Polymer Science Commons^™

Synthesis Of Double Network Hydrogels Which Can Be Shaped Freely, Natsuki Morimoto, Norie Kato

The International Student Science Fair 2018

Double network (DN) hydrogels have specific characters such as flexibility and high mechanical strength. They are expected to use biomaterials such as artificial cartilages and meniscuses. The purpose of this study is to synthesize DN gels which can be shaped freely. DN gels were synthesized by polyvinyl alcohol (PVA) as a mold, 2-acrylamide-2-methylpropane sulfonic acid (AMPS) as a first monomer, N,N’-methylene-bis-acrylamide (MBAA) as a crosslinker, 2-oxoglutalic acid (OGA) as an initiator and acrylamide (AAm) as a second monomer. First, PVA (polymerization degree; 2000) was dissolved in the water and prepared to 15 % of aqueous solution. It was poured ...

An Entirely New Molecular Glue For Mof Using Unusual Structural Transformation Of A Coordination Polymer, Sukwoo Jung, Hangyeol Kim, Junseok Ahn

The International Student Science Fair 2018

In this research, an entirely new molecular glue is reported. This ‘coordination polymer glue’ is synthesized from zinc metal and BDC-NPE(2,5-bis{4-[1-(4-nitrophenyl)ethylamino]butoxy}terephthalic acid). Molecular glue transforms from 1D coordination polymer to a 3D cross-linked framework, resulting in a phase change of solution to solid. The carboxylate group of this glue makes the preformed MOF bind to its framework. Therefore, when the solution of molecular glue is mixed with preformed MOF powder and heated, homogeneous and thin MOF film – MOF/ZnNPE film – is fabricated. The film is irrelevant to the kind of its substrate ...

Chemically Modified Gellan Gum Hydrogels With Tunable Properties For Use As Tissue Engineering Scaffolds, Zihao Xu, Zhuqing Li, Shan Jiang, Kaitlin M. Bratlie

Chemical and Biological Engineering Publications

Gellan gum is a naturally occurring polymer that can cross-link in the presence of divalent cations to form biocompatible hydrogels. However, physically cross-linked gellan gum hydrogels lose their stability under physiological conditions, thus restricting the applications of these hydrogels in vivo. To improve the mechanical strength of the gels, we incorporated methacrylate into the gellan gum and chemically cross-linked the hydrogel through three polymerization methods: step growth through thiol–ene photoclick chemistry, chain-growth via photopolymerization, and mixed model in which both mechanisms were employed. Methacrylation was confirmed and quantified by proton nuclear magnetic resonance (1H NMR) and Fourier transform infrared ...

An Entirely New Molecular Glue For Mof Using Unusual Structural Transformation Of A Coordination Polymer, Sukwoo Jung, Hangyeol Kim, Junseok Ahn

The International Student Science Fair 2018

In this research, an entirely new molecular glue is reported. This ‘coordination polymer glue’ is synthesized from zinc metal and BDC-NPE(2,5-bis{4-[1-(4-nitrophenyl)ethylamino]butoxy}terephthalic acid). Molecular glue transforms from 1D coordination polymer to a 3D cross-linked framework, resulting in a phase change of solution to solid. The carboxylate group of this glue makes the preformed MOF bind to its framework. Therefore, when the solution of molecular glue is mixed with preformed MOF powder and heated, homogeneous and thin MOF film – MOF/ZnNPE film – is fabricated. The film is irrelevant to the kind of its substrate ...

Polymer Nanocomposites Containing High Aspect Ratio Particulates: Innovation In Co-Extruded Multilayer Barrier Films, Kevin Meyers

Dissertations

Delaminated montmorillonite (MMT) clay/ maleic anhydride grafted LLDPE nanocomposite multilayer films with alternating layers of LDPE were produced through multilayer co-extrusion. The MMT concentration within the nanocomposite layers was increased through annealing the films in the melt due to a mismatch in interdiffusion rates of the polymer layers. Analysis of the nanocomposite layers upon annealing revealed that the platelets impinged upon one another resulting in significant improvement in oxygen barrier in the multilayer system, exceeding the results of bulk nanocomposites.

