Polymer Science Commons^™

Harnessing Nanocellulose For Sustainable Carbon Capture: Synthesis, Processing, And Performance Evaluation, Jerred C. Wassgren

Doctoral Dissertations

Scientists and governments have recognized the need for environmental remediation, most notably with the adoption of the Paris Agreement in 2016. One of the major concerns is the production of greenhouse gases (GHGs). The major GHG is carbon dioxide (CO₂) in which humans emit over 36 gigatons yearly. Atmospheric CO₂ is responsible for 60% of the heat retained by the earth – resulting in rising temperatures, melting ice caps, and increasing ocean acidification. Therefore, a major goal of the Paris Agreement was to reduce GHG emissions as well as the capture of CO₂ from the atmosphere. …

Robust Gasification Trial Results For A Variety Of Difficult-To-Recycle Packaging-Related Materials, Bruce A. Welt

Journal of Applied Packaging Research

Currently, recycling requires nearly absolute sorting of materials to accommodate the limited capabilities of existing recycling infrastructure. Whether a material is “recyclable” depends more on the method of recycling than the material itself. Our dependence upon sorting has limited success of recycling and has stifled our ability to achieve circular economy sustainability with plastic packaging materials. Our dependence upon sorting is rooted in our material-specific recycling processes. However, newer robust recycling processes are commercially available that reduce or eliminate the need to sort waste, and can convert mixed waste into primary feedstock chemicals, such as methanol for subsequent manufacture of …

The Development Of An Advanced Biorefinery To Produce Cellulosic Sugars And Bionanomaterials, Carlaile Fernanda De Oliveira Nogueira

Electronic Theses and Dissertations

Market trends show growing interest in cellulose nanomaterials due to their low environmental impact. However, current nanocellulose isolation technologies face technoeconomic and life cycle limitations. Previous research has shown that enzymatic treatments effectively reduce the energy input for mechanical nanocellulose isolation. Simultaneously, there is potential to improve the viability of cellulosic ethanol facilities by coproducing nanocelluloses as high-value product obtained from agricultural feedstock. Here, our goal was to study the mass balance of enzymatic-mechanical processes that coproduces cellulosic sugars and nanocelluloses, evaluating the technical feasibility of converting lignified and non-lignified materials.

First, we have determined a feasible 50:50 mass ratio …

Advances In Cellulose Nanomaterial-Based Foams For Environmental Applications, Md Musfiqur Rahman

Electronic Theses and Dissertations

The use of metal-oxide nanoparticles adsorbents is limited to fixed-bed columns in industrial-scale water treatment applications. This limitation is commonly attributed to the tendency of nanoparticles to aggregate, the use of non-sustainable and inefficient polymeric resins as supporting materials, or a lack of adsorption capacity. Foams and aerogels derived from cellulose nanomaterials have unique characteristics, such as high porosity and low density, which enables their use in a variety of environmental applications, including water treatment. However, the overall use of cellulose nanomaterial-based foams in various environmental sectors is limited due to the high cost of production associated with time- and …

Using Afm-Ir To Study Nanoscopic Phase Behavior Of Polymer Blends And Photovoltaic Bulk Heterojunctions, Nathaniel L. Prine

Dissertations

Conjugated polymers (CPs) and polymer blends harbor the potential for high-performance organic solar cells (OSCs) due to their short energy payback time, low cost, solution processability, lightweight attributes, and flexibility. However, OSCs suffer from poor thermal stability compared to their inorganic equivalents. This study explores the thermal instability of OSCs, focusing on phase separation of the photoactive layer under heat, resulting in morphology changes and degradation of power conversion efficiency (PCE). Utilizing atomic-force microscopy coupled with infrared spectroscopy (AFM-IR) and differential scanning calorimetry (DSC), we delve into thermal stability-morphology relationships to devise strategies to improve OSC blend durability under thermal …

Development Of Lignin-Based Copolymers And Polymer Blends, David Chem

Graduate Theses and Dissertations

Increasing industrial interest in reducing fossil fuels in virgin polymer production and incorporating bio-based polymeric materials has led researchers to explore the potential of utilizing plant-based polymers such as lignin. Chapter 1 of this thesis presents a comprehensive overview of copolymerization and blending techniques for lignin and synthetic polymers, emphasizing different types of modifications and copolymerization techniques as well as key parameters such as temperature, reaction time, pH level, and solution compositions. These valorization methods are directed towards the development of high-value lignin-based materials with properties well-suited for various commercial applications. Chapter 2 offers a fundamental exploration into the amination …

