Polymer and Organic Materials Commons^™

Numerical Modeling And Simulation On Deformation And Failure Behaviors Of Polymeric Materials, Heng Feng

Electronic Thesis and Dissertation Repository

Featured by biocompatibility, high compliance and capacity in sustaining large deformation, dielectric elastomers (DEs) and hydrogels have gained extensive research popularity for their potential applications in the fields of soft robots, biomimetics, tissue engineering, drug delivery, and energy harvesting. The design of such soft and smart material-based devices and structures requires deep understanding and accurate simulation of their constitutive behaviors, which is challenged by their nonlinear material properties due to unique microstructures and multi-physics coupling. Meanwhile, in different application contexts, those structures are also susceptible to different failure modes, imposing further challenges in simulating and predicting their performance. To fulfill …

Measurement Of Thermal Conductivity Of Epoxy Resin Reinforced With Different Weight Ratios Of Glass And Carbon Powders, Edrees Edaan Ghadeer

Al-Bahir Journal for Engineering and Pure Sciences

The effect of thermal conductivity was studied on the composites prepared before and after reinforcement with different weight fractions (10, 20, 30, 40, 50, 60 wt %), using a Disc Lee's device, and the dispersion of the filler was studied by morphological analysis of the complexes using scanning electron microscopy (SEM). The (SEM) of glass composite powders, showed a smooth surface with a chance of forming very few voids, clusters and blisters on the surface of the sample, which increased with the increase of the weight fractions of the filled powder. While the composites filled with carbon powders show smooth …

Interlaminar Tensile Properties Of Unidirectional And Woven Carbon Fiber Reinforced Toughened Epoxy Laminates, Eric Timothy Casey, Sean Mckalip Thompson

Materials Engineering

This project aims to develop a dataset on interlaminar tensile strength comparing unidirectional and woven thermoset matrix carbon fiber composites keeping ply count, matrix material, and fiber diameter constant. The interlaminar tensile strength is an important property relating to the delamination failure mode. Interlaminar tensile strength is determined using the ASTM D6415 testing standard. This test is a modified four-point bend test using a 90° curved beam test specimen. Laminates were produced by laying up pre-impregnated carbon fiber sheets onto a curved beam tooling. The unidirectional laminate was produced with 20 plies in a [0,0,90,0,0]₄ layup pattern. The woven …

Surface Characterization Of Low-Density Polyethylene Mulch, Risha Shah

Materials Engineering

Plastic pollution in aquatic systems has traditionally been highlighted in past and current research due to the increase in plastic production every year. Unfortunately, quantitative and qualitative data regarding plastic pollution on land systems such as agricultural mulch is limited. Agricultural mulch breaks down into macroplastics and then degrades into microplastics. The microplastics investigated in this study are all secondary microplastics: microplastics that form due to weathering of larger fragments of plastic. Weathering can occur due to a variety of factors; however, UV radiation and mechanical weathering have been the factors of focus on most current research in microplastic formulation. …

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 …

Effect Of Environmental And Ultraviolet Degradation On The Albedo Of Polyethylene Sheet Materials For Improved Energy Harvesting By Bifacial Photovoltaic Power Plants, William A. Jang, Roxy H. Jackson-Gain

Materials Engineering

Solar energy farms typically utilize monofacial photovoltaic (mPV) cells in their arrays to capture direct sunlight to produce renewable energy. However, the efficiency of these farms can be increased by 2 – 6% through the implementation of bifacial photovoltaic cells (bPV). These bPV cells function by capturing incident ultraviolet (UV) light energy that is reflected off the surface to increase its overall energy production. The amount of UV energy that is reflected is dependent on the albedo value of surface, which is a measure of energy reflectance. In this study, samples of unreinforced polyethylene (PE), scrim-reinforced polyethylene (SR-PE), and woven …

Utilization Of Cellulose Symbiotic Culture Of Bacteria And Yeast (Scoby) With Sweet Tea Media As Methylene Blue And Brilliant Green Biosorbent Material, Leonard Mateus Sigiro, Ahmad Maksum, Donanta Dhaneswara

Journal of Materials Exploration and Findings (JMEF)

The cellulose from Symbiotic Culture of Bacteria and Yeast (SCOBY) can be used as a biosorbent for dye adsorption, such as Methylene Blue and Brilliant Green. This study used sweet tea with a 6% of sugar concentration and 14 days of fermentation time to synthesize biosorbent material from SCOBY. The results from this synthesis are then characterized using FTIR, SEM, and BET. From the result of characterization, it was found that SCOBY has pores formed from cellulose. The results of the average pore size are 1.5976nm with a pore volume of 0.229cc/g, while the specific surface area is 143.244m2/g. 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 …

