Alexander Salmon

(Advisors: Prof. Scott Danielsen, Prof. Jason Azoulay, and Prof. Natalie Stingelin)

Will propose a doctoral thesis entitled,

Post-Polymerization Modification of Aromatic Polymers and their Blends

On

Friday, November 6, 2026 from 12:30 pm – 2 pm ET

Molecular Science and Engineering Room 1224

Committee

Prof. Scott Danielsen, School of Materials Science and Engineering (Advisor)

Prof. Jason D. Azoulay, School of Chemistry and Biochemistry, and Materials Science and Engineering (Advisor)

Prof. Natalie Stingelin, School of Materials Science and Engineering (Advisor)

Prof. Will Gutekunst, School of Chemistry and Biochemistry

Prof. Rampi Ramprasad, School of Materials Science and Engineering

Abstract

Aromatic polymers, such as poly(ethylene terephthalate) (PET), polystyrene (PS), and polysulfone (PSU), are widely used because of the robust properties imparted by the aromatic units within their backbones. Unfortunately, these same properties prevent degradation and render their recycling and upcycling exceptionally difficult. Chemical post-polymerization modification (PPM) can produce materials with specialized properties, enabling their use in high-value industries. Unfortunately, traditional methods have limited substrate scope and can degrade the polymer chains. Gold-catalyzed direct C–H bond activation has recently been demonstrated as a method of modifying the aromatic rings of polymers, enabling the attachment of a wide range of pendants. The goal of this thesis is to determine how PPM changes the bulk and interfacial properties during and after synthesis. Aim 1 tests the bulk, determining the effect of pendant size, degree of functionalization, polarity, and intermolecular interactions on the thermomechanical and morphological properties. Aim 2 examines interfaces, testing the hypothesis that alkyl pendant length governs domain size, and mechanical properties in PET/polyethylene (PE) blends by controlling migration and anchoring. Aim 3 concludes with synthesis, determining whether catalyst structure and milling conditions allow PET chains to be functionalized with minimal degradation. Combined, these three aims will elucidate how PPM can be used to change the properties of aromatic polymers and their blends.