Polymer Chemistry Commons^™

High-Temperature Resistant Water-Soluble Polymers Derived From Exotic Amino Acids, Sumant Dwivedi, Aniruddha Nag, Shigeki Sakamoto, Yasuyoshi Funahashi, Toyohiro Harimoto, Kenji Takada, Tatsuo Kaneko

Faculty Publications

© The Royal Society of Chemistry. High-performance water-soluble polymers have a wide range of applications from engineering materials to biomedical plastics. However, existing materials are either natural polymers that lack high thermostability or rigid synthetic polymers. Therefore, we design an amino acid-derived building block, 4,4′-diamino-α-truxillate dianion (4ATA²⁻), that induces water solubility in high-performance polymers. Polyimides containing 4ATA²⁻ units are intrinsically water-soluble and are processed into films cast from an aqueous solution. The resulting polyimide films exhibit exceptional transparency and extremely high thermal stability. In addition, the films can be made insoluble in water by simple post-treatment using …

Effect Of Different Phosphate Glass Compositions On The Process-Induced Macromolecular Dynamic Of Polyamide 66, Imane Belyami, Mohammad K. Hassan

Faculty Publications

The present study provides a fundamental understanding of the mechanism of action of special new phosphate glass (P-glass) systems, having different glass transition temperatures (T_g), in polyamide 66 (PA66). Dynamic mechanical analysis (DMA) revealed that the T_g of PA66/low T_g P-glass (ILT-1) was significantly shifted to a lower T_g (65 °C), and another transition appeared at high temperature (166 °C). This was supported by a drop in the melting point and the crystallinity of the PA66/ILT-1 hybrid material as detected by differential scanning calorimetry (DSC). The dielectric spectroscopic investigation on the networks’ molecular level structural …

An Atomistic Study Of The Effects On Mechanical Properties And Bonding Interactions Of Carbon Nanofillers In Nylon 6 Nanocomposites, Michael Roth

Dissertations

Polymers have potential for a wide range of applications. The effectiveness of polymers can be further enhanced through the addition of nanofillers that improve thermal, mechanical, and electrical properties of the polymer. Carbon based nanofillers such as carbon nanotube (CNT), graphene, and carbon nanofibre (CNF) are of particular interest due to their high properties and high aspect ratios. However, limited understanding of the governing interactions of these nanofillers with polymers limits the effectiveness of the final nanocomposite.

The first facet of this dissertation focuses on determining the dominating interactions between pristine CNT and graphene with nylon 6 monomer and the …

Effect Of Selfsame Microparticles On Epoxide Amine Network Formation And Matrix Mechanics, Travis Palmer

Dissertations

Epoxide amine matrices are widely utilized in aerospace carbon fiber reinforced polymer (CFRP) composites having engendered significant reductions in weight and fuel consumption. This dissertation focuses on the effect of constrained space during network formation on the matrix mechanics of these highly complex composite systems. Precipitation polymerization conditions are developed to prepare epoxide amine microparticles (EMs) based on tetraglycidyl-4,4’-methylenedianiline (TGDDM) and isophorone diamine (IPDA). Surface functionality of EMs is tuned via control of epoxide to reactive amine hydrogen ratio, where unreactive, amine- and epoxide-functional EMs are prepared. We demonstrate that EMs are polydisperse, but can be filtered, yielding low dispersity …

Huisgen 1,3-Dipolar Azide-Alkyne Cycloaddition “Click” Reaction In Polymer Synthesis And Curing, Jie Wu

Dissertations

This dissertation’s key focus is on utilizing Huisgen 1,3-dipolar azide-alkyne cycloaddition (AAC) reaction in copolymer synthesis and modification, including thermoplastic block copolymer and commercially available two-component polyurethane system. It can be divided into two major projects, introduced as follows.

