid Communications|
|Publication status||Published - 1998 Dec|
ASJC Scopus subject areas
- Organic Chemistry
- Polymers and Plastics
- Materials Chemistry