The Polymer Society of Korea

Abstract

Water-borne poly(amic acid) salt (W-PAAS) is an eco-efficient polymer precursor for high-performance polyimide (PI) material, utilizing water as the synthetic and processing solvent. Conventionally, W-PAAS is converted to PI through the thermal imidization at a temperature above 350 °C. However, this process should be carefully considered because the organic base exhibits catalytic activity in the cycloaddition reaction, which changes the imidization temperature. Moreover, the residual organic base deteriorates the resulting physical properties by disrupting interchain interactions in the PI matrix. In this study, we studied the chemical conversion of W-PAAS by systematically tracking the evaluation of the imide groups during the thermal process. By comparing the organic bases with different basicity, the imidizaiton mechanism and residual base behavior were elucidated, which is critical for the mechanical performance of the resulting PI materials.