The first project involves the development of a modular synthetic approach toward polyisobutylene (PIB)-based triphasic pentablock thermoplastic elastomer with enhanced moisture permeability. This terpolymer consists of a poly(styrene-b-isobutylene-b-styrene) (SIBS) core and appended hydrophilic polymer blocks (HBs). The SIBS core was synthesized via living cationic polymerization (LCP) of isobutylene followed by sequential addition of styrene. AAC was utilized …

Thiol-Ene Click Chemistry For Solid State Triplet-Triplet Annihilation Upconversion And Parts-Per-Billion Pyrophosphate Sensing In Artificial Seawater, Abagail K. Williams

Master's Theses

Thiol-ene click chemistry is a robust approach to molecularly engineering polymers for many applications. Within this work, thiol-ene click chemistry is used to fabricate thiol-ene networks for TTA-UC and to synthesize a conjugated polyelectrolyte (CPE) used as a pyrophosphate (PPi) sensor in complex aqueous media. Chapter I focuses on the synthesis and upconversion performance of rubbery networks fabricated using thiol-ene click photopolymerization. The advancement of triplet-triplet annihilation based upconversion (TTA-UC) in emerging technologies necessitates the development of solid-state systems that are readily accessible and broadly applicable. We demonstrate that thiol-ene click chemistry can be used as a facile cure-on-demand synthetic …

Investigation On The Morphology Of Charge-Transfer Complexes In Low Density Polyethylene, Wade Korf

Master's Theses

Fillers are used ubiquitously throughout the fields of polymer and material science to overcome many inherent limitations to polymeric materials (i.e. poor stiffness or strength) and to expand their potential applications. There is a need to develop controllable particle architectures to better understand fundamental structure-property relationships in particle reinforced polymer composites. Charge-transfer complexes (CTCs) can assemble in situ into various needle and dendritic shapes via simple fabrication processes and at low loading levels. In this study, the effect of tetrathiafulvalene (TTF) and 7,7,8,8-tetracyanoquinodimethane (TCNQ) CTC crystallites of various shapes and sizes on composite mechanical properties was investigated in an LDPE …

Discriminating Azo Dyes: Conjugated Polymers, The Inner Filter Effect, And Array Sensors, Erin Crater

Honors Theses

Azo dyes are abundant pollutants that contaminate water supplies and threaten humans, biota, and ecosystem health. Their detection and discrimination are an incredible challenge due to the structural, chemical, and optical similarities between dyes, the complexity of the wastewater environment in which they are found, and their low environmental concentrations. In this work, the inner filter effect (IFE), combined with conjugated polymer array-based sensing, is utilized for the quantitative profiling of these pollutants. The array was constructed using three fluorescent, anionic conjugated polyelectrolytes whose varying spectroscopic properties led to distinct IFE patterns in the presence of the dyes. The unique …

Synthesis, Characterization, Dna Binding, Topoisomerase Inhibition, And Apoptosis Induction Studies Of A Novel Cobalt(Iii) Complex With A Thiosemicarbazone Ligand, Stephen J. Beebe, Michael J. Celestine, Jimmie L. Bullock, Shayna Sandhaus, Jessa Faye Arca, Donald M. Cropek, Tekettay A. Ludvig, Sydney R. Foster, Jasmine S. Clark, Floyd A. Beckford, Criszcele M. Tano, Elizabeth A. Tonsel-White, Raj K. Gurung, Courtney E. Stankavich, Yuk Ching Tse-Dinh, William L. Jarrett, Alvin A. Holder

Faculty Publications

In this study, 9-anthraldehyde-N(4)-methylthiosemicarbazone (MeATSC) 1 and [Co(phen)₂(O₂CO)]Cl·6H₂O 2 (where phen = 1,10-phenanthroline) were synthesized. [Co(phen)₂(O₂CO)]Cl·6H₂O 2 was used to produce anhydrous [Co(phen)₂(H₂O)₂](NO₃)₃ 3. Subsequently, anhydrous [Co(phen)₂(H₂O)₂](NO₃)₃ 3 was reacted with MeATSC 1 to produce [Co(phen)₂(MeATSC)](NO₃)₃·1.5H₂O·C₂H₅OH 4. The ligand, MeATSC 1 and all complexes were characterized by elemental analysis, FT IR, UV–visible, and multinuclear NMR ( …

