Organic Chemistry Commons^™

N-Aryl Phenoxazines As Polymer Supported Photocatalysts, Mary Kathryn Hall

Master's Theses

In photosynthesis, the energy of sunlight is perfectly harnessed to facilitate the production of small molecules that are essential for plant life on earth. Inspired by this model of energy efficiency and simplicity, this work seeks to mimic that ability to use the energy in visible light to perform new and more efficient chemistries. Just like in photosynthesis, photocatalysts can act as chromophores absorbing light to excite electrons opening new pathways for previously untapped reactivity. Recent research has provided a wide range of small molecule reactions that are made possible or easier by the use of a photocatalyst. However, these …

The Potential Importance Of Microenvironment On Polymer Bound Chemical Reagents, Nathan Joseph Halsteter

Theses and Dissertations

In this thesis will provide a brief history of polymer bound reagents, their uses, and advancements. The importance of polymer microenvironments will be explored using a model kinetic resolution reaction utilizing polymer bound reagents to observe how changes in a polymer’s microenvironment effects the yield and selectivity of a reaction. It was found that there are copious factors that affect polymer bound reagents, and no direct conclusion could be drawn from the study.

Exploring Soybean Oil-Based Polyol And Effect Of Non-Halogenated Flame Retardants In Rigid Polyurethane Foam, Sahithi Kondaveeti

Electronic Theses & Dissertations

To address the increasing demand for sustainable biomaterials due to the depletion of fossil fuel resources and growing environmental concerns, a new type of biodegradable and environmentally friendly rigid polyurethane foam (RPUF) has been synthesized. These foams are derived from chemically modified soybean oil-based polyol obtained from soybean oil by epoxidation followed by a ring-opening reaction. Polyurethane foam is generally used in construction, furniture, and automobile industries but is highly flammable and releases toxic gases and smoke during combustion. In this study, a highly efficient synergistic effect halogen-free flame-retardant (FR) melamine salt, 2-carboxyethyl(phenyl)phosphinic acid melamine salt (CMA) was synthesized from …

Gold(I)-Hydroarylation In Polymer Modification – Alkynes And Alkenes With Unexpected Reactivity, Samuel B. Hunt

Dissertations

Polymer modification is crucial for developing new properties and materials from recalcitrant waste polymers. Synthetically, polymers possess a chemical inertness that renders their functionalization challenging. Specifically, the omnipresence of C–H bonds in all commercial polymers endows their chemical resistance. Thus, developments in C–H activation chemistry are crucial to polymer diversification processes and allow for fundamental insight into the role of material processing conditions on novel chemical reactions. Au(I)-chemistry has recently come to the fore owing to a unique chemical reactivity nonexistent with other transition metals. The alkynophilicity of Au(I), in tandem with their insensitivity to common polymer processing conditions (air, …

Paek- And Pes-Like Perarylated Phosphonium Ionenes: Synthesis, Thermal Properties, And Conductivity, Samantha Sims

Murray State Theses and Dissertations

Ionic liquids (ILs) are useful for many applications due to the tunability of their characteristic properties making these salts ideal for many applications. To further increase possible areas of application for these materials, some ILs can be incorporated into polymer structures to form poly ionic liquids (PILs) or ionenes. The specific ions used within the material will determine the thermal, mechanical, and chemical stability properties exhibited by the polymer. Adjustments can be made to the ion structures during the synthetic process to influence these observed properties.