Characterization Of Interlayer Laser Shock Peening During Fused Filament Fabrication Of Polylactic Acid (Pla), Fabien Denise

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

The field of additive manufacturing (AM) has gained a significant amount of popularity due to the increasing need for more sustainable manufacturing techniques and the adaptive development of complex product geometries. The problem is that AM parts routinely exhibit flaws or weaknesses that affect functionality or performance. Over the years, surface treatments have been developed to compensate certain flaws or weaknesses in manufactured products. Combining surface treatments with the modularity of additive manufacturing could lead to more adaptable and creative improvements of product functions in the future. The current work evaluates the feasibility of pursuing a new research axis in …

Optimizing Channel Formation In Peg Maleimide Hydrogels, Bakthavachalam Kannadasan

Masters Theses

Blood vessels including the arteries, veins, and capillaries are a critical and indispensable component of various organisms. Some studies estimate that if all the blood vessels present in our body are arranged in line, they would amount to a total length of approximately 60,000 miles. This distance is enough to circle the world two and a half times! In addition to being all pervasive, blood vessels perform certain key functions such as delivery of oxygen and nutrients to various tissues in the body. They also assist in the spread of diseases such as cancer. Therefore, it is important to study …

Machine Learning Modeling Of Polymer Coating Formulations: Benchmark Of Feature Representation Schemes, Nelson I. Evbarunegbe

Masters Theses

Polymer coatings offer a wide range of benefits across various industries, playing a crucial role in product protection and extension of shelf life. However, formulating them can be a non-trivial task given the multitude of variables and factors involved in the production process, rendering it a complex, high-dimensional problem. To tackle this problem, machine learning (ML) has emerged as a promising tool, showing considerable potential in enhancing various polymer and chemistry-based applications, particularly those dealing with high dimensional complexities.

Our research aims to develop a physics-guided ML approach to facilitate the formulations of polymer coatings. As the first step, this …

Engineering Of Functionalized Carbon Nano-Onions Embedded Bsa Nanocomposite Fibers For Stimuli-Responsive Drug Release, Ramiro Manuel Velasco Delgadillo, Narsimha Mamidi

Research Symposium

Background: Advanced drug delivery systems (DDSs) have received enormous attention in biomedical applications due to their pharmacodynamic and pharmacokinetic drug properties. For the present study, poly 4-hydroxyphenyl methacrylate (PHPMA)/CNOs (f-CNOs) inserted bovine serum albumin (BSA) nanofibers were prepared for stimuli-responsive release of Doxorubicin (DOX). Temperature and pH would be altered to study the release of DOX in acidic microenvironments.

Methods: PHPMA were coupled with COOH-CNOs via ester coupling via the sonochemical method to produce PHPMA-CNOs (f-CNOs). Then, f-CNOs/DOX embedded BSA nanofibers were prepared at room temperature using Forcespinning. UV spectra of DOX-loaded nanofibers were studied to investigate the …

Investigating The Rheological Behavior Of A Simple Yield Stress Fluid Under Shear Flows, Francesco Accetta

Theses

Many soft materials display unique and complex rheological behavior characterized by a transition from a solid-like to a fluid-like state upon the application of a force that exceeds the threshold to flow, known as the yield stress. Yield stress fluids are found in a wide range of commonly encountered materials including microgels, emulsions, and foams, and have been widely studied by rheologists over the last several decades. Carbopol is a popular polymeric microgel system as it displays simple, non-thixotropic rheological behavior and is typically seen as an ideal yield stress fluid. Previous research has demonstrated the reproducible behavior of shear …

Retracted: Fabrication And Characterization Of Wood Fiber Reinforced Polymer Composites, Firoz Ahmed, Omar Faroque, Saif Hasan, Khan Rajib Hossain, Rezaul Karim Sheikh

Al-Bahir Journal for Engineering and Pure Sciences

Wood-polymer composites (WPCs) combine the properties of wood and polymers. Creating composites involves adding plant or wood fibers as fillers to a polymer matrix. This study used mahogany and mango wood sawdust as reinforcement materials, while high-density polyethylene (HDPE) and polyvinyl chloride (PVC) were used as matrices. The investigated data in this study comprises four different (10, 20, 30, and 40) weight percentages (wt%) of mahogany and mango sawdust paired with corresponding wt% (90, 80, 70, and60) of HDPE and PVC matrices. The extrusion method produced composites with different amounts of sawdust and polymer matrices. Wood polymer composites were characterized …

