From Flammability to Free Volume: An Examination of Functional Additives in Polymer Composites
Abstract
The properties of polymer systems are highly sensitive to the additives used in their formulation. A wide variety of additives from mechanical property modifers, environmental stabilizers, and processing aids can be used to change the properties of the polymer for different geometries, applications and environmental conditions. New characterization techniques are needed to understand the impact of additives on the structure, properties, and environmental fate of polymers. Here, work has been performed to quantify the risk to human and aquatic health arising from the environmental degradation and subsequent release of additives and small molecules from different commodity polymer systems. Current legislation and industry trends have identfied brominated flame retardants (BFRs) as a class of materials which has high potential for replacement or substitution. Lignin was examined as a potential sustainable replacement for BFRs in certain applications. Lignin was incorporated into epoxy as a potential substitute in printed circuit board applications. The flame retardant functionality of the lignin was enhanced through the phosphorylation of the lignin and was characterized through flammability testing. The structure - properties relationships of bauxite residue were studied and the phosphate uptake of the residue was optimized through heat treatment. Fundamental work was performed to study nanostructural differences in swollen hairy nanoparticle filled hydrogels through small angle x-ray scattering and positron annihilation lifetime spectroscopy. Better characterization of the structure and properties of functional additive-containing systems can help understand the risks associated with novel polymer systems.
Degree
Ph.D.
Advisors
Youngblood, Purdue University.
Subject Area
Polymer chemistry|Sustainability|Materials science
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