Fuel cells, batteries, solar cells, and capacitors, all require materials that can withstand high …

Synthesis Of Functional Chalcone Library For Use In Aza- Dipyrromethene Dye Systems, Kendal Crawley

Murray State Theses and Dissertations

Over the past decade, Aza-Bodipy dyes (ADPs), a derivative of the extensively studied BF₂-dipyrromethene (BODIPY), have become a growing field of research due to their unique photophysical properties, high yielding synthesis, and relative stability. They possess a unique spectral window of 600 to 750 nm which is the red to near-IR region, evidenced by the blue color of many of these dyes. Increasing interest in these dyes is due to this near-IR window which is important for many applications.^1-4 ADP chromophores also have a common core motif to that of phthalocyanines which allow for coordination at their …

Poly(Β-Gal-Thr): A New Scalable Synthetic Mucin, Manuel A. Lema

Dissertations and Theses

A method for the preparation of glycosylated polypeptides via the nucleophilic ring-opening polymerization of a glycosylated N-carboxyanhydride (NCA) monomer is reported. The synthesis of 2,3,4,6-tetraacetyl-β-galactose-threonine N-carboxyanhydride (β-AcO-Gal-Thr-NCA) monomer in 5 steps with an 8 % overall yield is described, and the single-crystal X-ray structure is provided. The effect of a series of Ni⁰-based organometallic initiators, nucleophilic amine initiators, co-catalysts, and solvents on the polymerization were explored. The kinetics of the three most promising conditions were studied in greater detail. The conditions that provided the highest yield, low polydispersity (Ð), and …

Thermal, Mechanical, And Rehealing Properties Of Cross-Linked Ionene Networks, Katelyn Lindenmeyer

Honors College Theses

Polymers which contain ionic liquid groups have numerous applications in a wide variety of fields. Past research from our group has shown that IL-containing polymers which exist in covalently crosslinked networks can exhibit good ionic conductivities despite the hindrance in polymer chain mobility and relaxation. In part one of this thesis, efforts to create ionic networks which have the capability of being rehealed after exposure to an external stimulus are discussed. Thermoreversible maleimide-furan chemistry was incorporated into an imidazolium-containing ionene network. Maleimide-terminated, imidazolium-containing monomers were coupled with furan-functionalized monomers, prepared from commercially available multifunctional acrylates. Thermal, mechanical and rheological characterization …

Advancements In Bio-Based Novel (Co)Monomers For Polymeric Materials, Khristal Anne Monroe

College of Graduate Studies: Theses & Dissertations

Most current research in the area of sustainable and environmentally friendly materials relate to the use of renewable sources for the fabrication of bio-based polymers and composites. Using plant-based derivatives is a common strategy. Pine sap can be distilled into turpentines (light fraction) and pine rosin (heavy fraction). Pine rosin is obtained as a brittle solid and its major component is abietic acid. This project aims at investigating a synthetic approach for the synthesis of a pine rosin-based polymer that can be potentially used for manufacturing a collection device for pine sap. The synthetic strategy consisted in the preparation of …

Filtration Apparatus Design For Oil-Water Separation Using Membranes And Sponges, Alec Jerger

Williams Honors College, Honors Research Projects

It can be difficult to separate water and oil emulsions through traditional filtration. Therefore, investigations of filtering using thermo-responsive (TR) polymers, in this case poly(vinyl methyl ether) (PVME), was conducted. It’s hypothesized that below its lower critical solution temperature (LCST), PVME has an affinity for water while oil substances do not. Above the LCST the opposite will be true. To verify this hypothesis, iterations of filtration designs were created to provide optimum control over the parameters to measure flow. The final optimized experimental apparatus was a Chromaflex glass column which was air tight and controlled all parameters besides fluid flow. …

Towards Completely Automated Glycan Synthesis, Matteo Panza

Dissertations

Carbohydrates are ubiquitous both in nature as biologically active compounds and in medicine as pharmaceuticals. Although there has been continued interest in the synthesis of carbohydrates, chemical methods require specialized knowledge and hence remain cumbersome. The need for development of rapid, efficient and operationally simple procedures has come to the fore. This dissertation focuses on the development of a fully automated platform that will enable both experts and non-specialists to perform the synthesis of glycans. Existing automated methods for the synthesis of oligosaccharides are highly sophisticated, operationally complex, and require significant user know-how. By contrast, high performance liquid chromatography (HPLC) …