Model analysis demonstrated that increasing the nanoplatelet aspect ratio or initial concentration in the filled layers would lead to even ...

A Proposed Process And Economic Analysis For A Manufacturing Facility For Nylon 6,6, Perry Doles

Chemical Engineering Undergraduate Honors Theses

The global nylon market is a multi-billion-dollar industry that has been thriving in recent years due to advances in the process technology and its flexibility as a material. Nylon 6,6 is a versatile material with uses in many industries because of its ability manipulated into many forms. It is commonly used in applications that require heat resistance, chemical resistance, and high mechanical strength. It is commonly used in luggage, car parts, carpets, and many other plastic products that require the properties that nylon 6,6 exhibits. The versatility and demand for nylon 6,6 make it an attractive process ...

Review Of Challenges And Advances In Modification Of Food Package Headspace Gases, Ziynet Boz, Bruce A. Welt, Jeffrey K. Brecht, William Pelletier, Eric Mclamore, Gregory A. Kiker, Jason E. Butler

Journal of Applied Packaging Research

Modified Atmosphere Packaging (MAP) has been widely used as an effective way to preserve foods. Fresh produce, meat and meat products, seafood, and dairy products can benefit from modified gaseous atmospheres, which are usually achieved by reducing oxygen and increasing carbon dioxide concentrations, within limits, defined by product tolerances. MAP of fresh produce is particularly challenging because products are living and respiring. Respiration rates depend on several factors including temperature, oxygen, and carbon dioxide concentrations. Balancing package permeation with respiration is challenging, often due to limited selection of practical packaging materials. Failing to remain within tolerance limits of products leads ...

Waste Management By Waste: Removal Of Acid Dyes From Wastewaters Of Textile Coloration Using Fish Scales, S M Fijul Kabir

LSU Master's Theses

Removal of hazardous acid dyes by economical process using low-cost bio-sorbents from wool industry wastewaters is of a pressing need, since it causes skin and respiratory diseases and disrupts other environmental components. Fish scales (FS), a by-product of fish industry, a type of solid waste, are usually discarded carelessly resulting in pungent odor and environmental burden. In this research, the FS of black drum (Pogonias cromis) were used for the removal of acid dyes (acid red 1 (AR1), acid blue 45 (AB45) and acid yellow 127 (AY126)) from wool industry wastewaters by absorption process with a view to valorizing fish ...

Recent Approaches In Designing Bioadhesive Materials Inspired By Mussel Adhesive Protein, Pegah Kord Forooshani, Bruce P. Lee

Bruce Lee

Marine mussels secret protein-based adhesives, which enable them to anchor to various surfaces in a saline, intertidal zone. Mussel foot proteins (Mfps) contain a large abundance of a unique, catecholic amino acid, Dopa, in their protein sequences. Catechol offers robust and durable adhe-sion to various substrate surfaces and contributes to the curing of the adhesive plaques. In this article, we review the unique features and the key functionalities of Mfps, catechol chemistry, and strategies for preparing catechol-functionalized poly- mers. Specifically, we reviewed recent findings on the contributions of various features of Mfps on interfacial binding, which include coacervate formation, surface ...

Definite Indefiniteness Of "Molecular Weight" As A Claim Term For Polymer-Related Patents, Ping-Hsun Chen

The Journal of Business, Entrepreneurship & the Law

The molecular weight of a polymer is not just a number for a single molecule. In fact, molecular weight measurement is based on a large volume of molecules of the same polymer. Due to the non-uniformity of molecular weights, there are several methods to measure an “average molecular weight” of a polymer. Unfortunately, the Federal Circuit in Teva Pharms. USA, Inc. v. Sandoz, Inc., 789 F.3d 1335 (Fed. Cir. 2015), held that the term “molecular weight” in several polymer claims was indefinite, because the term could mean either peak average molecular weight, number average molecular weight, or weight average ...