Adsorption Of Polyisobutylene-Based Dispersants Onto Carbon Black, Travis Paul Holbrook

Dissertations

The formation of carbonaceous by-products (e.g. soot) during the operation of an internal combustion engine is unavoidable and the aggregation of this soot leads to deleterious effects including abrasive wear of the engine, increased oil viscosities, and sludge deposition. Dispersants, which are composed of a hydrophobic tail and a polar headgroup, are used as oil additives to aid in the suspension and stabilization of the soot particles. Polyisobutylene succinimide (PIBSI) is the most well-studied class of dispersants and is characterized by a linear architecture and polyamine headgroup that interacts with soot by acid-base and dipole-dipole interactions. As such, there remains …

The Antimicrobial Activity And Cellular Targets Of Plant Derived Aldehydes And Degradable Pro-Antimicrobial Networks In Pseudomonas Aeruginosa, Yetunde Adewunmi

Dissertations

Essential oils (EOs) are plant-derived products that have been long exploited for their antimicrobial activities in medicine, agriculture, and food preservation. EOs represent a promising alternative to conventional antibiotics due to the broad-range antimicrobial activity, low toxicity to human commensal bacteria, and the capacity to kill microorganisms without promoting resistance. Despite the progress in the understanding of the biological activity of EOs, many aspects of their mode of action remain inconclusive. The overarching aim of this work was to address these gaps by studying molecular interactions between antimicrobial plant aldehydes and the opportunistic human pathogen Pseudomonas aeruginosa. We initiated …

Stretchable Self-Healable Semiconducting Polymer Film For Active-Matrix Strain-Sensing Array, Jin Young Oh, Donghee Son, Toru Katsumata, Yeongjun Lee, Yeongin Kim, Jeffrey Lopez, Hung-Chin Wu, Jiheong Kang, Joonsuk Park, Xiaodan Gu, Jaewan Mun, Nathan Ging-Ji Wang, Yikai Yin, Wei Cai, Youngjun Yun, Jeffrey B.-H. Tok, Zhenan Bao

Faculty Publications

Skin-like sensory devidces shoud be stretchable and self-healable to meet the demands for future electronic skin applications. Despite recent notable advances in skin-inspired electronic materials, it remains challenging to confer these desired functionalities to an active semiconductor. Here, we report a strain-sensitive, stretchable, and autonomously self-healable semiconducting film achieved through blending of a polymer semiconductor and a self-healable elastomer, both of which are dynamically cross-linked by metal coordination. We observed that by controlling the percolation threshold of the polymer semiconductor, the blend film became strain sensitive, with a gauge factor of 5.75 x 10⁵ at 100% strain in a …

Melt Electrospinning Designs For Nanofiber Fabrication For Different Applications, Yasseen S. Ibrahim, Essraa A. Hussein, Moustafa M. Zagho, Ghada G. Abdo, Ahmed A. Elzatahry

Faculty Publications

Nanofibers have been attracting growing attention owing to their outstanding physicochemical and structural properties as well as diverse and intriguing applications. Electrospinning has been known as a simple, flexible, and multipurpose technique for the fabrication of submicro scale fibers. Throughout the last two decades, numerous investigations have focused on the employment of electrospinning techniques to improve the characteristics of fabricated fibers. This review highlights the state of the art of melt electrospinning and clarifies the major categories based on multitemperature control, gas assist, laser melt, coaxial, and needleless designs. In addition, we represent the effect of melt electrospinning process parameters …

Modifying Inhibited Primer Performance Via Control Of Epoxy-Amine Matrix Structure And Composition, Steven Wand

Dissertations

This research represents an effort to deliver a new fundamental understanding of how polymer matrix characteristics influence corrosion protection of organic coatings, in particular the performance of corrosion inhibitor-containing primers. By modifying the structure and composition features of epoxy-amine matrices which commonly serves as the binder for protective coatings, the thermal/mechanical, adhesion, and transport properties which govern coating performance and inhibitor release were altered in such a way that directly influenced protection efficacy. This research is composed of three distinct approaches towards systematically varying thermoset network characteristics and observing the resulting impact on transport behaviors and corrosion prevention, with an …

