The imidization behavior of amphiphilic salts of rigid-chain poly(amic acid)s and the structure of Langmuir-Blodgett films based on them

Langmuir-Blodgett films of amphiphilic salts of poly(amic acid)s prepared f rom 3,3',4,4-'-diphenyltetracarboxytic acid dianhydride and p-phenylenediam ine or o-tolidine, the two diamines, were obtained. The structure of these films and the relevant polyimides was shown to depend on the structure of t he polymer main chain and on the solvent. The packing of bilayers in the fi lms of the salts of poly(amic acids was analyzed with the set of diffractio n methods and by computer simulation. A comparative study of the structure of the Langmuir-Blodgett films and macroscopic films and structural changes during imidization was performed by X-ray scattering, electron diffraction , mass spectrometric, and thermogravimetric techniques. It was found that t he temperature range of cyclodehydration in the prepolymers was lowered by the action of long-chain tertiary amines and benzimidazole.