Date of Award
9-13-2025
Document Type
Open Access Dissertation
Department
Chemistry and Biochemistry
First Advisor
Ting Ge
Abstract
Understanding the mechanical behavior of polymeric materials is critical to advancing modern technologies, from flexible electronics to sustainable adhesives. This dissertation investigates the micromechanics of polymer thin films, dual-network elastomers, and bio-based lignin materials, with an emphasis on deformation mechanisms, network topology, and mechanical properties. The work combines principles of polymer physics with materials science to uncover structure–property relationships that inform polymer design. This dissertation primarily uses coarse-grained and atomistic molecular dynamics simulations to investigate molecular-scale behavior beyond experimental reach. Through these methods, critical insights are gained into how entanglement, topology, and chain architecture govern bulk material performance. The first study investigates ductile necking in sub-100nm polymer films, where MD simulations show that entanglement networks and plane stress conditions enable stable neck formation. The second examines cross-linked linear-ring polymer blends, revealing how ring overlap reduces entanglements and tunes modulus, extensibility, and strength, which guides topology-based elastomer design. The third focuses on lignin mechanics, showing that while lignin is rigid under compression, it fails brittlely under tension via cavitation and chain pullout, with molecular weight influencing strain hardening behavior. Together, these studies bridge molecular architecture with macroscopic mechanics, providing computational strategies and mechanistic insights for the design of high-performance and sustainable polymer materials.
Rights
© 2025, Siteng Zhang
Recommended Citation
Zhang, S.(2025). Molecular Architecture and Mechanical Response in Polymeric Materials: Thin Films, Linear-Ring Elastomers, and Lignin. (Doctoral dissertation). Retrieved from https://scholarcommons.sc.edu/etd/8631