Chemistry Commons^™

The Synthesis And Application Of Polyglyoxylamides, Quinton Ea Sirianni

Electronic Thesis and Dissertation Repository

Self-immolative polymers (SIPs) are a subset of degradable polymers that can be triggered to fully depolymerize with a single stimulus event. This amplifying behaviour makes them ideal for real-world applications including sensors, recyclable plastics, and drug delivery vehicles. Polyglyoxylates (PGs) are a class of SIPs that can be synthesized in a one-pot reaction and designed to respond to different stimuli including light, heat, reduction, and oxidation. However, with the exception of poly(ethyl glyoxylate) (PEtG), the various glyoxylate monomers must be prepared and purified before polymerization, which can be difficult. Furthermore, PGs typically possess properties such as water-insolubility and low glass …

Self-Immolative Polymers As A Degradable And Triggerable Class Of Surfactants, Siamak Keshtpour

Electronic Thesis and Dissertation Repository

Self-immolative polymers (SIPs) are degradable polymers that undergo end-to-end depolymerization upon triggering. They have potential for the development of degradable surfactants addressing human and environmental toxicity concerns associated with non-degradable surfactants, but they have not yet been investigated as surfactants. Herein, polyglyoxylamide SIPs with different pendent groups and end-caps were synthesized, envisioning they could serve as depolymerizable analogues of poly(vinyl alcohol) and its derivatives. Polyglyoxylamides with pendent hydroxyls stabilized both PEA and PLA particle suspensions. They showed the potential to undergo triggered degradation, resulting in destabilization of the suspensions. However, untriggered suspensions exhibited poor long-term stability, so further structural tuning …

Development Of A Route To Functional Polymers Via Click Chemistry, Kyle Classen

Electronic Thesis and Dissertation Repository

Functional polymers are desirable due to their use in applications such as drug delivery and bioimaging. This work describes the development of a functional polymer template, expanding upon current routes to creating functional polymer libraries. The methodology utilizes a masking-unmasking strategy to protect and then reveal a strained alkyne for the introduction of functional entities via post-polymerization modification.

The synthesis and characterization by high-resolution mass spectrometry as well as ¹H NMR, UV-Vis, and FT-IR spectroscopy of a masked strained alkyne monomer is presented. First, the strained alkyne, masked by a cyclopropenone moiety, was synthesized. Next, a norbornene derivative was …

Synthesis Of Stable Organic Radical Homo- And Co-Polymers And Their Applications In Solid-State Devices, Michael Anghel

Electronic Thesis and Dissertation Repository

This thesis outlines the synthesis and characterization of a stable organic radical homopolymer incorporating nitronyl nitroxide radicals, as well as the synthesis and characterization of random and block co-polymers incorporating nitronyl nitroxide and 6-oxoverdazyl radicals.

The nitronyl nitroxide homopolymer was synthesized using ring-opening metathesis polymerization (ROMP), yielding polymers with controlled molecular weights and narrow molecular weight distributions. Studies of polymer growth as a function of time and monomer:catalyst ratio revealed the ROMP to be well-behaved. Spectroscopic analysis of the polymer showed that the radicals possessed high radical content, indicating that they are tolerated by ROMP. Conductivity studies of thin-films made …

Synthesis Of Polycarbamate‒Based Nanoassemblies And Previously Inaccessible Polyglyoxylates, Rebecca Yardley

Electronic Thesis and Dissertation Repository

Self-immolative polymers (SIPs) are a subclass of degradable polymers that can be triggered to depolymerize when exposed to a specific stimulus. The main advantages of SIPs are the controlled and predictable depolymerization, signal amplification, and tunability of the polymer regarding which stimuli it responds to. The work presented in this thesis details the synthesis, characterization, and applications of two different families SIPs: polycarbamates (PCBs) and polyglyoxylates (PGs). PCBs are known to have depolymerization rates that are sensitive to environmental conditions surrounding them. In efforts to modify the depolymerization, PCB was incorporated into amphiphilic diblock copolymers, first with multi-stimuli-responsive poly(2-(dimethylamino)ethyl methacrylate) …

