Kinetics and Mechanisms of Thermal Imidization Studies by UV-Visible andFluorescence Spectroscopic Techniques

摘要

Kinetics and mechanisms of thermal imidization in solution and solid state werestudied by UV-visible, fluorescence, FTIR, and size-exclusion chromatography, using polyamic acid synthesized from 1,5-diaminonaphthalene (DAN) and a partially fluorinated dianhydride (6FDA). Since all other reaction intermediates have negligible fluorescence, fluorescence spectroscopy was used to measure the concentration of DAN due to depolymerization from poly(amic acid), which was confirmed by size-exclusion chromatography. Deconvolution of UV-visible spectra using model compound spectra provided compositional analysis of involved species from which the rate constants were extracted. In dilute solution imidization, the