Three-Dimensional Molecular Orientation Imaging of a Semicrystalline Polymer Film under Shear Deformation

Published

March 31, 2022

Author(s)

Young Jong Lee, Shuyu Xu, Chad R. Snyder, Jeremy Rowlette

Abstract

The 3D molecular orientations of polymer chains are imaged and compared for a quiescent spherulite region and a shear deformed region of a semicrystalline poly(e-caprolactone) (PCL) film. The images of 3D orientation are acquired by a newly developed hyperspectral imaging method based on the orthogonal-pair polarization IR (OPPIR) analysis. Polymer chains in spherulites are azimuthally aligned perpendicular to the crystal growth direction and axially tilted from the film normal direction. By contrast, polymer chains in a sheared region are azimuthally aligned along the shear direction but axially tilted from the shear direction. The unexpected out-of-plane tilted orientation indicates that orientational relaxation follows shear deformation and occurs predominantly in the out-of-plane direction. Furthermore, the OPPIR analysis of spectrally deconvoluted peaks shows that crystalline and amorphous chains are oriented aligned at different angles, possibly due to different orientational relaxation between the two chain configurations.

Citation

Macromolecules

Volume

55

Issue

7

Pub Type

Journals

Download Paper

https://doi.org/10.1021/acs.macromol.1c02036

Local Download

Keywords

3D orientation, polarization IR, IR microscopy, polymer, deformation

Citation

Lee, Y. , Xu, S. , Snyder, C. and Rowlette, J. (2022), Three-Dimensional Molecular Orientation Imaging of a Semicrystalline Polymer Film under Shear Deformation, Macromolecules, [online], https://doi.org/10.1021/acs.macromol.1c02036, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=933403 (Accessed October 11, 2025)