Although polyethylene is one of the most common plastics, it is still a polymer that is actively being researched to produce materials with improved properties.  The design of better plastics requires understanding process-structure relationships.  In this work, confocal Raman microscopy was used to investigate the in-situ uniaxial deformation of a linear-low density polyethylene dog bone sample.  Confocal Raman microscopy,  a technique that is sensitive to the chemical and structural information of polyethylene, is used to measure changes in the orthorhombic crystalline, isotropic amorphous, and anisotropic disordered phases during a tensile test.  In addition, Raman spectroscopy is sensitive to the trans and gauche conformers in the polyethylene sample, which were monitored throughout the deformation.  Besides polyethylene phase information, orientation of the polyethylene chains is another important morphological feature that was measured using polarized Raman spectroscopy.  The changes in polyethylene structure and orientation during deformation were monitored from the elastic region of the stress-strain curve through the yield point and into the strain hardening region.  After the deformation, the polyethylene sample morphology was found to change significantly upon relaxation and lengthwise contraction of the polymer.  Confocal Raman microscopy was demonstrated to be an applicable technique for studying the in situ process effects on morphology.

Confocal Raman microscopy of the in-situ uniaxial deformation of a polyethylene dog bone

253rd National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.