Multidimensional Mass Spectrometry Of Chemonic™ Ccg-6 Nonionic Surfactant With Separation By Polarity And Shape, Charles Johnson

Williams Honors College, Honors Research Projects

Chemonic™ CCG-6 surfactant is a water-soluble poly(ethylene glycol) (PEG) conjugated alkyl glyceride emollient. This surfactant exists as a complex mixture of a glycerol cores conjugated with poly(ethylene glycol) branches (PEGylation) that were partially esterified with caprylic (C8) and capric (C10) acids. These may be esterified on one, two, or all three arms of the glyceride. The architecture of the structures in this mixture was studied using multidimensional mass spectrometry (MS). Mass spectrometry was interfaced with ultra-performance liquid chromatography (UPLC) and ion mobility (IM) separation. The mixture was separated by reversed-phase LC, oligomers of the star-branched polymer were separated according to …

Investigations Into Ring-Opening Polymerization Of Functionalized Ε-Caprolactones, Danielle N. Coderre, Matthew K. Kiesewetter

Senior Honors Projects

Polymers are defined as large molecules constructed from small, repeating units (monomers) which make up everyday items, such as: plastic bags and bottles, waterproof coatings, pipes, etc. H-bonding urea (U) or thiourea (TU) catalysts paired with base cocatalysts used for organocatalytic ring-opening polymerization (ROP) of cyclic esters have been shown to exhibit fast rates of polymerization and result in polymers with controlled molecular weights (Mn) and low polydispersity indexes (PDI). Additionally, organocatalytic ring-opening polymerization (ROP) techniques have been shown to be tolerant of the incorporation of functional groups into the monomer feed, which is vital for the catalytic synthesis of …

Synthesis And Properties Of Bisimidazolium And Poly(Ethylene Glycol)-Containing Michael Addition Polyester Networks, Joshua Allan Dippie

Murray State Theses and Dissertations

Poly(ionic liquid)s (PILs) have been examined in recent years for applications in various technologies, including solid-state lithium ion batteries and gas separation membranes. In this work, a series of bisimidazolium-containing, Michael addition donors were synthesized and used to produce a series of covalently crosslinked PIL polyester networks containing bis(trifluoromethylsulfonyl)imide as the counteranion. Within the series, the length of alkyl spacer between the two imidazolium cations and the diacrylate to acetoacetate monomer ratio were varied in an attempt to correlate structural variations with the thermal, mechanical, and conductive properties of the PILs. Keeping the diacrylate to acetoacetate ratio constant, increasing the …

Latent Cysteine Residues From Polymers Prepared Via Free And Controlled Radical Polymerizations, Douglas Vincent Amato

Master's Theses

One less commonly used “click” reaction is thiazolidine chemistry. Thiazolidine chemistry is a commonly used reaction used in biological systems because the reaction requires the presence of both cysteine (a common amino acid) and an aldehyde or ketone. If cysteine residues could be incorporated into a polymer then a variety of applications could be developed. Polymers containing free thiols (aka thiomers) have developed in the last decade to become great mucoadhesives. If there was a facile route to control the amount of free thiols along the polymer then more fine-tuned and potentially stronger adhesives could be made. For these reasons …

Re-Healable Coating Based Upon Thermally Responsive Linkages, Dahlia Ningrum Amato

Master's Theses

The goal of this thesis was to design thermally responsive polyol resins that would be compatible with isocyanates. Two approaches were made to reach this goal, the first involved functionalizing soybean oil and the second involved post-polymerization modification of a methacrylate based resin.

A soybean based coating with thermally responsive Diels-Alder linkages has been prepared following an automotive two-component formulation. The resulting coatings displayed the capability to be healed following physical deformation by a thermal stimulus, and such a material has significant potential for end users. Various curing agents were employed, and resulted in variation of scratch resistance and re-healablity. …