Designing Bioinspired Materials With Tunable Structures And Properties From Natural And Synthetic Polymers, Anandavalli Varadarajan

Theses and Dissertations

Biological systems are composed of complex materials which are responsible for performing various functions, such as providing structural support, mobility, functional adaptation to the environment, damage repair, and self-healing. These complex materials display excellent mechanical properties and can rapidly adapt to external stimuli. Thus, nature inspires in terms of source materials, functions, and designs to develop new-generation structural and functional materials. Polymers (natural or synthetic) are excellent sources of developing materials to mimic the functions of soft segments in biological systems. This dissertation focuses on synthesizing and characterizing two different materials with tunable structures and properties: complexes from natural polysaccharides …

Elucidating Self-Assembly Of Semiconducting Polymers In The Presence Of A Low Molecular Weight Gelator, Madhubhashini Lakdusinghe

Theses and Dissertations

Semiconducting polymers with a conjugated backbone are important for energy storage, conversion, and biomedical field applications. The self-assembly process of these polymers in solutions depends on the polymer concentration and quality of the solvent. The electrical properties of thin films obtained from the solution phase depend on the self-assembled process. Thin films of conjugated polymer gels with percolating networks of self-assembled structures display improved electrical conductivities. In this dissertation, we studied the impact of the secondary gel matrix formed by a low molecular weight gelator, on the self-assembly of conjugated polymers, the preservation of assembled structures in dried gel films …

Improving Lignin Recovery From Paper Mill And Biorefinery Waste Streams Via Liquid-Phase Splitting, Carter Fitzgerald

All Dissertations

Lignin is an abundant biopolymer with significant promise due to its aromaticity. It has been targeted as a replacement for a number of petroleum-based products including adhesives, coatings, polyurethane foams, activated carbon, and carbon fibers. However, commercially available bulk lignins are too polydisperse, and contain too many residual metals from the pulping process that are detrimental to the properties of the final product.

The Sequential Liquid-lignin Recovery and Purification (SLRP) process was developed by Michael Lake and John Blackburn, in collaboration with Clemson, with the intention of creating a continuous method for recovering lignin from paper-mill black liquors. Thies and …

Characterization Of Mechanically Recycled Polylactic Acid (Pla) Filament For 3d-Printing By Evaluating Mechanical, Thermal, And Chemical Properties And Process Performance, Mahsa Shabani Samghabady

All Theses

Polylactic acid (PLA) is a biopolymer made from renewable resources such as sugar and corn. PLA filament is a popular material used in Fused Deposition Modeling (FDM) 3D-printing. While this material has many advantages, all the failed parts, support structures, rafts, nozzle tests, and the many prototype iterations during the 3D-printing process contribute to the plastic pollution and release of greenhouse gases. Although PLA is biodegradable, it can take years to degrade in landfills. Instead of throwing away PLA waste and buying new filaments, PLA can be recycled. Amongst the different recycling technologies, mechanical recycling is the most environmentally friendly. …

The Biological Activity Of Dual-Responsive Glycopolymers For Intracellular Codelivery Of Antigen And Lipophilic Adjuvant, Micaela Shields

Honors Theses

Subunit vaccines present themselves as an attractive alternative to traditional approaches to vaccines, which utilizes whole organisms to trigger an immune response. While these traditional approaches have proven themselves reliable within the history of vaccinations, they generally deliver subpar robust cellular-mediated immunity and pose many safety risks. Composed of proteins and /or peptides, subunit vaccines are safer and more precise alternatives to traditional approaches. However, the pharmacokinetic properties of the macromolecules that make up these vaccines hinder the subunit vaccine’s level of immunogenicity [d1] Examples of this hindrance include but are not limited to aggregation at the injection site and …

The Influence Of Heat And Mass Transfer On The Setting Rate Of Adhesives Between Porous Substrates, Mubarak Mohammed Khlewee

Electronic Theses and Dissertations

The dynamic penetration of fluid into a porous media where other changes are occurring such as temperature or concentration is of interest to a number of situations. However, little experimental and theoretical analysis of this situation is found in the literature where most of the previously published works have studied the penetration with constant physical properties, where there is no change of the fluid as it enters the pores. This situation is important in the setting of adhesives in porous medium such as in the setting of hot melt and water-based adhesives in the production of paper based packaging. The …