Progress Toward Durable Icephobic Materials, Matthew J. Coady

Electronic Thesis and Dissertation Repository

Ice accumulation is a major engineering challenge in many fields including aerospace, power generation, transportation, and infrastructure. A variety of solutions are being researched to address this challenge. Perhaps the most promising method of combating ice accumulation is by applying coatings with low values of interfacial ice adhesion strength, τ_ice. Icephobic materials are those with ice adhesion below 100 kPa, and it has been shown that passive delamination can occur on surfaces with τ_ice below 20 kPa. While various low adhesion surfaces have been prepared, durability concerns pervade applications where surfaces experience repeated icing or freeze-thaw cycles, …

Methodologies For Metal Functionalization Of Phosphorus Based Photopolymer Networks, Vanessa Béland

Electronic Thesis and Dissertation Repository

Photopolymer networks with phosphonium cation, alkyl phosphine and olefin functionality were designed, synthesized and functionalized with metals by metathesis, coordination and hydrometallation reactions, respectively. The materials were strategically designed so that the metal functionalization step could be monitored and quantified. In some cases, this involved characterization by IR, NMR, or X-ray spectroscopic techniques, or by comparison to molecular analogues. It was found that by using a bi-functional photopolymer network, the material could be bi-metallized by orthogonal mechanisms. All metallized polymer networks were tested for their suitability as precursors to metal-containing ceramics. The polymers were pyrolyzed, and on analysis it was …

Synthesis Of Crosslinkable Poly(Ester Amide)S For Cell Encapsulation And Delivery, Yu Ting (Natalie) Liang

Electronic Thesis and Dissertation Repository

Tissue engineering using adipose-derived stromal cells (ASCs) shows promise for soft tissue regeneration. Biodegradable polymers are potential biomaterials as they support the growth and delivery of cells. Specifically, poly(ester amide)s (PEAs) are a class of biodegradable polymers with tunable structures that have been shown to exhibit low cytotoxicity and support the growth of various cell types. This thesis involved the development of new water soluble amino acid-based PEAs with crosslinkable moieties to enable formation of hydrogel scaffolds for ASC encapsulation. These hydrophilic phenylalanine-based and alanine-based PEAs were synthesized by solution polycondensation and photo-crosslinked into a series of hydrogels with and …

Photoswitchable Self-Complementary Hydrogen Bond Arrays, Suendues Noori, James A. Wisner

Western Research Forum

Background: Photochromism is the reversible transformation of a chemical material to another form by the absorption of electromagnetic radiation (light), where the two metastable forms have distinct absorption spectra and other properties. Photochromism in materials allows for the switching of their function solely based on irradiation with light. Polymers are used frequently as the building blocks for materials as they are versatile, multifunctional, can carry charge and be processed by solution-based deposition methods. Supramolecular polymers share the same definition as polymers with the exception that they are held together by reversible and directional non-covalent interactions such as hydrogen bonds. Synthesizing …

Development Of In Situ Forming Hydrogels For Intra-Articular Drug Delivery, Andy Prince

Electronic Thesis and Dissertation Repository

Hydrogels are 3-dimensional crosslinked polymer networks that can absorb significant amounts of water. The physical properties associated with hydrogels affords them resemblance to biological tissues making them good candidates for biomedical applications. Many pharmaceuticals, specifically non-steroidal anti-inflammatory drugs (NSAIDs), have poor aqueous solubility, which limits their bioavailability and efficacy. People suffering from chronic osteoarthritis (OA) are required to frequently take large doses to mitigate pain, which can lead to serious side effects. Hydrogels are good strategies to deliver NSAIDs via articular injection because they can form solid gels in situ. This thesis describes the synthesis, formulation, mechanical testing, in …

Plant Stimuli-Responsive Biodegradable Polymers For The Use In Timed Release Fertilizer Coatings, Spencer Heuchan