“Polysoaps” Via Raft Copolymerization To Form Well-Defined Micelles For Water Remediation And Targeted Drug Delivery Applications, Phillip Pickett

Dissertations

Amphiphilic copolymers have become increasingly important for environmental and biological applications due to their behavioral characteristics in aqueous solution. For example, structurally-tailored statistical amphiphilic copolymers or “polysoaps” can self-assemble into micelles or other architectures in water at various concentrations. Polysoaps may be differentiated from small molecule surfactant micelles in their capability to self-assemble into unimolecular associates (unimolecular micelles) with no dependence on concentration. Such micelles offer enormous potential for dispersion of hydrophobic species in water at high dilution. Importantly, each polymer chain forms its own micelle and upon dilution, these micelles remain intact and capable of dispersing hydrocarbon material in …

Engineering Multifunctional And Morphologically Diverse Polymer Brush Surfaces, Cassandra M. Reese

Dissertations

The combination of surface-initiated polymerization (SIP) and post-polymerization (PPM) serves as a powerful approach to fabricate complex, multifunctional polymer films, which can be precisely tuned for desired surface engineering applications. Careful manipulation of PPM parameters such as reaction conditions, the tethered brush parameters, and the physical properties of the unbound post-modifier greatly influence the depth of penetration of the post-modifier and the polymer brush compositional heterogeneity. This dissertation focuses on engineering polymer brush surfaces with multifunctional chemistries and tunable morphologies by investigating the PPM parameters that dictate the distribution of post-modifiers on grafted polymer brush surfaces.

The first chapter of …

Evaluating Corrosion Altering Properties Of Thiophene Based Copolymers, Robert Peterson

Dissertations

There is an important and ongoing debate on how or whether conductive polymers (CP) alter corrosion performance with some researchers reporting that CPs ultimately accelerate corrosion and others saying CPs, if understood could possibly replace the world’s best standard for corrosion prevention, i.e., chromium based inhibitors. The primary project goal was to improve our understanding of how CPs alter corrosion chemistry by 1) controlling the polymer structure and 2) in-turn the properties and then 3) targeting the best protocol for fast corrosion kinetic evaluation.

We detail the copolymer synthesis results and shift in corrosion protection properties for …

Synthesis, Characterization, And Utilization Of Iron Ii Ion Sensing Fluorescent Probes For Detection Of Early Onset Anodic Corrosion, Dane N. Wedgeworth

Honors Theses

Corrosion effects can be seen in infrastructure all around the world. From rusted bridges, ships, and other steel surfaces, the price of corrosion adds up quickly with repairs, maintenance, and complete replacement. Common approaches to corrosion detection and prevention require slow, optical inspection to begin the repair and maintenance process, which can also be very slow and costly. However, recent literature suggests that metal chelating probes can yield new understanding of the processes of corrosion faster and with greater specificity in location and diversity in mechanisms for early onset of corrosion. Earlier corrosion detection can be characterized by several ways. …

A High-Spin Ground-State Donor-Acceptor Conjugated Polymer, Alex E. London, H. Chen, M.A. Sabuj, Joshua Tropp, M. Saghayezhian, Naresh Eedugurala, B.A. Zhang, Y. Liu, Xiaodan Gu, B.M. Wong, N. Rai, M.K. Bowman, Jason D. Azoulay

Faculty Publications

Interest in high-spin organic materials is driven by opportunities to enable far-reaching fundamental science and develop technologies that integrate light element spin, magnetic, and quantum functionalities. Although extensively studied, the intrinsic instability of these materials complicates synthesis and precludes an understanding of how fundamental properties associated with the nature of the chemical bond and electron pairing in organic materials systems manifest in practical applications. Here, we demonstrate a conjugated polymer semiconductor, based on alternating cyclopentadithiophene and thiadiazoloquinoxaline units, that is a ground-state triplet in its neutral form. Electron paramagnetic resonance and magnetic susceptibility measurements are consistent with a high-to-low spin …

