Polymer and Organic Materials Commons^™

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 …

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 …

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 …

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. …

Piezoelectric And Conductive Polymer Based Flexible Devices Enabling Cardiovascular Health Sensing And Energy Harvesting, Andrew Closson

Dartmouth College Ph.D Dissertations

Piezoelectric materials show great promise for low-power wearable and implantable sensing, but their rigidity makes it challenging to integrate them with biological tissue. To address this, researchers have started exploring polymer-based functional materials that offer flexibility and are suitable for interfacing with the human body. However, these materials are still in their early stages, and a framework is necessary to illustrate how these materials, in conjunction with novel fabrication techniques and device designs, can enable the development of multi-functional sensing and energy harvesting devices.

This thesis utilizes highly scalable fabrication methods for functional polymers to build and test a flexible …

Synthesis And Characterization Of Polyaniline-Based High-Performance Carbon For Energy Storage Applications, Udeshika Kangane Arachchige

Electronic Theses & Dissertations

With the increase in global population, the demand for the energy required for daily activities including household necessities, electronic and electric devices, etc. enhances at an alarming proportion. Under these circumstances, supercapacitors (SCs) have attracted great attention as electrochemical energy storage devices. Nowadays, most commercially available supercapacitors are composed of metallic compounds. Due to the high consumption, and limited availability of these elements, it is necessary to find an alternative, effective, low-cost materials in place of using it. With the purpose of achieving high electrochemical performance, this research work focuses on developing carbon derived from polyaniline (PANI) as an efficient …

Development Of Novel Sensor Coating Methodology To Enable Understanding Of Fouling Mechanisms On Ion Exchange Membranes, Andrew Ulmer

Honors Theses

As populations expand and natural water resources are depleted, severe droughts and limited access to clean water have become an increased threat to areas across the world. Effective and economic water treatment methods such as electrodialysis (ED) are vital for combating these threats, especially in developing nations and secluded locations. Organic foulant adsorption on the surface of ion exchange membranes severely limits the capabilities of water desalination systems such as ED along with significantly increasing maintenance costs. Understanding characteristics such as the total amount and rate at which these foulants at specific concentrations adsorb and desorb to the membranes is …

Introduction To Data-Driven Systems For Plastics And Composites Manufacturing, Saeed Farahani, Srikanth Pilla, Yun Zhang, Fausto Tucci

Mechanical Engineering Faculty Publications

Applications of high-performance plastics and composites have widely been expanded to various industries due to their superior properties, such as high strength-to-weight ratio, chemical resistance, and thermal/electrical insulation. However, the numerous possible combinations of polymers and reinforcements/fillers, the variability of these materials, and their complex manufacturing processes pose challenges in terms of efficiently developing new plastics and composites, accurately modeling their properties, and effectively monitoring and controlling their manufacturing processes. Integrating data-driven techniques, such as machine learning, artificial intelligence, and big data analytics, is a promising pathway to overcome these challenges as it is demonstrated by the state-of-the-art research works …

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

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

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 …

Analytical And Experimental Investigation Of Interphase And Dispersion Effects On The Mechanical Stiffness Of Cellulose Nanocomposites, Will Goldberg

McKelvey School of Engineering Graduate Student Theses & Dissertations

The effect of dispersion and interphase properties on the elastic behavior of cellulose nanocomposites was investigated using a number of composite models, experimental data and a thorough literature review. Cellulose nanocomposites consisting of soy protein isolate (SPI) and cellulose nanocrystals (CNC) or polydopamine coated cellulose nanocrystals (PD-CNC) were prepared via solution casting method and tested for mechanical stiffness. These outcomes were compared to standard composite models as well as novel methods adapted from the literature that incorporate data regarding dispersion quality and interphase properties. The literature review verified that both dispersion and interphase properties are highly dependent on interfacial chemistry …

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 …

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.

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 …

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 …

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.

Shape Memory Polymer-Based Multifunctional Syntactic Foams, Siavash Sarrafan

LSU Doctoral Dissertations

With the increase in popularity of shape memory polymers (SMPs), especially in applications such as aerospace, textile, biomedical engineering, and even structures, the weight of the material and the devices made with it has always been a crucial factor. Using the shape memory polymer as a matrix to make a syntactic foam is one of the best and most affordable approaches to creating a lighter material that still has the shape memory effect. The addition of particles of different stiffness, strength, and size, with variable fractions, creates a composite that enables engineering the mechanical, as well as other physical and …

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 …

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 …