X-RAY AND ELECTRON-DIFFRACTION STUDIES OF LANGMUIR-BLODGETT-FILMS OF POLY(4,4'-OXYDIPHENYLENE)PYROMELLITIMIDE

Multilayer films of polyimide precursor - cetyl ester of poly(4,4'-oxy diphenylene)pyromellitamic acid - were deposited on a silicon support by the Langmuir-Blodgett technique. During thermal and chemical imidiz ation of the precursor, poly(4,4'-oxydiphenylene)pyromellitimide with an ordered structure was formed. On the basis of electron diffraction patterns, mutual arrangement of polyimide chains was described by an o rthorhombic cell with the following parameters: a = 6.31, b = 3.97, c = 32 Angstrom. It was shown that the bilayers of precursor can be inco rporated into a superlattice so that they alternate with the bilayers of cadmium behenate. Using SAXS, the thickness of the bilayer of the p recursor was determined to be (43 +/- 1 Angstrom).