Enhancing Compatibility And Mechanical Properties Of Natural Rubber Composites, Krisma Yessi Sianturi, Adam Febriyanto Nugraha, Belle Kristaura, Mochamad Chalid

Journal of Materials Exploration and Findings (JMEF)

Pure natural rubber (NR) exhibits low mechanical properties, necessitating the incorporation of additives like vulcanizing agents and fillers. Carbon black and silica, conventional fillers, are relatively expensive and not environmentally friendly. This study explores using Oil Palm Empty Fruit Bunch (OPEFB) fiber as an affordable, abundant, and biodegradable alternative filler for NR. However, compatibility issues arise between the nonpolar NR and the polar OPEFB fiber. A latex-starch hybrid coupling agent (CA (NR-St)) was added to the composite formulation to address this. NR, OPEFB fiber, and the coupling agent were mixed using an open roll mill with a 10 phr OPEFB …

Characterization Of Lignin And Cellulose Biopolymers Structure – Function Relationships, Zachariah Pittman

All Dissertations

Biomass is vital to ongoing efforts to secure a sustainable future. While many of our efforts focus on finding alternative forms of energy, biomass among them, only biomass has the potential to serve as a sustainable materials feedstock. However, biomass is heterogenous, complicating the upgrading processes needed to manufacture commodity and performance products. For example, plant biomass consists largely of cellulose, a crystalline polysaccharide, and lignin, a highly stable polyaromatic. The specific properties of cellulose and lignin depend greatly on the plant, harvesting conditions, and isolation procedures. Thus, accurate and reliable determination of the fundamental properties of biomass is crucial …

Elucidating The Mechanical And Transport Properties Of Lignin-Based Hydrogel Composites, Nicholas Gregorich

All Dissertations

The use of lignin in the fabrication of soft composites has become an emerging area of research in polymer science and polymer chemistry. These lignin-based materials present numerous benefits, notably, a reduction in the use of petroleum-based precursor, improved structural benefits to otherwise soft host polymers, as well as the inherent antimicrobial and antioxidant properties of lignin, making it suitable for biomaterials. Herein, we present two chemical reaction pathways of incorporating lignin that was fractionated and cleaned using the Aqueous Lignin Purification with Hot Agents (ALPHA) process into poly(vinyl alcohol) (PVA) hydrogel composites for aqueous-based separations. By leveraging the ALPHA …

Bridging The Gap Between Phase Behavior And Processing For Renewable And Refinable Carbonaceous Precursors, Graham Tindall

All Dissertations

As a category of materials, engineered carbons, specifically carbon fibers, are first-in-class for properties such as modulus, specific strength, and thermal resilience; however, the inability to directly process atomic carbon necessitates the development and optimization of carbonaceous precursors. Because the structure and properties of carbon are highly dependent on the precursors and requisite processing, numerous materials have been investigated as feedstocks for large-scale production. Although cellulose and rayon were among the first investigated, polyacrylonitrile (PAN) is the current hegemon of carbon fiber precursors. PAN feeds 90% of this market, but it is neither inexpensive nor renewable. Because a significant fraction …

Chloramine Devulcanization Of Waste Rubber., Patrick Kroeger

Electronic Theses and Dissertations

The disposal of waste rubber, particularly tire rubber, continues to pose a challenge in the 21st century. As a result, most end-of-life tires (ELTs) are either dumped in landfills or burned as tire-derived fuel. Chloramine devulcanization may offer a viable solution to this problem. Chloramine devulcanization is a low-temperature, low-pressure, process that selectively breaks sulfur crosslinks while preserving the polymer backbone. Chloramine devulcanization enables the recovery of chloramine recovered carbon black (CrCB) and devulcanized rubber (CdR) as separate products. Initial analysis of CdR revealed that it was formable and malleable, suggesting that crosslinking was absent. Spectroscopy showed that CdR contained …

Lignin Copolymer Property Prediction Using Machine Learning, Collin Larsen

Chemical Engineering Undergraduate Honors Theses

Lignin, an abundant biopolymer, is a waste byproduct of the paper and pulp industry. Despite its renewable nature and potential applicability in various products, such as plastics and composites, the development of lignin-based materials has been impeded by the cumbersome, Edisonian process of trial and error. This research proposes a novel approach to forecasting the properties of lignin-based copolymers by utilizing a recurrent neural network (RNN) based on the Keras models previously created by Tao et al. Example units of modified lignin were synthesized via esterification and amination functional group modifications. To increase the efficiency and accuracy of the prediction …

