Lignin-derived precursors were used in the synthesis of bio-based high-performance polymers. The project consisted of synthesizing a series of poly(ester amide)s (PEAs) from lignin building blocks and natural amino acids. In particular, the amino acid moieties were incorporated into the PEAs’ architecture to explore the effect of the side-chain size on the thermal properties and the crystallinity of the resulting materials. The polymers, which were prepared by melt polycondensation, all possessed high thermal stability in nitrogen and air with onsets of thermal degradation (Td onset) exceeding 330 °C and glass transition temperatures (Tg) ranging from 136 °C – 238 °C. It is worth noting that the Tg greatly depended on the size of the pendant R-group on the amino acid. Remarkably, the thermal stability was mostly maintained even after subjecting the polymers to various pH media (pH 1, 4 and 8) for 1 week at 50 °C. Furthermore, wide-angle X-ray scattering experiments revealed semi-crystalline polymers with identical diffraction patterns and percent crystallinity ranging from 21 – 37%. To probe the impact of chirality on the thermal properties, a meso polymer of DL-alanine was prepared and compared to the chiral version. A slight drop in the Td onset and Tg of the DL-alanine-containing polymer relative to the L-alanine counterpart occurred, signifying moderate thermal stability resulting from the chiral group. Overall, these characteristics make these bio-based PEAs potential candidates for further investigation as alternatives to petrochemical-derived thermoplastics for high-performance materials.

Tailored fluoropolymers remain the leading choice for a wide variety of advanced high-performance applications, including electronic/optical and energy conversion, owing to their unique blend of complementary high-performance properties. Amorphous semi-fluorinated polymers exhibit improved solubility and melt processability when compared to traditional perfluoropolymers. A leading class of semi-fluorinated aryl ether polymers includes perfluorocyclobutyl (PFCB), perfluorocycloalkenyl (PFCA), and fluoroarylene vinylene ether (FAVE) polymers. Monomers containing aromatic trifluorovinyl ethers (TFVE) are used to synthesize PFCB polymers via radical-mediated [2+2] cyclodimerization. On the other hand, FAVE and PFCA polymers are polymerized via base-mediated nucleophilic addition/elimination of bisphenols with TFVE monomers and decafluorocyclohexene respectively. The use of different monomer cores (aromatic, aliphatic, contorted, and renewable) should help to develop general structure/property relationships for this versatile and expanding approach to semi-fluorinated aryl ether polymers. The enchainment of polycyclic aromatic hydrocarbon (PAH) cores with functional fluorocarbon groups (or segments) recently afforded a new class of semi- fluorinated polymers in the continuing quest for novel organic materials for potential applications in optoelectronic, gas-separation, and advanced composites. Chapter 2 details the incorporation of commercially available acenaphthenequinone was achieved to afford PFCB aryl ether polymers with excellent solubility, high thermal stability, and film-forming capability. Chapter 3 represents base-promoted nucleophilic addition/elimination of commercial bisphenols with TFVE-triphenylene monomers affording FAVE aryl ether polymers possessing excellent solution processability, high thermal stability and photostability. In addition, triphenylene-enchained FAVE polymers exhibit extreme thermal-oxidative photostability and emit blue light after heating in air at 250 °C for 24 h. Further, time-dependent density functional theory (TD-DFT) computations were performed to understand electronic polymer structures. In one case, post-polymerization Scholl coupling converted the central triphenylene core to afford a hexabenzocoronene containing semi-fluorinated polymer with new optoelectronic properties. Chapter 4 demonstrates synthesis and characterization of renewable semi-fluorinated polymers obtained using aliphatic diol isosorbide. This renewable diol readily polymerizes with bis-TFVE derivatives of bisphenol A and 6F to provide high molecular weight thermoplastics exhibiting excellent solubility and tough, transparent film-forming capability. Finally, Chapter 5 presents synthesis of TFVE enchained corannulene which gave blue-light emission and outstanding processability. Synthesis and characterization, including the new materials' optical, thermal, and electronic properties, is presented.