Electronic Thesis and Dissertation Repository

The use of nitrogen-based fertilizers continues to accelerate with human population growth and increases in global food requirements. Enhanced efficiency fertilizers (EEFs) have been developed to improve the synchronization between nutrient supply and crop nutrient demand. However, many of the current controlled release fertilizers are coated with non-degradable polymers that contribute to accumulation of microplastics within ecosystems. This thesis describes research towards the development of a new class of fertilizer coatings using a self-immolative polymer known as poly (ethyl glyoxylate) (PEtG). PEtG itself does not have suitable properties to produce a viable coating but once blended with another degradable polyester …

Effects Of High Pressure On Photochemical Reactivity Of Organic Molecular Materials Probed By Vibrational Spectroscopy, Jiwen Guan

Electronic Thesis and Dissertation Repository

Chemical transformations of molecular materials induced by high pressure and light radiation exhibit novel and intriguing aspects that have attracted much attention in recent years. Particularly, under the two stimuli, entire transformations of molecular species can be realized in condensed phases without employing additional chemical constraints, e.g., the need of solvents, catalysts or radical initiators. This new synthetic approach in chemistry therefore satisfies increasing need for production methods with reduced environmental impacts. Motivated by these promises, my Ph. D thesis focuses on this state-of-the-art branch of high-pressure photochemistry. Specifically, high pressure is employed to create the necessary reaction conditions to …

The Incorporation Of Phosphorus Into Block Copolymers And Their Self-Assembly, Benjamin F. Hisey

Electronic Thesis and Dissertation Repository

The content of this thesis focuses on the incorporation of phosphorus into amphiphilic block copolymers (BCPs) for the realization of novel properties in the solution phase self-assembled materials derived from the BCPs. The incorporation was achieved through either attaching phosphorus to the terminus of already existing BCPs or the synthesis of novel BCPs from prepared or commercially available phosphorus containing monomers. The phosphorus containing polymers exhibited properties dependent on the existence of the phosphorus species in the BCPs. The first example of this is the modification of poly(ethylene oxide)-b-poly(ε-caprolactone) (PEO-b-PCL) copolymers by the attachment of tetraalkyl …

Glycopolymer Functionalization Of Polymersomes, Josh Jadischke

Electronic Thesis and Dissertation Repository

Carbohydrates are important to cellular communication, recognition, and pathogenesis, making them a useful synthetic target for application in therapeutics and diagnosis. Synthetic carbohydrate presenting scaffolds can replicate or interrupt the binding interactions that occur in nature. Due to the weak nature of the monosaccharide-protein bond, most carbohydrate presenting scaffolds display saccharides in a multivalent manner to improve binding. Recently there has been an effort to combine carbohydrate containing scaffolds with polymersomes (vesicles composed of polymers), due to the structural resemblance of polymersome membranes to biological membranes. This thesis describes the progress towards functionalizing polymersomes with linear glycopolymers as a potential …

Poly(Ethyl Glyoxylate) Solid-Core Particles For Drug Delivery, Michael Thomas Gambles

Electronic Thesis and Dissertation Repository

The ability to trigger the degradation of polymeric nanoparticles (NPs) by a specific stimulus can provide a method of improved drug targeting and selective release capabilities in vivo. The challenge for most polymeric drug delivery systems remains the necessity for many stimuli events to trigger the release of cargo. Polymeric nanotechnology containing “self-immolative polymers” looks to alleviate the reliance on high concentrations of stimuli by undergoing complete end-to-end depolymerization via a single stimulus-mediated reaction of an end-cap. Herein, NPs were developed using poly(ethyl glyoxylate) (PEtG) blended with poly(d,l-lactic acid) (PLA) to encapsulate a hydrophobic cargo to be released upon …

Molecular And Polymeric Materials Based On Asymmetrically Substituted Bf2 3-Cyanoformazanates, Samantha Novoa

Electronic Thesis and Dissertation Repository

This thesis outlines the synthesis and characterization of asymmetric and symmetric 3-cyanoformazanate BF₂ complexes and their incorporation into polymers. CuAAC chemistry was used to synthesize two additional asymmetric BF₂ complexes and a side product that was identified as a symmetric dimer. Spectroscopic and electrochemical properties of these compounds are described.

