Polymer Chemistry Commons^™

Recyclable Composites Prepared From Animal Coproducts And Industrial Waste Sulfur, Perla Y. Sauceda-Oloño

All Dissertations

Pursuing sustainable and environmentally friendly materials has become a significant objective in materials science, particularly flame retardants and construction materials. This dissertation explores the development and evaluation of novel composites and high sulfur-content materials (HSMs) as potential alternatives to conventional, environmentally harmful materials.

Chapter one reviews recent advancements in environmentally benign flame-retardant additives, highlighting the potential of bio-derived phenols, polysaccharide derivatives, and greener phosphorus sources. The review discusses how green additives can enhance the flame retardancy, thermal stability, and smoke suppression properties of various polymers while addressing the challenges and future directions in the field.

Chapter two investigates the production …

Composites Developed By The Reaction Of Elemental Sulfur With Biologically Derived Fats And Oils, Katelyn Tisdale

All Dissertations

Human civilization’s modern infrastructure relies mainly on cement and petrochemical products. However, the production of these building materials have harmful ecological effects such as green gas emissions, therefore intensifying the need to develop alternative, sustainable structural materials from renewably sourced or waste material precursors. The work presented herein investigates various biomass derived resources that serve as the olefin source for reaction with elemental sulfur, another abundant waste source, via inverse vulcanization to form high strength composites competitive with that of traditional building materials.

Chapter one reviews various techniques that have been developed and executed in an effort towards lignin valorization …

Influence Of Glycopolymer Structure On Amphiphilic, Hybrid, Linear Branched Block Copolymer Properties For Use In Biomedical Applications, Kevin Green

Dissertations

The focus of this dissertation is evaluating and adding fundamental knowledge regarding the structure-property relations of glycopolymers used in the design of hybrid block copolymers (HBC) that are cable of self-assembling into delivery vehicles for biomedical applications. A shift to the utilization of natural materials in the design and fabrication of drug-delivery vehicles has garnered significant attention. Understanding the effects of linear glycopolymers content and composition on the resulting HBCs properties can provide valuable insight into how these materials may be tailored for use in targeted biological applications.

The first chapter introduces current literature on the need for improvement in …

Evaluation Of Polymerization Condition Reactions Of Methyl Vinyl Ketone For Hydrogen Storage, Rituborna Ghosh

Theses and Dissertations

Hydrogen is widely regarded as one of the most promising clean alternative fuel sources; however, its widespread adoption has been hindered by significant challenges related to storage and transportation. Various storage methods have been proposed and developed, with continuous advancements being made to address these issues. Among the most effective solutions is the utilization of polymers, which serve as safe and efficient hydrogen storage media. This work investigated the polymerization of methyl vinyl ketone using different ratio of monomer: initiator and monomer: crosslinker using N,N′-methylenebisacrylamide (MBA) as crosslinker and ammonium persulfate (APS) as initiator in a free radical polymerization mechanism. …

Synthesis Of Photocleavable Molecules For Neurological Applications, Nishal Madujith Egodawaththa Arachchilage Don

Theses and Dissertations

In recent biomedical research, the precise control of molecular dynamics through light activation has emerged as a powerful tool, particularly in the field of neurobiology. This approach involves the use of photocleavable cages or photoprotective groups (PPGs) that are chemically tethered to biologically active molecules such as neurotransmitters or calcium chelators. These cages remain inert until exposed to specific wavelengths of light, typically in the visible range, triggering the release of the active compound with high spatiotemporal precision.

For neurotransmitter systems, such as glutamate (Glu), which plays a critical role in synaptic transmission and memory formation, researchers have developed novel …

Solubility Characterization Of Organic Molecules For Aqueous Organic Redox Flow Batteries, Anthony W. Ferrell, Harkeerith K. Vij, Seamus D. Jones

College of Engineering Summer Undergraduate Research Program

The major obstacle to renewable energy sources is a lack of long-term energy storage capabilities. Energy produced during the day dissipates, leaving insufficient electricity for at night. The goal of the project is to design an Aqueous Organic Redox Flow Battery (AORFB) to act as long-term energy storage. Work has been done using machine learning to identify suitable compounds for the batteries. In this work there was no indication as to the aqueous solubility of the molecules; this controls the device’s energy storage capabilities. We used a machine learning model to determine the aqueous solubility of slightly more than 3000 …

The Conservation Treatment And Technical Study Of Two Marisol Sculptures, Ruthie Rolfsmeyer

Art Conservation Master's Projects

ABCDEFG & Hi (1961-62) and Father Damien (1966-67) are both painted wooden sculptures created by Marisol during the height of her fame. Although Marisol is a well-known artist, whose fame has been rekindling since her death in 2016, there have been few technical studies of her works. Multimodal imaging and scientific analysis of these two sculptures provide insight into their structure and materials. Techniques include x-ray radiography, reflectance transformation imaging, x-ray fluorescence spectroscopy, Fourier transform infrared spectroscopy, and pyrolysis-gas chromatography-mass spectrometry. Key findings include the identification of toolmarks, nitrocellulose, alkyd, and acrylic paints, and a genuine diamond and pearl in …

