Synchrotron X-ray tomography for 3D chemical distribution measurement of a flame retardant and synergist in a fiberglass-reinforced polymer blend.
A fiberglass-reinforced polymer blend with a new-generation flame retardant is studied with multienergy 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. Also, the glass fibers are only slightly larger than the 3.26 microm voxels and, due to their high concentration, exist as partially aligned bundles in the polymer matrix. To investigate the chemical composition surrounding the glass fibers, new procedures were developed to find and mark the fiberglass and then assess the flame retardant distribution near the fiber bundles. On the basis of the multienergy imaging across Br and Sb K-edges, the absorbance values were converted to volume percent concentrations. Besides the basic question of the successful and stable blending of the flame retardant and synergist within the polymer matrix, we are also interested in precipitation reactions that might concentrate or diminish concentrations in the close vicinity of the fiberglass reinforcement. Thus, a procedure was developed to analyze radial concentrations about selected, well-isolated fiberglass bundles. Overall, the results show a nicely homogeneous system to the level of the tomography resolution, 3.26 microm, with some enhanced concentration near, approximately 20 microm, the fiber bundles.
Barnett
Heath A
HA
Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, USA.
Ham
Kyungmin
K
Scorsone
Jason T
JT
Butler
Leslie G
LG