Optimization of the Crystalline Structure of Interlocked Polymer for Piezoelectric Elastomer

Piezoelectric materials have a wide range of applications in various fields but generally have poor mechanical toughness. To increase the applicability of these materials, it is essential to increase their mechanical properties. In this study, a tough piezoelectric polyrotaxane (PRX) elastomer was developed by mixing two different length PRXs to improve its piezoelectric properties through dipole moment alignment. The effects of mixing ratio of the PRXs on the crystalline structure were investigated by XRD and TEM. In addition, the ferroelectric and piezoelectric properties of the PRX elastomer were evaluated based on its polarization hysteresis loop and voltage generation, respectively. The PRX elastomer formed using a ratio of 3:1 (ePR10k₇₅35k₂₅) exhibited a long-range-ordered anisotropic crystalline, resulting in a large polarization (P_r) value. As a result, ePR10k₇₅35k₂₅showed significantly enhanced piezoelectric sensitivity to mechanical vibrations generated by respiration.