Elevating Commodity Polymers To Advanced Applications In Polymer Photonics And Polymer-Derived Porous Materials, Mark Robertson

Dissertations

Since the inception of synthetic polymers, polymer-derived materials have permeated into essentially all aspects of our daily lives. The most commonly thought of examples of polymer materials involve single-use, disposable products to increase shelf lives of perishable items, act as personal protective equipment, or provide some degree of convenience for the consumer. However, as we have furthered our understanding of polymer chemistry and polymer physics to develop increasingly sophisticated polymer systems, polymer materials have been employed in incredibly advanced applications. These include solid electrolytes for energy storage, matrices for aerospace grade carbon fiber-reinforced composites, membranes for liquid and gas separations, …

Chemical Recycling Of Bio-Based Polyurethane Foams: Evaluating Bio-Based Glycols In Comparison To Petroleum-Based Glycols, Anirudh Thorbole Mr.

Electronic Theses & Dissertations

The paradigm shift towards bio-based polyurethane foams (bio-PUF) has significantly increased post-consumer waste. To address this issue, this research represents a novel approach to enhance sustainable development in the recycling industry by replacing traditional petroleum-based glycols with sustainable bio-based alternatives. This study explores the glycolysis of bio-PUF using bio-based SG-522 glycol and polyethylene glycol (PEG) for comparison. The findings from this research as outlined, reveal no significant differences in depolymerization time between the two glycols, achieving proper depolymerization and high recovery yields of over 95% after solvent purification. Comprehensive FT-IR and NMR analyses confirmed the successful degradation of bio-PUF and …

Castor Oil-Based Polyurethane Adhesives: Effect Of Cross-Linker On The Bond Strength, Mayankkumar Chaudhary

Electronic Theses & Dissertations

Adhesives are important for binding diverse materials, promoting structural integrity and functional versatility in countless daily life applications. An enormous obstacle remains in the development of polyurethane (PU) adhesives exhibiting excellent bonding strength. Designing a chain extender with appropriate molecular structures is critical to improving the bonding strength of PU-based adhesives. In this work, PU-based adhesive was prepared using castor-oil-based polyol (COP) and diisocyanate. The bonding strength of the adhesive was improved by adding chain extenders such as N, N-bis(2-hydroxyethyl) thiophene-2,5-dicarboxamide (ETP) and N, N-Bis(2-hydroxyethyl)-terephthalamide (ETAM). The modified adhesive showed high bonding strength after the addition of chain extenders due …

Synthesis And Analysis Of Borazine Polymers, Kayla M. Besel

2024 Symposium

Plastics and polymers are incredibly useful and ubiquitous in our daily lives but they are incredibly persistent in the environment, killing more than 1.1 million seabirds and animals each year and the global production of plastic has doubled since 1950.¹ A potential path to eliminate this problem is to create polymers that biodegrade or breakdown over time or in certain conditions. Three distinct degradable polymers were synthesized. The synthesis, characterization, and kinetics monitored by UV/Vis over a range of pH’s will be discussed.

1. Derraik, J. G. B. “The pollution of the marine environment by plastic debris: a review” …

Poly(Thioether) Thermosets With Gated Photodegradation, Surabhi Jha

Dissertations

Photodegradable polymer networks are attractive due to the precise spatiotemporal control and large-area applicability of light. Chemical linkages that enable these polymer networks to be photo-responsive, also hinder their applicability in ambient light. Photostable and photodegradable networks have recently been reported to overcome this challenge by combining other stimuli with light for degradation. We report the design of a network that responds to a simultaneous, dual stimulus for photodegradation. We design poly(thioether acetal) networks with benzylidene acetal moieties that are known to undergo β-scission in the presence of free thiols. By blocking these free thiols with a thermally labile protecting …

Thermal Effects On The Voc-Sensitive Polydimethylsiloxane Holographic Gratings, Aleksandra Hernik, Faolan Radford Mcgovern, Patrick Iftime, Izabela Naydenova

Conference Papers

The imperative for monitoring volatile organic compounds (VOCs) emerges from their harmful impact on human health when inhaled excessively over a long term. Polydimethylsiloxane (PDMS), valued for its transparency and excellent flexibility, has already been demonstrated as a promising biocompatible and cost-effective transducer for optical VOCs sensing. Moreover, it facilitates further functionalisation with adsorbing materials to enhance sensitivity and selectivity for specific VOCs detection. We fabricated and examined PDMS-based surface diffraction gratings after exposure to selected VOCs, demonstrating different response for polar and non-polar molecules. Investigated gratings were prepared by replicating sinusoidal surface relief structures inscribed in acrylamide photopolymer using …

Analysis Of The Effect Of Different Surface Preparation Methods On Corrosion Resistance And Adhesion Strength Of Astm A36 Steel Substrate With Surface Tolerant Epoxy Paint As Coating Material, Irwan Wijaya Santoso, Daffa Aqila, Rini Riastuti, Rizal Tresna Ramadhani

