Polymer Science Commons^™

Degradable Staples And Delivery Device, Meha Elango, Jessica Cabrera, Makayla Scarpitti, Kareemat Melaiye

Williams Honors College, Honors Research Projects

The scope of this project is to design a method to secure skin grafts to healthy tissue. The ultimate goal for the proposed method is to be dissolvable in some form. Currently, skin grafts procedures utilize staples in most cases to hold a skin graft in place, but there are disadvantages that come with it. Staples are easy to place, but time consuming during the removal procedure. They also cause a lot of pain and discomfort for the patient. The goal of this project is to determine a way a secure skin grafts to healthy skin in order to reduce …

Construction Composites Of Recycled Pvc And Recycled Polyolefins, Natalie Prusovic

Williams Honors College, Honors Research Projects

Current construction composites are typically only composed of polyvinyl chloride (PVC) and recycled PVC (rPVC). This proposed project will investigate if recycled polyethylene (rPE) and polypropylene (rPP) can be used instead of PVC in those materials. Different compositions of rPE, rPP, and rPVC blends will be compounded and a T-peel test will be performed to test the adhesion.

Exploring Natural Raw Materials For The Development Of Hot Melt Adhesives For Linings Of Paintings, Erica Factor

Williams Honors College, Honors Research Projects

Natural raw materials will be explored for developing hot melt adhesives for the lining of paintings. The leading raw material is a natural resin called "Damar". This resin is obtained from the tree family Dipterocaupocea in India and Southeast Asia. This material has shown promising results from initial testing. Damar, with the potential for other natural raw materials, will be combined with synthetic ingredients to create sustainable formulations. The formulations will be tested on linen to replicate the application onto paintings. The sustainability, tackiness, texture, and overall performance of each formula will be considered. Once a formulation has been selected, …

Removal Of Residual Stress In 3d Printed Polymers, Christian Jenkins

Williams Honors College, Honors Research Projects

This project aims to investigate the relationship between stress relaxation and the reduction of dimensional shrinkage and warping in 3D printed polymers produced through fused filament fabrication. The hypothesis suggests that residual stress in 3D printed structures results from factors such as temperature differences, molecular-level contributions, and rapid cooling, causing post-printing warpage and damage. To mitigate these issues, the project proposes annealing 3D printed polymers in a hot sandbath to allow stress relaxation without warping. The study will employ a Dynamic Mechanical Analysis (DMA) machine to assess mechanical properties of relaxed and unrelaxed samples, comparing their effectiveness. The project's timeline …

Functionalized Microfiltration Membranes For Aerosol Capture To Chloro-Organic Degradation, Rollie George Mills

Theses and Dissertations--Chemical and Materials Engineering

The environmental remediation of water and air sources is a challenging field, due to widespread contamination, pollutant variety, and efficiency of existing treatment options. Remediation of certain pollutants, such as per- and polyfluorinated chemicals (PFAS), polychlorinated biphenyls (PCBs), volatile organic compounds (VOCs), and viral aerosols, has shown promise via adsorptive, degradative, or filtration-based processes, each with their respective advantages and limitations. Membrane technology is one option that has exhibited considerable pollutant removal from environmental sources via reverse osmosis (RO) filtration, but is limited by low permeabilities and lack of pollutant detoxification. With the support of NIEHS and NSF, the functionalization …

Development Of Glutathione-Responsive Disulfide-Containing Poly(Beta-Amino Esters) With Varied Hydrophilicity And Acrylate Functionality, Anastasiia Aronova

Theses and Dissertations--Chemical and Materials Engineering

Smart biomaterials are becoming promising for therapeutic deliveries due to their ability to respond to changes in the environment. Redox-responsive hydrogels are a promising type of smart polymer that can swell and degrade according to cellular oxidative stress levels. Glutathione, abundant in cells, is crucial in redox-responsive biomaterials, serving as a key reactive molecule. This study explored the degradation kinetics of glutathione-responsive poly(β-amino ester) (PBAE) polymers created through a single-step Michael addition. We examined how disulfide content influences the degradation kinetics of these PBAE networks. Additionally, we investigated how the hydrophilicity and functionality of acrylate affect the degradation of disulfide-containing …

Sustained Release Systems For Endometrial Cancer, Claire E. Rowlands

Theses and Dissertations--Chemical and Materials Engineering

Endometrial cancer (EC) is the sixth most common cancer in women worldwide and is the most common cancer of female reproductive organs. From 2007-2016 there has been a global rise in incidence of EC of 1.3 %. Typically, EC is treated with surgery, but at later stages surgery is less effective requiring chemotherapy and/or radiation therapy. These treatment options are less effective than surgery and there are very few FDA approved chemotherapies for EC. The minuscule number of effective treatment options as well as an increase in incidence shows the need for creating improved treatments for EC. There has been …

