Precise detection of local relaxation of amorphous polymers at low temperatures via O2 diffusion probed by a dual-luminescent imide compound

Abstract

Local relaxation (LR) of six types of amorphous polymers was precisely monitored at low temperatures (<160 K) using the intensity ratio of phosphorescence (PH) to fluorescence of a dual-luminescent imide compound as a probe for oxygen (O₂) diffusion. The PH of the imide compound dispersed in the polymer matrices was quenched by O₂, and the temperature-dependent variation of the PH intensity indicates that the γ-relaxation of the polymer matrix plays a crucial role in O₂ diffusion. This method offers a novel analytical tool for detecting LR phenomena in amorphous polymers at low temperatures.