Surface Engineering And Monomer Design For Light-Mediated Ring Opening Metathesis Polymerization, Ishan A. Fursule

Theses and Dissertations--Chemical and Materials Engineering

Stimuli-responsive materials are changing the landscape of actuated materials, optoelectronics, molecular machines, solar cells, temporary memory storage, and biomedical materials. Specifically, photo-responsive polymers have gained acceleration in research and application since the last two decades in the form of a surface coating and micro-patterns. Light as a stimulus can be coherent, mono or polychromatic, tunable for power (intensity) and energy (wavelength), and has precise spatiotemporal control. Conventional surface coating techniques such as spin coating are unable to impart properties to the coatings in terms of sturdiness, homogeneity, uniformity over the complex surface, post deposition modification, and process efficiency. Also, in ...

Effects Of Hofmeister Ions On Gelation Of Gelatin And Pluronic Hydrogels, Eric Britton

Honors Research Projects

The purpose of the project was to observe the effects of the Hofmeister series of ions on the gelation of gelatin and Pluronic-127 hydrogels. Hydrogels are semi-solid materials that contain a network of joined molecules through intermolecular interactions which are capable of holding water. Gelatin and Pluronic-127 (PF-127) are thermoreversible, physical crosslinked gels. Gelation occurs when temperature, or other driving forces, reduce the polymer chain solubility until a distinct 2-phase system forms. When aqueous ions are present in solution, they exhibit specific ion effects that have either a stabilizing or destabilizing effect on the solubility of proteins and other polymers ...

Tandem Mass Spectrometry (Ms/Ms) For Determination Of Architecture Of Synthetic Polymers, Shoumik Saha

Honors Research Projects

Tandem Mass Spectrometry (MS/MS) was used to determine the architecture of synthetic polymers and they are difluorene-N₃, 3-difluorene-N₃ and VPOSS-3-difluorene. VPOSS materials usually exhibit electrochemical properties and the research was performed to determine their accurate structure and to provide evidence of their proper synthesis. The compounds were mixed with a matrix solution, DCTB, and a silver salt to enable proper protonation. The solvent mixture was on a MALDI plate and then put into the mass spectrometer. The mass spectrum generated was analyzed and each fragment was identified to structures with the synthetic polymers via ChemDraw. Thus, trial ...

Electrospinning Aqueous Solutions Of Poly(Ethylene Oxide) Using A Corona-Type Apparatus, Nicholas Neill

Honors Research Projects

The purpose of this project was to evaluate working parameters for the corona spinneret to create electrospun fibers/ fiber mat. This project was set-up using a Box-Behnken design of experiment. The working parameters were investigated by performing the electrospinning process, altering the working conditions, collecting the electrospun fibers. The scope of this project includes three primary operational conditions: distance between the spinneret and the collection plate, the viscosity (weight percent) of PEO in the spinning solution and the weight percent of NaCl in the spinning solution. The distance between the spinneret and the collection plate were varied to 18 cm ...

Correlation Of Electrospun Polyvinylpyrrolidone Fiber Mat Thickness With Basis Weight, Fiber Diameter, Pore Size Distribution, And Air Permeability, Leah Mcpherson

Honors Research Projects

This project developed correlations between electrospun polyvinylpyrrolidone fiber mat thickness, basis weight, fiber diameter, pore size, and air permeability. The hypotheses were thinner fibers produce thicker mats, pore size decreases with fiber diameter, pore size and permeability decrease as basis weight increases. Project results could be used for modeling or quality control purposes.

Fiber diameter distributions were analyzed using a Scanning Electron Microscope and FibraQuant 1.3 software. Four conditions were chosen for further study: 0.284 ± 0.104 µm, 0.379 ± 0.128 µm, 0.520 ± 0.138 µm, and 0.733 ± 0.177 µm. Lower PVP concentrations produced ...

