Study of field-induced chain conformation transformation in poly(L-lactic acid) based piezoelectric film by infrared spectroscopy
Published in Journal of Applied Physics, 2016
Recommended citation: Xinyu Du, Chunlin Zhao, Jinxi Zhang, and Kailiang Ren, "Study of field-induced chain conformation transformation in poly(L-lactic acid) based piezoelectric film by infrared spectroscopy", J. Appl. Phys. 120,164101 (2016) https://doi.org/10.1063/1.4965716
Abstract
In this investigation, the chain conformation transformation of the piezoelectric polymer of a poly(L-Lactic Acid) (PLLA) film was analyzed under an electric field for the first time using infrared spectroscopy. It is revealed that the piezoelectric shear mode coefficient d14 (∼10 pC/N) of a stretched α form PLLA film mainly comes from the rotation of C=O dipoles inside the polymer main chain. The reorientation of the dipoles causes the deformation of the crystal structure, which corresponds to a shear mode strain macroscopically in the PLLA film along a 45° direction to the polymer length. The back-bone of the molecular chain keeps its own conformation of a 103 helix under an external field up to 100 MV/m