Photodegradation Of A Semi-Aromatic Bio-Derived Polyimide

Recently, we have developed a thermoelectrically superior and highly transparent bio-derived polyimide using microorganism-derived 4-aminocinnamic acid. Here, the stability of the novel bio-derived polyimide under photoirradiation was systematically investigated. Infrared spectroscopy (IR), solid-state nuclear magnetic resonance (NMR), and tensile tests were employed for studying the impacts of the irradiation on both chemical and mechanical properties of the material. The structural modifications of the material were analyzed in the form of spectral expression of correlation coefficients. It was found that the bio-derived polyimide maintained its stability well up to several hundreds of hours. Elongated radiation caused deterioration at the imide ring and the tertiary carbon of the cyclobutane ring, accompanied by the growth of carbonyl species as an oxidation product. (C) 2020 Elsevier Ltd. All rights reserved.