Comparative Analysis On Low Cost Continuous Carbon Fiber Polypropylene Composite Using Compression Molding And Automated Tape Placement, Benjamin U. Schwartz

Masters Theses

Carbon fiber reinforced plastics (CFRP) are widely used throughout the aerospace industry where a weight reduction remains the highest priority with less emphasis on cost. Textile grade carbon fiber (TCF) and other low cost carbon fiber (LCCF) alternatives have recently emerged for use in the automotive market where emissions regulations have pushed automotive manufacturers and research institutions to look for cost effective light weight materials. Fiber reinforced thermoplastics provide an effective solution that align with automotive design including low cost, high processing rates, high impact toughness, unlimited shelf life, and recyclability.

TCF and Zoltek_PX35 fibers are two LCCF aimed at …

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 …

Mesoscale Modeling Of Controlled Degradation In Polymer Networks And Melts, Vaibhav Palkar

All Dissertations

Controlled degradation of polymers finds various applications in fields ranging from the design of functional soft materials to recycling of polymers. In several of these applications, the characteristic length scale at which relevant processes occur ranges from nanometers to microns, typically referred to as the mesoscale. Although analytical models and continuum approaches inform our current understanding, analysis of degradation at the mesoscale is exceptionally limited. For modeling degradation at the mesoscale, we use the Dissipative Particle Dynamics (DPD) technique and the LAMMPS simulation software. Within the DPD framework, we model controlled degradation or the breaking of covalent bonds within a …

Formulation And Optimization Of Algae-Filled Polylactic Acid Thermoplastic Compounds For Improved Biodegradation, Sydney A. Cole

Honors Theses

Conventional plastics derived from non-renewable petrochemicals – especially from fossil reserves – have become an integral part of human life because their structure can be chemically manipulated to obtain a wide range of properties and geometries necessary in nearly all industries. The volume and rate at which petroleum plastics are produced, used, and discarded has incited several significant issues related to human health, environmental conservation, and ecological biodiversity. To address these issues, many institutions have begun investigating solutions in both the development and end-oflife phases of plastic production and waste. In this thesis, a Chlorella-dominated algae mixture is dried and …

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 …

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.

Optical Fiber Tip Micro Anemometer [U.S. Patent Us11635315b2], Hengky Chandrahalim, Jeremiah C. Williams

Faculty Publications

A passive microscopic flow sensor includes a three-dimensional microscopic optical structure formed on a cleaved tip of an optical fiber. The three-dimensional microscopic optical structure includes a post attached off-center to and extending longitudinally from the cleaved tip of the optical fiber. A rotor of the three-dimensional microscopic optical structure is received for rotation on the post. The rotor has more than one blade. Each blade has a reflective undersurface that reflects a light signal back through the optical fiber when center aligned with the optical fiber, the blades of the rotor shaped to rotate at a rate related to …

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 …

Vapor Deposition Of Self-Wrinkling Polymer Films, Robert N. Enright

Doctoral Dissertations

Initiated chemical vapor deposition is used to grow polymer films on substrates of various three-dimensional shapes which exhibit wrinkling during film growth, termed self-wrinkling. Self-wrinkling avoids separate film growth and compression steps and more-closely mimics processes observed in nature. The self-wrinkling process is elucidated on flat elastic substrates, revealing control over the amount of compressive stress by changing deposition conditions. Next, a study of films grown on liquid substrates with interface profiles that either resemble cylinders or contain repeating concave cones, saddles, and bowls affirms the principle that the wrinkle roundness increases with interface curvature. The selection of high versus …

Additive Manufacturing For Phase Change Thermal Energy Storage And Management, Thomas B. Freeman

Doctoral Dissertations and Master's Theses

Phase change materials can enhance the performance of energy systems by time shifting or reducing peak thermal loads. Certain electronic devices such as batteries, laser systems, or electric vehicle power electronics are highly transient and require pulse heat dissipation. Heat sinks, or thermal management devices made of a phase change material can absorb large heat spikes while maintaining a constant temperature. Additive manufacturing techniques hold tremendous potential to enable co-optimization of material properties and device geometry, while potentially reducing material waste and manufacturing time. Recently, a few efforts have emerged that employ additive manufacturing techniques to integrate a phase change …