Polymer Chemistry Commons^™

Atom Economical Reactions Of Terpenoids And Post-Consumer Plastics With Sulfur, Charini Maladeniya

All Dissertations

The production of Ordinary Portland Cement (OPC) and its uses have a complicated environmental impact, which is influenced by infrastructure development and building operations as well as CO₂ emissions, which account for 7% of all worldwide CO₂ emissions. Due to the increasing population, production is still ongoing. The search for cement and construction materials produced with zero to low CO₂ emissions is therefore continuous. Finding recyclable, CO₂ gas-free biocomposites with high sulfur content that can rival the mechanical properties of popular building supplies like Portland cement is the primary objective of the research discussed in this …

Poly(Ionic Liquid)S For Magnetic, Ionic, And Electrical Stimuli-Responsive Applications, Kayla Ann Foley

Graduate Theses and Dissertations

Poly(ionic liquid)s (PILs) are a fascinating subclass of strong polyelectrolytes formed from polymerizable ionic liquids. As a result of their unique properties and counterion exchangeability, PILs can exhibit conformation structure or material property changes in response to external stimuli such as changes in pH/ionic environment, magnetic fields, and electric potentials. In Chapter 1, a comprehensive review of PILs design as well as their stimuli-responsive behavior is provided. Additional motivation for each dissertation chapter is also discussed. In Chapter 2, magnetically responsive PILs (MPILs) are developed from complexing paramagnetic salts with a random PIL copolymer containing a metal-coordinating co-monomer, acrylamide. A …

The Emergence Of Zerovalent Carbon Compounds From Structural Curiosities To Organocatalysts, Allegra L. Liberman-Martin

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Low-valent main group compounds have reactivity patterns and properties reminiscent of transition metals. While divalent carbon compounds such as carbenes are widely studied ligands and organocatalysts, zerovalent carbon species have received considerably less attention. This perspective highlights the properties and reactivity of zerovalent carbon compounds, focusing on their first applications as organocatalysts for small molecule reduction and polymerization reactions.

The Effect Of Heat Treatment And Chemical Treatment On Natural Fibre To The Durability Of Wood Plastic Composites – A Review, Nuratiqah Asyiqin Mohd Nasharudin, Nur Fatihah Sulaiman, Nurul Aziemah Mohammad, Wan Nor Raihan Wan Jaafar, Falah Abu Dr., Siti Norasmah Surip

Journal of Materials Exploration and Findings

The application of WPC is not only limited to indoor applications but has been extended to exterior applications where properties of WPC could compromise during service life. WPC was derived from wood fiber of various sizes to reinforce polymers. Wood fiber has the advantage of a cheaper price, being abundantly available, and ease of processing, however, the critical factor is its hydrophilic nature, where moisture absorption is likely to occur. Thus, treatments for reducing the hydrophilicity of wood fibers are applied. By treatment of wood fiber, the surface impurities were removed, leaving the roughened surface of fibers, thus providing a …

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, …

Dynamical Polymer Chain Heterogeneities And Their Impacts On The Glass Transition, William Forrest Drayer

USF Tampa Graduate Theses and Dissertations

The utilization of polymeric materials has endured since prehistory, at first unknowinglyin the form of natural biopolymers such as wood and leather, culminating and continuing through the development of the plastics industry in the early twentieth century. Polymers, along with other materials including silicate glasses, readily exhibit the glass transition upon quenching: a continuous but rapid change from viscous (liquid) to elastic (solid) behavior. The physics surrounding the glass transition have been studied for over a century; while considerable progress has been made, there remains no universally accepted predictive theory of the glass transition. Modern development of glassy materials consists …

Development Of Graphene And Graphene Derivative Advanced Functional Additives: Mechanism And Application In Asphalt Formulations And Thermal Interface Management Materials, Dana Pinson

Dissertations

The overarching focus of my research is the use of graphene and graphene derivatives to enhance polymer properties. My first focus area was the prevention of oxidative degradation of asphalt through the incorporation of a graphene oxide (GO) -based nanoparticle filler to enhance oxygen barrier properties. Primary amine terminated polyisobutylene was synthesized via cationic polymerization followed by post polymerization chain end modification in a range of molecular weights and covalently grafted via the primary amine to graphene oxide aerogel (aGO) to create a polyisobutylene grafted graphene oxide (PIB-g-GO) nanoparticle. PIB-g-GO was then mixed into a substitute asphalt matrix at various …

Supramolecular Design Of 3d-Printable Hydrogels For Functional Materials, Miao Tang

