Abstract by Dallin Smith
Chemistry and Biochemistry
Spectroscopic Effect of Polymer Strain Rate
High-density polyethylene (HDPE) is used in a wide variety of everyday materials, from artificial joints to shopping bags. Having a better understanding of its response to mechanical stress will lead to more efficient and durable materials. Vibrational sum-frequency generation (VSFG) has been used to nondestructively determine how HDPE responds to mechanical deformation. Previous results show a correlation between VSFG response and strain length at constant strain rate. The effects of varying strain rate with constant strain length are being investigated currently. A qualitative difference has been observed correlating to orientation between the strain direction and incident beam. Images from a Scanning Electron Microscope have revealed structural variations between samples pulled at various rates. Discovering how strain rate affects HDPE’s response to VSFG will contribute to a deeper understanding of the response of HDPE or other polymers when subjected to mechanical stress.