Removal Of Hexavalent Chromium From Water By Chitosan-Enhanced Ultrafiltration, Putu A. Y. Indiasih, Anindita D. Syaifudin, Nurul Faiqotul Himma, Bambang Ismuyanto

Makara Journal of Technology

Polymer-enhanced ultrafiltration has gained increasing attention as a selective separation process to remove small solutes, such as metal ions, from water or wastewater. Hexavalent chromium Cr(VI) is one of the metal ions in wastewater that has received considerable attention because of its toxicity. Chitosan was used in this study as the polymer to bind Cr(VI) to enhance its removal by ultrafiltration. The effects of chitosan-to-Cr(VI) ratio on Cr(VI) rejection and permeate flux were investigated. In addition, the fouling tendency was evaluated. Results showed that the addition of chitosan with a mass ratio of 12.5 increased the Cr (VI) rejection from …

Poly(Ether Imide)S: Synthesis And Properties, Rachel Price

Honors College Theses

The synthesis of strong polymers is crucial to the creation of heat-resistant, durable, and mechanically useful plastics that we use every day. Poly(ether imide)s are used in applications such as food service, aerospace, automotive, and many more. This thesis will discuss the synthesis and properties of these plastics to help express a larger understanding of these polymers.

Polyesters Derived From Biobased 1,5-Pentanediol For Coatings, Adhesives, And Biodegradable Plastics, Lei Zheng

Doctoral Dissertations

Biomass-derived polymers are drawing increased attention from researchers due to unique performance attributes, potential for biodegradability, new low-cost feedstocks, and improved sustainability. Biobased feedstocks are employed in both major applications of polymers thermosets and thermoplastics. For thermoset coatings and adhesives, biobased resins such as biobased alkyds, epoxy resins, benzoxazine resins, starch derivatives, and proteins from plants and animals, are promising candidates to replace petroleum-derived counterparts. Thermoplastics such as polyethylene are mainly produced from fossil resources, generally have poor degradability and are difficult to effectively recycle. Currently, in the United States, less than 10% plastics are recycled, and more than 70% …

Polymer Based Energy Storage And Thermal Management On Textile Devices, Wesley A. Viola

Doctoral Dissertations

Humans developed textiles to manage thermal energy transfer with the environment and support homeostasis in a wide range of climates. With the anticipation of wearable technologies to transform healthcare via early, pre-symptomatic detection of illness, there is now a demand for electrical energy storage to support such on-body devices. Finding energy materials to merge seamlessly with textiles is basic requirement to ensure widespread adoption of wearable health monitors. Here we use a vapor deposition process to conformally coat ordinary fabrics with the doped conjugated polymer poly(3,4 ethylenedioxythiophene) (PEDOT-Cl), a soft material which possesses electronic and redox capabilities. We demonstrate PEDOT-Cl …

Effect Of Chemical Identity And Morphology On Amphiphilic-Zwitterionic Block Copolymer Membranes, Ria Ghosh

Doctoral Dissertations

Amphiphilic block copolymers have gained a broad research interest attributed to their self-assembly properties over a range of pH, temperature, and ionic strength. Polyzwitterions have attracted special attention due to their hydrophilicity, charge sensitivity and coulombic attraction of the opposite charges over a range of environments making them a popular material of study in the field of stimuli responsive systems, for example in self-healing hydrogels, and water transport membranes. Combining the stimuli responsiveness and higher hydrophilicity of zwitterionic polymers with self-assembly behavior of amphiphilic block copolymers created an interest to study the effect of composition and identity of the zwitterionic …

Effect Of Process Parameters On The Mechanical Properties Of Carbon Fiber Epoxy Composites By Wet Compression Molding, Saboora Ayatollahi

Electronic Thesis and Dissertation Repository

In recent years, due to growing environmental concerns, composite materials have emerged as a promising lightweight alternative for metals in structural applications in automobiles. Among composite manufacturing processes, Wet Compression Molding (WCM) is a new method of producing Carbon Fiber Reinforced Polymer (CFRP) components. For similar processes like RTM, operating conditions are always one of the factors that impact the mechanical performance of CFRP parts. Thus, this thesis aimed to investigate the effects of operating conditions, including resin temperature, mold temperature, resin set time, gap closure speed, and mold curing time on the mechanical property of the composite parts. In …