Dartmouth College Ph.D Dissertations

Additive manufacturing, more commonly known as 3D-printing, is bringing about a grand technological transformation in material design and fabrication. In contrast to traditional fabrication techniques, 3D-printing features rapid prototyping, complex and customized 3D structural designs, and multi-material integration. Among current 3D-printing systems, direct-ink-writing (DIW) exhibits unique functionalities due to its mild operation conditions and the ability to integrate various organic and inorganic entities. Although supramolecular binding motifs are increasingly utilized in 3D-printing designs, the optimization of 3D-printable inks remains largely empirical. In this thesis, we present two strategies to rationally design supramolecularly crosslinked 3D-printable hydrogels, including (1) micro-crystallization and (2) …

Covalent Adaptable Networks For Wood Coatings, Jachin Boaz Clarke

Materials Engineering

Wood swells and shrinks causing problems with seasonal humidity. Applying thick coatings of reactive finishes based on cross-linked polyurethane, epoxy, or polyesters can slow moisture-vapor exchange. However, the use of thick coatings leads to cracking and crazing sooner than thin finishes. This research proposes the addition of 3.3 mol % triazabicyclodecene, a conventionally used covalent adaptable network catalyst, in a commercially available polyester-based wood coating. The self-healing of the wood coating is tested using DMA stress relaxation and compression molding. The result from DMA renders inconclusive and compression molding indicates the novel wood coating oxidizes at elevated temperatures. The wood …

Analysis Of Polymer-Coated Bullets Using Spectroscopic Methods, Liana R. Albano

Student Theses

Polymer-coated bullets have gained popularity because they can reduce the user’s exposure to heavy metals in the ammunition. The synthetic jacket, which surrounds the lead core, is advantageous because it prevents metal-on-metal contact between the bullet and the bore. A challenge for firearms identification is that polymer-coated bullets do not retain unique markings that can be used to identify the gun, the way standard metal-coated bullets do. However, metal-coated bullets will result in a similar challenge if the bullet is too deformed once it is recovered. Another issue is that the composition of the polymer coating was never disclosed by …

The Effect Of The Carbon Nanotubes’ Surface Area On The Morphology And Performance Of Cellulose Acetate Nanocomposite Membranes In Nanofiltration Applications, Nouran Elbadawi

Theses and Dissertations

Population increase and climate change have significantly affected the availability of fresh water for consumption. Studies by UNESCO showed that more than 28% of the world population didn’t have access to clean safe drinking water in 2020. This situation is expected to get more serious over the coming 30 years with the limited availability of natural fresh water sources. The need to find solutions from alternative non-freshwater resources for drinking or irrigation is becoming a necessity. Within the context of desalination technologies, thousands of investigations are conducted to find the cheapest most efficient way of water treatment aiming at expanding …

Sunflower Oil-Based Wood Adhesive With High Mechanical Strength And Enhanced Bonding By Introducing Fillers, Arjun Chaudhari

Electronic Theses & Dissertations

Petroleum-based compounds are generally utilized in industries for getting higher mechanical strength for wood application, where the process of synthesis releases toxins into the environment and causes health issues.

Because of this, scientists are trying to make biobased compounds and products. In this research, sunflower polyol was used to make polyurethane (PU) resin. For the formation of polyol, an epoxidation reaction followed by a ring-opening reaction was performed. The presence of hydroxyl groups was confirmed using Fourier transform infrared spectroscopy (FT-IR) and hydroxyl value determination test to confirm the polyol formation. After that, hydroxyl groups of polyol were reacted with …

Effect Of Graphene-Based Fillers On The Properties Of Sunflower-Based Polyurethane, Vishwa Suthar

Electronic Theses & Dissertations

Polyurethane market majorly depends on synthetic materials which are noxious. This stimulated an idea to replace petrochemical resources with renewable resources for polyurethane production. Keeping this in mind, this research focused on the use of sunflower oil for the preparation of polyol and its use in polyurethane composition. The reaction mechanism of epoxidation and ring-opening was approached for the conversion of sunflower oil to polyol. During the conversion of sunflower oil, unsaturated groups of sunflower oil were converted into hydroxyl groups of polyol.

