Structure evolution and properties in a rigid polyimide prepared from its flexible poly(amic acid) precursor

Abstract

Soluble poly(p-phenylene biphenyltetracarboxamic acid) precursor was converted to the polyimide by thermal imidization at various conditions. The structure evolution being occurred during its thermal imidization over 25-400 degrees C was investigated as a function of imidization temperature and time by X-ray scattering with synchrotron radiation sources of Pohang Accelerator Laboratory in Korea and with conventional radiation sources. In addition, properties in the polyimide films were investigated by dynamic mechanical thermal analysis, stress-strain analysis, prism coupling, and residual stress analysis.