Incorporation of an asymmetric 3-cyanoformazante BF₂ complex into polymers was done by ROMP. This reaction was used to make homo, block, and random copolymers, where the comonomer was an organic norbornene derivative. Spectroscopic studies of these polymers revealed that, as the mole fraction of BF₂ (ƒ …

Poly(Ethyl Glyoxylate)-Poly(Ethylene Oxide) Nanoparticles: Stimuli- Responsive Drug Release Via End-To-End Polyglyoxylate Depolymerization, Bo Fan, Elizabeth Gillies

Chemistry Publications

The ability to disrupt polymer assemblies in response to specifi c stimuli provides the potential to release drugs selectively at certain sites or conditions in vivo. However, most stimuli-responsive delivery systems require many stimuli initiated events to release drugs. “ Self-immolative polymers” offer the potential to provide amplifi ed responses to stimuli as they undergo complete end-to-end depolymerization following the cleavage of a single end-cap. Herein, linker end-caps were developed to conjugate self-immolative poly(ethyl glyoxylate) (PEtG) with poly(ethylene oxide) (PEO) to form amphiphilic block copolymers. These copolymers were self-assembled to form nanoparticles in aqueous solution. Cleavage of the linker …

Phosphonium-Functionalized Polymer Micelles With Intrinsic Antibacterial Activity, Benjamin Hisey, Paul J. Ragogna, Elizabeth Gillies

Chemistry Publications

New approaches to treat bacterial infections are badly needed to address the increasing problem of antibiotic resistance. This study explores phosphonium-functionalized block copolymer micelles as intrinsically antibacterial polymer assemblies. Phosphonium cations with varying alkyl lengths were conjugated to the terminus of a poly(ethylene oxide)− polycaprolactone block copolymer, and the phosphonium-functionalized block copolymers were self-assembled to form micelles in aqueous solution. The size, morphology, and ζ -potential of the assemblies were studied, and their abilities to kill Escherichia coli and Staphylococcus aureus were evaluated. It was found that the minimum bactericidal concentration depended on the phosphonium alkyl chain length, and different …

End-Capping Strategies For Triggering End-To-End Depolymerization Of Polyglyoxylates, Bo Fan, John Trant, Elizabeth Gillies

Chemistry Publications

Polymers that undergo end-to-end depolymerization in response to the cleavage of a stimuli-responsive end-cap are promising for diverse applications from drug delivery to responsive coatings and plastics. It is critical that the end-cap is designed to respond to an appropriate stimulus for the application. In the current work, end-caps for triggering the depolymerization of poly(ethyl glyoxylate) (PEtG) were explored. First, a phenylboronate, a disulfi de, and an azobenzene were utilized to impart redox-responsive properties to PEtG. Then, methoxy-substituted trityl groups were used to provide sensitivity to mild acid. A multiresponsive platform was also introduced, allowing PEtG to respond to multiple …

Synthesis Of Metal-Containing Phosphines And Their Use In Coordination, Polymer, And Materials Chemistry, Amir Rabiee Kenaree

Electronic Thesis and Dissertation Repository

This thesis describes the investigation of a novel strategy for the synthesis of metal-containing small molecules, polymers, and nanomaterials. In this context, a new family of air-stable, homo- and heterometallic primary, secondary, and tertiary phosphines were prepared via the radical-initiated hydrophosphination reaction of PH₃ with vinylferrocene and/or vinylruthenocene. The full characterization of the phosphines confirmed their targeted structures and proved that the properties of the starting metallocenes are reflected in those of the resulting phosphines.

