Date of Award
12-2025
Degree Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
School
Polymer Science and Engineering
Committee Chair
Dr. Jeffrey Wiggins
Committee Chair School
Polymer Science and Engineering
Committee Member 2
Dr. Andrea Browning
Committee Member 3
Dr. Derek Patton
Committee Member 3 School
Polymer Science and Engineering
Committee Member 4
Dr. Sergei Nazarenko
Committee Member 4 School
Polymer Science and Engineering
Committee Member 5
Dr. James Rawlins
Committee Member 5 School
Polymer Science and Engineering
Abstract
This dissertation aims to expand the fundamental understanding of diamine-based benzoxazine chemistry by examining how synthesis influences the network properties of 4,4’-ddm and phenol-based (P-ddm) benzoxazine, compared to the constitutionally isomeric bisphenol-F and aniline-based (BF-a) benzoxazine. While bisphenol-based benzoxazines such as BF-a have been studied more extensively, diamine-based benzoxazines are still relatively unexplored due to the competition with the formation of 1,3,5-hexahydrotriazine intermediates and the inconsistent thermal and mechanical properties reported in the literature. These inconsistencies stem from factors including synthetic methods, curing conditions, and degradation during polymerization that have been overlooked.
To address these issues, this dissertation is organized into three main experimental sections. Firstly, new synthetic methods for P-ddm were developed and evaluated, and the resultant networks were characterized to assess the influence of triazine formation and monomer purity on network development and properties. Secondly, networks of BF-a prepared through melt- and solution-based methods were compared to a commercial equivalent, with particular focus on the overlap of curing and degradation at high temperatures. Finally, the impact of cure environment was examined by comparing Poly(P-ddm) and Poly(BF-a) networks polymerized in oxidative and inert conditions. Throughout, molecular dynamics (MD) simulations were used to explore atomistic differences in bond dissociation, triazine incorporation, and structure-property relationships.
Collectively, these results demonstrate that synthetic pathways, cure environment, and molecular connectivity govern polymerization behavior and network performance, providing a framework for reproducible, high-performance polybenzoxazines.
Copyright
Benjamin L. G. Morasch, 2025
Recommended Citation
Morasch, Benjamin L. G., "Elucidating Differences in Constitutionally Isomeric Diamine- and Bisphenol-based Polybenzoxazine Networks" (2025). Dissertations. 2402.
https://aquila.usm.edu/dissertations/2402