Physical Sciences and Mathematics Commons^™

Structure-Property Relationships Of Polyisobutylene-Block-Polyamide Thermoplastic Elastomers, Morgan Dunn Heskett

Master's Theses

Thermoplastic elastomers (TPEs) are a class of polymer fit for a wide variety of applications due to their customizability. In the synthesis of these types of materials, an elastically-performing polymer, deemed the “soft block,” is combined with a stiffer “hard block” polymer, each of which can be selected based on their own specific properties in order to achieve desired material behavior in the final copolymer. Recently, the use of polyisobutylene as a soft block in combination with a polyamide hard block has been investigated for use in TPE synthesis. While the material showed some promising behavior, many properties were still …

Design And Synthesis Of Dynamic Covalent Polymer Scaffolds With Controlled Architectures, Emily Annette Hoff

Dissertations

The design and synthesis of functional, controlled polymer architectures is essential to the development of new materials with precise and tailorable properties or applications. The work described in this dissertation focuses on the development of controlled polymer architectures with dynamic linkages for the design of multifunctional materials and surfaces via robust, efficient, and stimuli-responsive strategies.

In Chapter III, a post-polymerization modification strategy based on ambient temperature nucleophilic chemical deblocking of polymer scaffolds bearing N-heterocycle blocked isocyanate moieties is reported. Room temperature RAFT polymerization of three azole-N-carboxamide methacrylates, including 3,5-dimethyl pyrazole, imidazole, and 1,2,4-triazole derivatives, afforded reactive polymer scaffolds …

Correlation Of Polymer Performance And Hansen Solubility Parameters, Daniel Jobse Mania

Master's Theses

Ready-to-use (RTU) grout is becoming more important to the finish and remodeling construction industry. Market research shows it is a fast-growing product that not only is creating its own space, but is beginning to supplant existing technology.

The original intent of this research was to investigate formulation parameters and how they affect grout performance. It was learned that particle size and oil absorption (OA) value are important filler properties that affect performance as much as adequate packing density and optimal pigment volume concentration (PVC) without going beyond critical PVC (CPVC).

Polymer architecture was also determined to be extremely important, but …

Using Intrinsic Properties Of Polyaniline To Sense Expression Of The Microrna Let-7, Jared N. Gloria

Honors Theses

MicroRNAs are approximately 22-nucleotide long RNA molecules that function through decay and translational repression of messenger RNA. The microRNA let-7 is found to play a role in maintaining the fate of differentiated cells in humans. Thus, expression level of this microRNA is a reliable biomarker of tumor cell phenotype. However, there are significant limitations in the current profiling techniques of microRNA. The current methods like northern blotting, microarrays, RT-PCR, or using locked nucleic acid (LNA) for in-situ hybridization are either laborious, semi-quantitative, or expensive. In this research we try to address this issue by developing a fast, specific, and inexpensive …

The Effect Of Acrylic Acid On Ring Formation In Polyacrylonitrile, Elisha Cade Willis

Honors Theses

The addition of comonomers into carbon fiber precursor, polyacrylonitrile (PAN), has shown to have effects on the extent of stabilization and thermal behavior.1 Acrylic Acid (AA) was added at varying initial apparent weight percent and added via semibatch reaction to copolymerize with acrylonitrile to form carbon fiber precursor. Accompanying batch reactions were synthesized for comparison. Degradation was found to be greater in the semibatch reactions although overall was comparable to the batch reactions. Differential scanning calorimetry (DSC) confirmed the addition of higher concentrations of AA into the reaction resulted in a less intense exotherm upon cyclization, along with a greater …

Synthesis Of Acceptors For Use In Donor-Acceptor Copolymers And Characterization Of These Polymers, William D. Walker

Honors Theses

In this thesis, a selenium-derivatized acceptor was synthesized to examine the heavy atom effects of selenium on the position of the frontier molecular orbitals (HOMO/LUMO band gap) as opposed to sulfur in a donor-acceptor copolymer for use in light harvesting and detection applications. Over the course of this research, standard operating protocols for ultraviolet-visible (UV-Vis-NIR) and Fourier transform infrared (FT-IR) spectroscopies, as well as cyclic voltammetry (CV) characterization techniques were established. Once synthesized, the polymers were characterized through use of the established characterization protocols. The selenium-derivatized polymer exhibited a bathochromic shift compared to the sulfur analogue, with a solid-state absorption …

Functionalizing Β-Cyano Oligo(P-Phenylene Vinylene) Chromophores For Use In Mechanochromic Materials, Alexander J. Wink

Honors Theses

Mechanochromic materials are materials that change color upon mechanical deformation. This concept can be applied in areas of quality control, since the knowledge of damaged parts will easily be detected due to a color change in the material that has undergone deformation. Typically these types of materials are enabled by employing functional small molecules. Often, these are conjugated organic molecules or chromophores, which fluoresce different colors determined by the stimulus (or lack thereof) acting upon the material. In this work, we explore a new avenue to elicit color changes in polymeric materials based on the process of restriction of intramolecular …

Surface And Interfacial Design And Control Of High Performing Thermoplastics: Polysulfones And Beyond, Katrina Marie Knauer

Dissertations

The study of a class of materials almost always begins with the development of an understanding of properties in the bulk state. However, it is the study of surface critical phenomena that has led to a number of new important insights into polymer behavior. A systematic understanding of physical properties in the immediate vicinity of surface and interfacial layers, which cannot be deduced by simple extrapolation of bulk properties, is of significant importance for advancements in polymer applications where the interface drives performance, such as in membranes, coatings, drug-delivery systems, medical devices, and composites.

First, the surface and interfacial modification …

Energy Management Mechanisms Employed At The Human-Material Interface Of Traditional And Minimalist Shod Running, Nadine M. Lippa

Dissertations

From recreational to elite athletes, greater than 50% of runners sustain overuse injuries each year, prompting substantial research efforts to identify causes of—and solutions to—the high injury rate. Different shoe types and material property degradation have been related to injury. Two popular footwear types are traditional shoes with thick graded soles and minimalist running footwear with thinner foam and/or non-graded soles. Notwithstanding 45 years of significant modifications to shoe design features, gained knowledge in kinesiology, and advanced technologies in polymer science, runner injury rates have not decreased and EVA foam has remained the primary running shoe midsole material since the …

Curing Of Polymer Thermosets Via Click Reactions, Mark Richard Brei

Dissertations

In the first project, an azide functional resin and tetra propargyl aromatic diamines were fabricated for use as a composite matrix. These systems take already established epoxy/amine matrices and functionalize them with click moieties. This allows lower temperatures to be used in the production of a thermoset part. These new systems yield many better mechanical properties than their epoxy/amine derivatives, but their T_gs are low in comparison.

The second project investigates the characterization of a linear system based off of the above azide functional resin and a difunctional alkyne. Through selectively choosing catalyst the linear system can show …

Addressing The Issues Of Drug Delivery Via Advanced Macromolecular Design, Brooks Allen Abel

Dissertations

The work described in this dissertation focuses on the development of synthetic approaches toward novel polymer architectures that specifically address the issues of in vivo drug delivery. Successful implementation of the synthetic methodologies described herein required fundamental investigations into the underlying chemistries in ways that now provide greater insights into the nature of the these chemical reactions.

In Section I, the synthesis of tunable pH- and CO₂-responsive sulfonamide-containing polymers using reversible addition-fragmentation chain transfer (RAFT) polymerization is described. Initially, poor polymerization control of methacryloyl sulfonamide (MSA) monomers was observed using traditional RAFT polymerization conditions. Ultimately, reducing the polymerization …