Physical Sciences and Mathematics Commons^™

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 …

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 …

Behavioral Modulation Of Supramolecular Assemblies Via Covalent And Non-Covalent Interfacial Transformations, Ann Fernandez

Doctoral Dissertations

There are several molecular level mechanisms at the origin of biological functions that serve as inspiration for the development of the “next generation” of materials that display adaptive and interactive properties. However, it will take time for synthetic materials to approach the level of complexity, robustness, and adaptability of biological systems. Although there are switchable platforms that respond via sensitized molecular components, there are currently no examples of materials that truly possess the type of autonomous behavior seen in biological systems. Even though these concepts are common in living organisms, their translation into a synthetic platform remains challenging to this …

Synthesis, Self-Assembly, And Material Applications Of Unimolecular Polyviologens, Abigail Delawder

Arts & Sciences Electronic Theses and Dissertations

Intellectual Gaps: Synthesis of high molecular weight, unimolecular, and sequence-defined polyviologens; spatiotemporal control over mechanical properties of materials using visible and near-IR light; on-demand, post hoc manipulation of materials

Intellectual Merit: Robust method for synthesizing higher-order polyviologens of distinct molecular weight; control the change in the mechanical properties of polymer-based, crosslinked materials using a wide range of wavelengths of light; degradation of viologen-crosslinked hydrogels

To understand fundamentally how viologens behave within a polymer chain, we needed a better and more efficient way of synthesizing these long chains of polyviologens. As simple as this process looks on paper, the synthesis is …

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

Electronic Theses and 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) …

Active Polymeric Materials For 3d Shaping And Sensing, Adebola Oyefusi

Theses and Dissertations

Part I: Reprogrammable Chemical 3D Shaping for Origami, Kirigami, and Reconfigurable Molding

Origami- and kirigami-based design principles have recently received strong interest from the scientific and engineering communities because they offer fresh approaches to engineering of structural hierarchy and adaptive functions in materials, which could lead to many promising applications. Herein, we present a reprogrammable 3D chemical shaping strategy for creating a wide variety of stable complex origami and kirigami structures autonomously. This strategy relies on a reverse patterning method that encodes prescribed 3D geometric information as a spatial pattern of the unlocked phase (dispersed phase) in the locked phase …

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 …

Formulation And Characterization Of Lipogels As A Tunable Delivery Scaffold, Celia Homyak

Doctoral Dissertations

Nanomedicines within the clinic commonly utilize lipid-based scaffolds due to their aqueous assembly and non-covalent dual-guest loading capabilities. Nevertheless, poor stability in vivo and premature guest release remains a challenge with these systems. Polymeric nanomaterials are a popular alternative due to their good stability in vivo with controllable guest release. A caveat to polymeric scaffolds though, is the excess synthetic effort involved for non-covalent dual-drug encapsulation. Benefit lies in harnessing advantages of lipid and polymeric materials via lipid-polymer hybrid scaffold. Such materials have promise due to their dual-encapsulation and dual-stimuli-sensitive characteristics. The need to better understand these materials led us …

Thermally Robust And Redox Active Catalysts: Studying Their Behavior For Ethylene And L-Lactide Polymerization, Lauren Ashley Brown

Doctoral Dissertations

The development of homogenous single-site catalysts has significantly impacted the field of organometallic chemistry. The well-defined structures of homogenous catalysts make it less cumbersome to understand and develop methods to tailor these compounds for specific catalytic processes. Currently, polymerization catalysis is a major division in organometallic chemistry due to the global demand for polymeric materials such as polyethylene (PE) and polypropylene (PP), based on their low-cost feedstock, remarkable mechanical properties, and their use in a wide range of applications. However, bioplastics have become a highly sought-after alternative to conventional petrochemical-based plastics due to their biodegradability and derivatization from renewable resources. …

Development Of High Performance Gas Separation Membranes Through Intelligent Catalyst And Monomer Design, Kevin Richard Gmernicki

Doctoral Dissertations

Polymer membranes are a valuable tool for separating components of liquid and gas mixtures. Heavily inspired by biological systems, the idea of using the intrinsic properties of polymers to perform otherwise energy-intensive tasks is attractive for applications such as water desalination, natural gas sweetening, and post-combustion carbon capture. Of particular interest to our research group, post-combustion carbon capture is a promising potential solution aimed at reducing the carbon footprint involved with production, transportation, and storage of electrical energy generation.

Every year, the United States produces close to seven billion metric tons of carbon dioxide, of which a significant portion is …

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 …

Metal-Ligand Cooperative Catalysis And Methods For Metal Removal From Organic Transformations, John-Paul J. Bow

Electronic Thesis and Dissertation Repository

Organometallic catalysis has revolutionized the synthesis of complex organic molecules. Methods for C-C, C-X and C-H bond formation and cleavage are exploited throughout the areas of fine chemicals synthesis, with major applications for pharmaceuticals. This situation raises duel challenges: 1) high-performance catalysts for environmentally and economically sustainable synthesis and 2) efficient methods of catalyst (i.e. metal) removal must be identified. This work tackles both of these areas. The highly tunable cooperative P^R₂N^R'₂ ligands have been implemented for the first time for catalytic organic transformations. I show that [Ru(Cp)(P^tBu₂N^Bn₂)(MeCN)][PF_{6 …}

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. …

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 …

Synthesis Of Self-Immolative Monomers And Their Applications In Polymeric Materials, Matthew A. Dewit

Electronic Thesis and Dissertation Repository

Self-immolative spacers are a unique class of molecules employed in a variety of applications, particularly in the biomedical field. Most commonly, they are molecules containing two reactive termini with a capping group at one terminus and a substrate of interest at the other. Upon removal of the capping group, the spacer undergoes an intramolecular reaction that results in its removal from the molecule and liberation of the substrate. These spacers have been extensively studied in monomeric form within prodrugs, as well as to form dendrimers that have been used for applications such as signal amplification, molecular logic gates and amplified …