RING DEHYDRATION MECHANISMS AND KINETICS OF POLYAMIC ACID MODELS IN SOLUTION AND IN THE SOLID-STATE

We have synthesized and studied the ring dehydration mechanisms and ki netics of polyamic acid models in solution and in the solid state usin g C-13-NMR (solid and liquid), HPLC, FTIR, and x-ray diffraction. Resu lts obtained in solution show the role of temperature, catalysts, and the basicity of the amine in ring dehydration mechanisms and kinetics, as well as conformation and intramolecular bonds in the amic acid bon d in the solid state. (C) 1993 John Wiley & Sons, Inc.