Journal of Materials Exploration and Findings

In the industrial world, to extend the service life of materials, protection methods are carried out to slow down the material's corrosion rate. The protection method that is often used is the coating method. The coating method is a protection method by coating the substrate material using a coating material to prevent contact between the substrate material and the environment. In this research, the substrate material used is ASTM A36 steel and the coating material used is Surface Tolerant Epoxy paint. The independent variable used in this study lies in the surface preparation method which consists of: solvent cleaning, hand …

Bio-Based Rigid Polyurethane Foams Using Modified Hemp Seed Oil Combined With Flame Retardants, Sagar Jariwala

Electronic Theses & Dissertations

In today's world, the idea is to synthesize bio-based polyurethane (PU) goods, which reduces reliance on petroleum-based products. As a result, we produced polyol from hemp seed oil (HSO) and evaluated it using FTIR, GPC, hydroxyl value, and acid value. Hemp seed oil polyol (HSOP) was successfully synthesized and combined with additional ingredients such as catalysts, blowing agents, hardeners, and flame-retardant chemicals to produce stiff polyurethane foams. The focus of this research was to synthesize high-quality flame-retardant rigid polyurethane foams (RPUFs) through the addition of flame retardants. The test results revealed that the HSO-based PU without flame retardants has 47.04 …

Hemp-Seed Oil-Based Polyurethane Composite Foam: Effect Of Fillers On The Properties Of Polyurethanes, Mansi Ahir

Electronic Theses & Dissertations

Over the past few decades, polymer composites have been receiving significant interest and become a protagonist due to their enhanced properties and wide range of applications. Herein, the study has been done on the effect of filler and flame-retardant in hemp seed oil-based rigid polyurethane foams (RPUFs) composite performance. First of all, hemp seed oil (HSO) was gone through an epoxidation process using hydrogen peroxide and acetic acid. After that, epoxidized hemp-seed oil (EHSO) was converted into hemp polyol (HSOP) by a ring-opening reaction with methanol. The synthesized HSOP was then reacted with diisocyanate monomer in the presence of commercial …

The Effects Of Free Volume And Processing On The Development Of Gas Separation Membranes, Jacob Schekman

Dissertations

Structure, thermal, mechanical, gas transport, and free volume properties of thiol-ene based systems are investigated and discussed. In the pursuit of generating low energy-cost polymer membranes for gas separation, it became apparent that UV-curing of thiol-ene materials presented several routes toward achieving this goal. Network structure plays a vital role in determining the gas transport properties of membrane materials. UV photopolymerization techniques provide a means to rapidly vitrify network morphologies which can be tuned depending on choice of monomer. Thiol-ene monomers offer a broad range of precursor materials from which to choose for the design of functional membrane materials.

Chapter …

Enabling High-Rate Thermoplastic Composite Manufacturing Through Structure-Processing-Property Relationships Of Polyphenylene Sulfide, Lina Ghanbari

Dissertations

In this dissertation, relationships between polyphenylene sulfide (PPS) chain structure and melt processing parameters are linked to thermoplastic composite (TPC) properties and mechanical performance. Deviations from linear PPS structure and the formation of branching/crosslinked moieties upon exposure to TPC manufacturing steps presents an opportunity to systematically uncover the interdependencies of melt-state thermal history on polymer rheology, crystallization, crystal structure, and translate these properties to the continuum level. This work first explores unreinforced PPS and how the formation of non-linear chain architectures yield altered rheological states when held at melt processing temperatures. These hindered chains exhibit unconventional crystallization behavior and non-uniform …

Structure-Property Relationship Studies Of Electrically Conductive Metal-Organic Framework Materials, Shiyu Zhang

All Dissertations

Electrically conductive metal-organic frameworks (EC-MOFs) are among the most promising materials due to their tunable structures, properties, and diverse functions. However, the lack of comprehensive understanding of their structure-property relationship hinders the development of EC-MOFs. My dissertation focuses on the design, construction, and structure-property relationship studies of EC-MOFs.

Chapter 1 describes how MOFs' structural features and compositions affect the electronic properties and demonstrates conductive mechanisms and the corresponding design strategies to develop EC-MOFs.

Chapter 2 describes the synthesis, characterization, electronic and optical properties of four novel alkali-metal-based (Na, K, Rb, and Cs) 3D-MOFs with continuous tetrathiafulvalene tetracarboxylate (TTFTC) π-stacks, systematicly …

Thermal Frontal Polymerization – Applications In Coatings And Composites, Maria Martinez

LSU Doctoral Dissertations

Thermal frontal polymerization has long been used as a method to cure composites and coatings. However, this is the first time these applications have been used without the use of a catalyst, for the case of composites and coatings.

Chapter 2 discusses how to optimize cure-on-demand, thin layer coatings, using frontal polymerization. Previously, for the use of curing thin layer coating using thermal FP, it was known to just make the formulation viscous enough, as this would prevent premature quenching caused by heat loss. It was discovered that for a given layer thickness, a minimum viscosity and initiator concentration were …