Doctor of Philosophy (PhD)
Material properties of industrial polymer blends are of great importance. X-ray tomography has been used to obtain spatial chemical information about various polymer blends. The spatial images are acquired with synchrotron X-ray tomography because of its rapidity, good spatial resolution, large ﬁeld-of-view, and elemental sensitivity. The spatial absorption data acquired from X-ray tomography experiments is converted to spatial chemical information via a linear least squares ﬁt of multi-spectral X-ray absorption data. A ﬁberglass-reinforced polymer blend with a new-generation ﬂame retardant is studied with multi-energy synchrotron X-ray tomography to assess the blend homogeneity. Relative to other composite materials, this sample is difﬁcult to image due to low x-ray contrast between the ﬁberglass reinforcement and the polymer blend. To investigate chemical composition surrounding the glass ﬁbers, new procedures were developed to ﬁnd and mark the ﬁberglass, then assess the ﬂame retardant distribution near the ﬁber. Another polymer blending experiment using three-dimensional chemical analysis techniques to look at a polymer additive problem called blooming was done. To investigate the chemical process of blooming, new procedures are developed to assess the ﬂame retardant distribution as a function of annealing time in the sample. With the spatial chemical distribution we ﬁt the concentrations to a diffusion equation to each time step in the annealing process. Finally the diffusion properties of a polymer blend composed of hexabromobenzene and o-terphenyl was studied. The diffusion properties were compared with computer simulations of the blend.
Document Availability at the Time of Submission
Release the entire work immediately for access worldwide.
Barnett, Heath Alan, "Chemical analysis of polymer blends via synchrotron X-ray tomography" (2008). LSU Doctoral Dissertations. 69.