Functional Polymers Through Mechanochemistry, Stephen Schrettl, Diedrik W.R. Balkenende, Céline Calvino, Marc Karman, Ana Lavrenova, Laura N. Neumann, Yoshimitsu Sagara, Ester Verde-Sesto, Michela Di Giannantonio, Yoan C. Simon, Katharina M. Fromm, Marco Lattuada, Christoph Weder

Faculty Publications

While coupling mechanical and chemical processes is widespread in living organisms, the idea to harness the mechanically induced dissociation of weak covalent and non-covalent bonds to create artificial materials that respond to mechanical stimulation has only recently gained attention. Here we summarize our activities that mainly revolve around the exploitation of non-covalent interactions in (supramolecular) polymeric materials with the goal to translate mechanical stresses into useful, pre-defined events. Focusing on mechano- chromic polymers that alter their optical absorption or fluorescence properties, several new operating principles, mechanosensitive entities, and materials systems were developed. Such materials are expected to be useful for …

A New Generation Of Functional Polyisobutylenes For Advanced Applications, Corey M. Parada

Dissertations

Polyisobutylene (PIB) is a fully saturated, aliphatic polymer of high commercial importance due to its superior gas barrier properties and high chemical/oxidative stability. One commercial end-use for PIB is in insulated glass windows (IGU), where it acts as a gas/moisture barrier and sealant. Under certain adverse conditions, catastrophic failure of the PIB sealant may result in aesthetic and functional failure of the IGU, which necessitates replacement of the unit. Thus, there exists a need to improve current generations of thermoplastic PIB sealants to be able to withstand the harsh environments found in current real-world applications.

In the first project, we …

Polyhedral Oligomeric Silsesquioxane-Phosphate Glass Matrix Nanocomposites With Additional Chapter On Phosphate Glass-Poly(Ethylene Terephthalate) Matrix Composites, Kyoungtae Kim

Dissertations

Preparation and characterization of tin fluorophosphate glass (Pglass) matrix nanocomposites incorporating polyhedral oligomeric silsesquioxane (POSS) were investigated on the structural, thermal, morphological, mechanical, and rheological properties. Various processes including synthesis, extrusion and sintering processes were applied to prepare the nanocomposite samples. Another application of POSS with hydrophobic functional groups on the well-structured nanoscale silicate cage with three silanol groups was investigated to present the feasibility to use POSS molecule as a coating material on the surface of the hydrophilic inorganic glass. In addition, Poly(ethylene terephthalate) polymer matrix composites incorporating Pglass was studied to present the benefits of the Pglass with …

Effect Of Network Structure On Free Volume And Gas Transport Properties Of Thiol-Ene And Epoxy-Amine Networks, Ramesh Krishnan Ramakrishnan

Dissertations

Network parameters such as cross-link density or intermolecular interactions were used as effective parameters to control polymer chain packing or free volume and thereby control the mass transport properties of networks.

A series of polyethylene glycol (PEG) based thiol-ene elastomeric networks having a broad range of molecular weight between cross-links, M_c, (inverse of cross-link density) was prepared. The specific volume of the networks was studied as a function of temperature and pressure using high pressure dilatometry, and the obtained PVT data was fit using Simha-Somcynsky equation of state (S-S eos) analysis. Fractional free volume, quantified through S-S eos …

Structure-Property Relationships Of Solvent-Cast Organic Thin Films For Model Corrosion Control Coatings, Austin Maples

Dissertations

This dissertation aimed at answering several fundamental questions, specifically: 1) What is the effect of scribing parameters on visual corrosion assessments? 2) What role do molecular weight, residual solvent, and polymer composition have on morphological changes in organic thin films? 3) What alternatives to visual assessments could be implemented to better understand and detect corrosion before macroscopic failure? This research definitively proved that scribes can vary in type and dimensions, and yet are still comparable if the scribe dimensions before exposure are known. Furthermore, it demonstrated that solvents common to a variety of coating industries could become trapped within the …

