Abstract by Dallin Smith
Chemistry and Biochemistry
Spectroscopic characterization of the effects of fabrication conditions and strain rate of high-density polyethylene
High-density polyethylene (HDPE) is a versatile material used in a wide array of everyday applications, from grocery bags to water pipes. Material failure can range from spilled groceries to contaminated municipal water. Detecting material failure before it visually manifests is difficult, and predicting it is even more challenging. Vibrational sum-frequency generation (VSFG) spectroscopy is a nonlinear spectroscopic method that can qualitatively and quantitatively detect structural changes that precede mechanical failure. Previous work with HDPE has demonstrated that the deformation process is affected by the strain rate. Additionally, VSFG spectra have been shown to change in response to strain rate variation. The deformation process also changes as a result of manipulating extrusion temperatures and speeds. VSFG should provide the ability to predict how HDPE produced under given conditions will deform under static and dynamic loads.