Isothermal Equation of State of Polyether Ether Ketone (PEEK) by Optical Imaging Method in Diamond Anvil Cell

Polymers serve as important functional materials in various environments, including high-pressure conditions. However, the behavior of polymers under high pressure is currently less understood. In this study, the isothermal equation of state of polyether ether ketone (PEEK), an important polymer, was measured using the diamond anvil cell technique at up to 8 GPa. The isotropic compression behavior of PEEK samples was investigated by monitoring the area change in PEEK disks during the compression process using the optical imaging method. The present results shed light on the mechanical properties of PEEK under extreme conditions, which will guide the applications of PEEK at high pressures.