Unexpected Effects Of Inorganic Phosphate Glass On Crystallization And Thermo-Rheological Behavior Of Polyethylene Terephthalate, Kyoungtae Kim, Shahab Kashani Rahimi, Todd M. Alam, Eric G. Sorte, Joshua U. Otaigbe

Faculty Publications

The effects of ultra-low glass transition temperature (T_g) phosphate glass (Pglass) on the thermal, morphological, rheological, mechanical, and crystallization properties of hybrid Pglass/poly(eththylene terephthalate)(PET) were investigated. Nano- and micro-scale distribution of the Pglass in the PET polymer matrix was observed. The polydispersed Pglass in the PET matrix functioned as a nucleation agent, resulting in increasing crystallization temperature. The Pglass in the PET matrix decreased the T_g, indicating a plasticizing effect of the Pglass in the hybrids that was confirmed by the significantly decreased complex viscosity of the PET matrix. In addition, with increasing temperature, a non-terminal …

Thermosetting Polymers Via Azide Alkyne Cycloaddition, Richard H. Cooke Iii

Dissertations

This dissertation exploits properties inherent to azide-alkyne cycloaddition and applies practical solutions to difficult problems. Chapter II addresses structure-property relationships in glassy azido-alkyne matrices by varying the identity of the central linkage within tetrapropargyl bis-aniline-type crosslinkers, and by the addition or omission of Cu(I) catalyst. This systematic study showed that an ether or methylene linkage yielded lower melting tetrapropargyl crosslinkers that were soluble in, and produced homogeneous, networks when cured with, a standard azido resin, di(3-azido-2-hydroxypropyl) ether of bisphenol-A; in contrast, a sulfone linkage yielded a relatively insoluble crosslinker and poorly dispersed, heterogeneous networks when reacted with the same …

Functional Emulsions Via Thiol-Ene Chemistry, Douglas Amato

Dissertations

Polymer particles (micro to nano) with tunable functionality have emerged as a promising and viable technology platform for applications including coatings, cosmetics, nanomedicine, and imaging. Unfortunately, the lengthy polymerization time and lack of intrinsic functionality in the monomers used to fabricate particles is an industrial challenge. Thiol-ene chemistry cirmcumvents these limitations with very rapid polymerization kinetics, high reaction yields, with supressed side reactions and inherent functionality. This dissertation demonstrates the utility of thiol-ene/yne polymerization in miniemulsion and microfluidics to generate functional materials in a one-pot-method. The functionality is typically generated via off-stoichiometry thiol-ene (OSTE) resins which allow for either excess …

Pro-Antimicrobial Networks Prepared Via Degradable Thiol-Ene Acetal Photopolymerization, Sarah Swilley

Honors Theses

A degradable, antimicrobial polymer network with acetal crosslink junctions derived from p-anisaldehyde (pA), a common constituent found in star anise extract, is reported. The p-anisaldehyde was converted into a bis-functional acetal alkene monomer, which serves as a pro-antimicrobial form of the active aldehyde and a building block for materials referred to as pro-antimicrobial polymer networks via degradable acetals (PANDAs). Subsequently, the bis-functional acetal alkene monomer was photopolymerized with a multifunctional thiol to yield a thiol-ene network. PANDAs exhibit surface erosion behavior and yield sustained release of pA over 38 days when exposed to neutral or biologically relevant conditions. The pA …

Biocompatible, Responsive Polysoaps Via Raft Copolymerization For The Delivery Of Model Cancer Therapeutics, Mason Dearborn

Honors Theses

Many chemotherapeutic drugs are small, hydrophobic molecules that require water-soluble, biocompatible nanocarriers for enhanced vascular circulation. Existing polymeric carriers either conjugate the drug along a copolymer backbone or sequester drugs within a protected interior domain to be delivered to specific sites in the body. Such therapeutic systems must overcome a myriad of hurdles, beginning with complex, multi-step syntheses, followed by other inherent barriers that limit the efficiency of drug delivery at the targeted site. This work aims to circumvent a number of these issues using biocompatible, stimuli-responsive polysoaps that are capable of unimeric micelle formation, hydrophobic drug delivery, and triggered …

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 …