To study the coordination behavior of this family of phosphines, primary, secondary, and tertiary ethylferrocene phosphines were reacted with Group 6 metal carbonyl adducts …

Creating Functional Materials With Phosphorus, Tyler John Cuthbert

Electronic Thesis and Dissertation Repository

Understanding the relationship between small molecules or polymers and how they affect the properties of materials they compose is the basis of materials science. Using unique and versatile components can impart useful and interesting properties to materials. Here, we aimed to extend this understanding to phosphorus, and the known properties it possesses. This included the production of photopolymerizable coatings containing phosphonium molecules and polymers for antifouling and antibacterial applications. The synthesis and characterization of these phosphonium components was completed and materials were produced utilizing UV curing technology. Addition of these components produced coatings that could resist bacteria attachment and efficiently …

Synthesis Of Metal-Containing Polymers And Stable Organic Radical-Containing Polymers And Their Use As Advanced Functional Materials, Joseph A. Paquette

Electronic Thesis and Dissertation Repository

The work presented in this thesis details the synthesis and characterization of two different families of multifunctional polymers. The first family involved the incorporation of stable 6-oxoverdazyl radicals into polymer scaffolds. This was originally achieved by the polymerization of the radical precursors, phenyl- and isopropyl-6-oxotetrazanes, followed by post-polymerization oxidation to afford the phenyl- and isopropyl-6-oxoverdazyl polymers. A second methodology involved the direct polymerization of isopropyl-6-oxoverdazyl radicals using ring-opening metathesis polymerization (ROMP) to afford polymers with controlled molecular weights and narrow molecular weight distributions. The polymers were characterized by the close comparison of the physical and spectroscopic properties …

Post-Polymerization Functionalization Of Poly (Ethylene Oxide)–Poly (Β-6-Heptenolactone) Diblock Copolymers To Tune Properties And Self-Assembly, Elizabeth Gillies, Brooke M. Raycraft, Jarret Macdonald

Chemistry Publications

Polyester-based amphiphilic block copolymers and their nanoassemblies are of significant interest for a wide range of applications due to the degradability of the polyester block. However, the commonly used polyesters lack functional groups on their backbones, limiting the possibilities to chemically modify these polymers. Described here are new poly(ethylene oxide) (PEO)–poly(β-6-heptenolactone) (PHEL) block copolymers having pendant alkenes at each repeat unit on the PHEL block. First, the self-assembly of these block copolymers in aqueous solution was studied and it was found that they formed solid nanoparticles and vesicles depending on the relative block lengths. Next the alkene moieties of the …

Synthesis, Self-Assembly, And Immunological Activity Of Α-Galactose-Functionalized Dendron–Lipid Amphiphiles, John Trant, Namrata Jain, D. M. Mazzuca, J Trevor Mcintosh, Bo Fan, S M Mansour Haeryfar, Sebastien Lecommandoux, Elizabeth Gillies

Chemistry Publications

Nanoassemblies presenting multivalent displays of biologically active carbohydrates are of significant interest for a wide array of biomedical applications ranging from drug delivery to immunotherapy. In this study, glycodendron–lipid hybrids were developed as a new and tunable class of dendritic amphiphiles. A modular synthesis was used to prepare dendron–lipid hybrids comprising distearylglycerol and 0 through 4th generation polyester dendrons with peripheral protected amines. Following deprotection of the amines, an isothiocyanate derivative of C-linked α-galactose (α-Gal) was conjugated to the dendron peripheries, affording amphiphiles with 1 to 16 α-Gal moieties. Self-assembly in …

Photocontrolled Degradation Of Stimuli-Responsive Poly(Ethyl Glyoxylate): Differentiating Features And Traceless Ambient Depolymerization, Bo Fan, John Trant, Rebecca Yardley, Andrew Pickering, Francois Lagugne-Labarthet, Elizabeth Gillies

Chemistry Publications

The depolymerization of coatings prepared from a 6-nitroveratryl carbonate end-capped poly(ethyl glyoxylate) (PEtG) self-immolative polymer was studied. This polymer undergoes end-to-end depolymerization following cleavage of the end-cap by UV light. Several important fundamental diff erences between this class of polymers and conventional degradable polymers were revealed. For example, polymer backbone cleavage and depolymerization exhibited different dependencies on pH, emphasizing the decoupling of these processes. Probing of the coating erosion mechanism illustrated an interesting combination of features from surface erosion and bulk degradation mechanisms that arise from the end-to-end depolymerization mechanism and further differentiate these polymers from convention degradable polymers. It …

Synthesis, Properties, And Antibacterial Activity Of Polyphosphonium Semi-Interpenetrating Networks, Tyler John Cuthbert, Tristan Harrison, Paul J. Ragogna, Elizabeth Gillies