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 …

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 …

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 …

Amine-Functionalized Lignin-Based Ionomer Nanocomposites For Redox Flow Batteries, Joshua Wilder

All Theses

As the development of energy storage technologies for renewable energy sources continues to garner attention, vanadium redox flow batteries (VRFBs) have emerged as promising source for grid-scale energy storage. A major component of the VRFB is the ion exchange membrane (IEM), as it serves to physically separate the two liquid electrolytes and also directly impacts the battery’s capacity, efficiency, and cost. The current industry standard IEM, Nafion™, not only accounts for a large portion of the cost of the VRFB but also suffers from poor proton selectivity. Herein, we have synthesized sulfonated poly(ether ether ketone) (SPEEK) composite membranes containing amine …

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 …

Cellulose Materials For Drug Delivery Applications, Reham Mohamed

Mechanical Engineering Theses

Non-healing wounds are a growing global public health concern due to inadequate or ineffective therapeutic products available. Cellulose-based biopolymers are attractive wound dressing materials due to their biocompatibility, biodegradability, non-toxicity, and cost-effectiveness. This study aims to design and fabricate solid dosage formulations using carboxymethyl cellulose (CMC) and ethyl cellulose (EC) to facilitate multi-stage releases of phenytoin (PHT) and tetracycline hydrochloride (TCH) from plain carriers, fibers/films composites, and layer-by-layer fiber composites. Results from in vitro drug release assays demonstrated a time-dependent release up to 8 hours from PHT-loaded EC fibers, while TCH-loaded CMC films exhibited a rapid release within 5 minutes. …

Influence Of Metal-Coordinating Comonomers On The Coordination Structure And Binding In Magnetic Poly(Ionic Liquid)S, Kayla Foley, Lucas Condes, Keisha B. Walters

Chemical Engineering Faculty Publications and Presentations

A poly(ionic liquid) (PIL), poly(acrylamide-co-diallyl dimethylammonium chloride), was systematically complexed with Co²⁺, Fe³⁺, and Co²⁺/Fe³⁺ (mixed) at different molar equivalencies to form a series of magnetic PILs (MPILs). These novel MPILs were utilized to examine molecular structure and binding between the polymer and metal species using comprehensive spectroscopic studies in both dry and liquid states. FTIR, X-ray photoelectron, UV-vis, and Raman spectroscopies showed evidence of metal coordination of both the iron and cobalt chloride species with the acrylamide comonomer. Using AC susceptibility measurements, the MPILs were found to have magnetic properties …

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 …

Solution And Film Self-Assembly Behavior Of A Block Copolymer Composed Of A Poly(Ionic Liquid) And A Stimuli-Responsive Weak Polyelectrolyte, Kayla Foley, Keisha B. Walters

Chemical Engineering Faculty Publications and Presentations

Cu(0)-mediated atom transfer radical polymerization was used to synthesize a poly(ionic liquid), poly[4-vinylbenzyl-3-butylimidazolium bis(trifluoromethylsulfonyl)imide] (PVBBImTf₂N), a stimuli-responsive polyelectrolyte, poly[2-(dimethylamino)ethyl methacrylate] (PDMAEMA), and a novel block copolymer formed from these two polymers. The synthesis of the block copolymer, poly[2-(dimethylamino) ethyl methacrylate]-block-[poly(4-vinylbenzyl-3-butylimidazolium bis(trifluoromethylsulfonyl)imide] (PDMAEMA-b-PVBBImTf₂N), was examined to evaluate the control of “livingness” polymerization, as indicated by molecular weight, characterizations of degree of polymerization, and ¹HNMR spectroscopy. 2D DOSY NMR measurements revealed the successful formation of block copolymer and the connection between the two polymer blocks. PDMAEMA-b-PVBBImTf₂N was further characterized …

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

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 …

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 …

The Cosolvent And Association Effect On Polymer Behaviors, Xiangyu Zhang

Theses and Dissertations

The blending or mixing is extensively utilized in diverse processes of polymers to bring about advantageous properties, but the behavior becomes intriguing when associations are involved and multi-solvents are used. Explanations based on chemistry-specific arguments are less than satisfactory in abstracting essential features, and lack the general applicability across various systems. So, this work focuses on capturing the physical force governing the phenomenon of interest by using a generic model. Highly non-trivial behaviors of polymers are often observed in multi-solvent solutions. It is known that polymers swell and dissolve in good solvents, while they tend to collapse and aggregate in …