Modeling The Effect Thickener Structure Has On The Oil Release Of Grease, Dana Cressman

Honors Research Projects

Our hypothesis was that the thickener type and micelle concentration of grease affected its viscoelastic properties. Measurements were made using a TA AR G2 rheometer and calculations were made using TA rheometer analysis software to characterize the viscoelastic response of grease under oscillatory shear and frequency tests. The oscillatory frequency tests determined the critical micelle concentration. The oscillatory stress tests were taken at temperatures from 5 to 65 degrees Celsius to create a master curve based on time temperature superposition of the measurements. The crossover points of G’ and G” on the oscillatory stress tests demonstrated where the grease transitions ...

The Role Of Microenvironment Reagent Solubility On Reaction Kinetics Of 4-Nitrophenol Reduction, Michael P. Zeevi, Andrew Harrison, Christina Tang

Undergraduate Research Posters

The Role of Microenvironment Reagent Solubility on Reaction Kinetics of 4-Nitrophenol Reduction

Michael Zeevi¹ with Andrew Harrison¹ and Christina Tang, PhD¹

¹Department of Chemical and Life Science Engineering, VCU School of Engineering

Introduction: Nanoparticles are of increasing interest due to their high surface area to volume ratio, as well as that they enable fine-tuning of the reaction microenvironment. Through flash nanoprecipitation, core-shell polymer nanoreactors were formed by directed self-assembly. Using the reduction of 4-nitrophenol as a model reduction reaction, we investigated the effect of reagent solubility in the nanoreactor microenvironment’s on nanoreactor kinetics.

Methods: The ...

Connecting The Dots: A New Method To Determine Radiation Yield During Electron Beam (Eb) Polymerization Reactions Via Raman Spectroscopy, Renae Kurpius

University of Iowa Honors Theses

Electron-beam (EB) polymerization is a fast, solvent-free, low-energy means of polymerizing inks, thin films, and coatings such as those used in food packaging. During EB polymerization, accelerated electrons interact with liquid monomer molecules to form radicals, which continue to react with other monomer molecules and form long chain, solid polymers. The final polymer properties are dependent on the monomer chemistry, as well as processing conditions such as dose (i.e., the amount of energy absorbed by the sample), belt speed (i.e., the rate at which the sample travels through the electron-beam unit), and dose rate (i.e., the rate ...

Responsive Pentablock Copolymers For Sirna Delivery, Surya K. Mallapragada, Metin Uz, Sacide Alsoy Altinkaya

Surya K. Mallapragada

In this study, temperature and pH responsive cationic and amphiphilic pentablock copolymers, which consist of the temperature responsive triblock Pluronic F127 sandwiched between pH responsive PDEAEM (poly(2-diethylaminoethyl methacrylate)) end blocks, were used for the first time in the development of polyplex and gold nanoparticle (AuNP) based multicomponent siRNA delivery systems (MCSs). Copolymers in both systems protected siRNA from external effects, provided cell entry and endosomal escape. The thermoreversible micellization of the hydrophobic PPO block facilitated the cellular entry while the PDEAEM blocks enhanced the endosomal escape through protonated tertiary amine groups by pH buffering. The synergistic advantages of the ...

Spray-Dried Cellulose Nanofibril-Reinforced Polypropylene Composites For Extrusion-Based Additive Manufacturing, Lu Wang

Electronic Theses and Dissertations

Compared to conventional manufacturing process, additive manufacturing (AM) offers free-form design, lighter and more ergonomic products, short lead time and less waste. Extrusion-based AM can be used to print thermoplastics. However, extrusion-based AM has processing challenges in printing semi-crystalline thermoplastics, for instance, polypropylene (PP). Cellulose nanofibrils (CNF) are one type of cellulose nanofibers that are produced from pulp fibers. CNF has extraordinary properties which make it an ideal candidate to reinforce polymers. Spray-dried CNF (SDCNF) is able to be incorporated into thermoplastic matrices without modifying conventional processing procedures.

The mechanical properties of 3D printed plastic parts have been considered significantly ...