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

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(epsilon-caprolactone)film. To acquire the images of 3D orientation, we used a newlydeveloped hyperspectral imaging method based on the orthogonal-pair polarization IR (OPPIR) analysis. Polymer chains inspherulites are azimuthally aligned perpendicular to the crystalgrowth direction and axially tilted from thefilm normal direction.By contrast, polymer chains in a sheared region are azimuthallyaligned along the shear direction but axially tilted from the sheardirection. The unexpected out-of-plane tilted orientation indicatesthat orientational relaxation followed shear deformation andoccurred predominantly in the out-of-plane direction. Further-more, incorporating peak deconvolution into the OPPIR analysis shows that the crystalline and amorphous chains are orientedaligned at different angles, possibly due to different orientational relaxation between the two chain configurations.