Sunflower oil-based polyol was successfully blended with methylene diphenyl diisocyanate (MDI) to form urethane bonds. Confirmative tests …

Evaluation Of Promising Eco-Friendly Flame Retardants For Bio-Based Rigid Polyurethane Foams Based On Modified Castor Oil, Prasadi Abeysinghe Arachchilage

Electronic Theses & Dissertations

Fossil fuel derivatives in the polyurethane industry are gradually being replaced with environmentally friendly alternative bio-based resources. Vegetable-oil-based polyols are emerging bio-based resources that can decrease cost competitiveness in polyurethane markets, reduce environmental impacts, and meet the urgent need for green and sustainable development strategies. Among this, interest is the use of castor oil to make polyurethane because of its inedibility and the fact that it contains many functionalizable chemical groups. However, the poor thermal stability and low load-bearing capacity of castor-oil-based rigid polyurethane foam limits its application. Two methods were used to address these limitations: (i) more hydroxyl groups …

Optimizing Process Conditions And Characterizing Elastomeric Properties Of Immiscible Polymers For 3d Printing Applications, Matthew Long

Electronic Theses & Dissertations

Within recent years, 3D printing within the plastics and polymer industries has becoming increasingly prevalent. Also known as additive manufacturing, 3D printing enables the creation of rapid prototypes for short production runs without the need for complex tooling. This allows for runs that are shorter and lower in cost than conventional processes. Polylactic acid (PLA) is a thermoplastic that is widely used in 3D printing for its mechanical properties and low cost. The qualities of PLA however are lacking in the areas of flexibility and toughness which is required in many prototyping scenarios. The solution to this is to incorporate …

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

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 …

Separation Of Organic Acids Through Direct Catalysis From Sugars, Katelyn Robinson

Chemical Engineering Undergraduate Honors Theses

Society relies on plastic products, whether they are single use or durable. A downside of plastic is that the most common type is a product of oil and oil is not only a limited resource but also a climate-damaging resource. Polylactic acid (PLA) is a bio-based, biodegradable plastic. However, the process of converting biomass to polylactic acid polymer has the largest environmental impact of the PLA production process, so alternative methods of conversion are needed (Moretti et al., 2021). The polylactic acid polymer can be made with lactic acid, which can be converted from glucose.

Dpd Guided Insight On The Formation Process Of Polyethersulfone Membranes By Nonsolvent Induced Phase Separation And The Effects Of Additives, Eric Ledieu

Graduate Theses and Dissertations

Dissipative particle dynamics (DPD), a coarse grain simulation method, was applied to the membrane formation process of non-solvent induced phase separation (NIPS) to gain further insight on the mechanism of certain variables and how they affect the final morphology. NIPS involves two solutions, an organic polymer dissolved in an organic solvent colloquially called the dope and an aqueous coagulation bath, brought into contact with one another. The solvents then mix, causing the polymer to fall out of solution as an asymmetric membrane with a dense surface layer and a more open subsurface layer in response to the decreasing solubility. Polyethersulfone …

The Influence Of Diamine Curing Additives On The Network Architecture Of Phthalonitrile Thermosetting Polymers, Tyler J. Richardson

Dissertations

Phthalonitrile monomers undergo diamine-promoted polymerization by a complex reaction mechanism involving two competitive cure pathways, forming two primary network architectures: linear polyisoindoline chains and branched triazine crosslinks. The influence of the diamine curing additive on the polymerization pathway, and the influence of the resulting network architectures on cured network properties, have not been adequately explored within the phthalonitrile field. Two structurally different diamine curing additives, bis[4-(3-aminophenoxy)phenyl] sulfone (mBAPS) and 1,3-phenylenebis((4-(4-aminophenoxy)phenyl)methanone) (AEK-134), were studied for the polymerization of resorcinol phenylphosphate phthalonitrile (RPPhPN), where the influence of diamine structure and concentration on the polymerization behavior, network architecture, and bulk thermal and thermomechanical …

New Alkyd Resins From Underutilized Indigenous Seed Oils: Synthesis And Characterization, Aliru O. Mustapha, Hakeem B. Ayoku, Halimah A. Amao

Karbala International Journal of Modern Science

The underutilization of sesame (Sesamum indicum L.), sweet almond (Prunus amygdalus), and jatropha (Jatropha curcas) seeds indicates a significant resource waste. Nine different varieties of 25% (short), 40% (medium), and 60% (long) alkyd resins were produced from the cross-section of drying, semi-drying, and non-drying oils. A large amount of conversion occurred, with the extent of the reaction (Pav) decreasing as time progressed and the corresponding increase in alkyds' average degree of polymerization (Dp) showing synthesized alkyds. Surface drying from the set-to-dry and dry-through periods climaxed at 2 hours for all the alkyds. Except for alkali, synthesized alkyd resins demonstrated outstanding …