Thermal degradation kinetics of transparent fluorinated poly(imide siloxane) copolymers

Abstract

Fluorinated polyimide films are widely used in the field of flexible display because of their excellent optical transmittance. Based on previous studies, the adhesion to other substrates of fluorinated polyimide films have been improved by incorporating GAPD into the macromolecular chains, but their heat resistance is not yet very clear. In this study, thermal behaviors of fluorinated polyimide films (PIs) with and without GAPD were studied in N2 ambient and atmosphere by TG-DTG analysis under non-isothermal conditions. Activation energies (Eas) of PIs were calculated by Flynn-Wall-Ozawa method, Kissinger-Akahira-Sunose method and Kissinger method. In addition, mechanisms of thermal decomposition reaction were determined by Coats-Redfern method. By comparison, the Eas of PIs in the same atmosphere were similar and the thermal reaction mechanisms were essentially the same, indicating that adhesion of fluorinated polyimide can be improved by adding appropriate amount of GAPD, while the excellent optical permeability and heat resistance of fluorinated polyimide can be maintained, further expanding its application in flexible display and other fields.