Chemistry Publications

The development of new approaches to antibacterial surfaces is of growing interest to combat the spread of harmful bacterial infections. Relative to polyammoniums, polyphosphoniums can exhibit enhanced chemical and thermal stability, but have not yet been widely explored for the preparation of antibacterial surfaces. In this work, polyphosphoniums of varying chain lengths were synthesized by reversible addition-fragmentation chain-transfer polymerization of 4-vinylbenzyl derivatives of triethyl, tributyl, and trioctylphosphonium. These polyphosphoniums were then incorporated into semi-interpenetrating networks (SIPNs) based on tetra(ethylene glycol) diacrylate (TEGDA) via a UV light-initiated curing process. Measurements of cure percentage, gel content, water contact angle, and surface charge …

Self-Assembly And Stimuli-Responsive Properties Of Amphiphilic Self-Immolative Block Co-Polymers, Thomas Mackenzie Gungor

Electronic Thesis and Dissertation Repository

In recent years, degradable polymers have become increasingly researched for their applications in drug delivery systems, adhesives, and tissue engineering. Self-immolative polymers (SIPs) are of particular utility due to predictable end-to-end backbone depolymerization after a stimuli-responsive end-cap cleavage. There are examples of incorporating a hydrophobic SIP into an amphiphilic block-copolymer, followed by self-assembly in aqueous media forming various nanoparticle morphologies. However, their self-assembly behaviour has not been described in detail, and there are no general synthetic methods that allow for their synthesis with good control over the relative hydrophilic block ratio, the major factor controlling their morphology. This thesis presents …

Exploring The Chemistry Of Phosphorus For Photopolymer Applications, Ryan Guterman

Electronic Thesis and Dissertation Repository

Prior to this thesis, phosphorus-containing polymers and photopolymerization represented two distinct, non-overlapping fields of study. This thesis examined the prospect of combining these two approaches to create a system possessing the benefits of both techniques. By exploiting the chemistry of phosphorus, and using photopolymerization as a fabrication method, new materials were developed and assessed for their use in various applications.

Among the many phosphorus compounds that may be used in polymer science, phosphonium salts and primary phosphines were of specific focus. First, highly fluorinated phosphonium monomers were developed to create photopolymerized hydrophobic surfaces. A structure-activity relationship was established, as both …

Exploring The Chemistry Of Η5-Cyclopentadienyl-Cobalt-Η4-Cyclobutadiene Containing Polymers; Synthesis, Properties, And Self-Assembly, Mahboubeh Hadadpour

Electronic Thesis and Dissertation Repository

Metal containing polymers (metallopolymers) bring together the synthetic efficiency and versatility of conventional organic polymers with unique redox, responsive, and catalytic properties of inorganic metals. Over the last decade, metallopolymers have gained increased attention because of their unique physical and chemical properties that arise from the incorporation of metal centers into a polymer. Since the first report on a metallocene-based metallopolymer in 1955, there has been growing interest in this class of material. Ferrocene-based metallopolymers represent the vast majority of metallocene containing polymers in the literature. In 1992, the Manners Group established a major milestone in the field of metallopolymers …

Production And Applications Of Formaldehyde-Free Phenolic Resins Using 5-Hydroxymethylfurfural Derived From Glucose In-Situ, Yongsheng Zhang

Electronic Thesis and Dissertation Repository

The phenol-formaldehyde (PF) resin manufacturing industry is facing a growing challenge with respect to concerns over human health, due to the use of carcinogenic formaldehyde and sustainability due to the use of petroleum-based phenol in PF resin manufacture. Glucose and its derivative, 5-hydroxymethylfurfural (5-HMF), have proven to be potential substitutes for formaldehyde in the synthesis of phenolic novolac resins.

This thesis investigated a number of glucose and 5-HMF resin systems including the curing of phenol-glucose novolac resin (PG) with a bis-phenol-A type epoxy. The curing process was modeled according to the Sestak-Berggren equation (S, B) using Málek methods. This was …