For centuries chemists have sought to improve humankind’s quality of life and address many of society’s most pressing needs through the development of chemical processes and synthesis of new compounds, often with phenomenal results. Unfortunately, there also are many examples where these chemicals have had unintended, detrimental consequences that are not apparent until years or decades after their initial use. There are numerous halogenated molecules in this category that are globally dispersed, resistant to natural degradation processes, bioaccumulative, and toxic to living organisms. Chemicals such as these are classified as persistent organic pollutants (POPs), and due to their negative environmental and health effects, they require safe, effective, and inexpensive means of remediation. This research focuses on the development and optimization of a reaction matrix capable of reductively dehalogenating several POPs. Initial experiments determined that powdered magnesium and 1% V/V acetic acid in absolute ethanol was the most effective system for degrading polychlorinated biphenyl (PCB), an extraordinarily recalcitrant environmental contaminant. Further studies showed that this matrix also was capable of degrading polychlorinated dibenzo-p-dioxins (PCDDs), polybrominated diphenyl ethers (PBDEs), and four organochlorine pesticides (OCPs); dieldrin, heptachlor, heptachlor epoxide, and chlordane. During this phase of testing, field samples contaminated with chlordane were washed with ethanol and this ethanol/chlordane solution was degraded using the same reaction matrix, thereby demonstrating this technology’s potential for “real-world” remediation projects. Finally, a set of experiments designed to provide some insight into the mechanism of dechlorination seems to indicate that two distinct processes are necessary for degradation to occur. First, the passivated iv outer layer of the magnesium must be removed in order to expose the zero-valent magnesium core. Next, an electron is transferred from the magnesium to the target molecule, causing the cleavage of the halide bond and the subsequent abstraction of either a hydrogen or proton from a solvent molecule. It is anticipated that an understanding of these fundamental chemical processes will allow this system to be tailored to a wide range of complex environmental media

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Polyesters are an attractive class of polymer that can be readily modified with a wide range of different comonomers, during polymerization or with melt blending, to achieve a wide variety of physical properties. This research primarily focuses on polyesters that incorporate rigid aromatic structures that have excellent potential to enhance thermal and mechanical properties. Copolyesters were prepared through melt polycondensation of diesters and diols in the presence of an exchange catalyst. Monomer incorporation was verified with nuclear magnetic resonance (NMR) and molecular weights were obtained by measuring inherent viscosity (ninh). Physical properties were assessed with thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and rheology. Mechanical properties were assessed with tensile and impact testing. Copolyesters of poly(ethylene terephthalate) (PET) were synthesized by substituting dimethyl terephthalate (DMT) with dimethyl 4,4'-biphenyldicarboxylate (4,4'BB) resulting in enhanced glass transition (Tg) temperatures relative to PET while affording melting temperatures (Tm) low enough to allow facile melt processing. Further modification with dimethyl isophthalate (DMI) or dimethyl 3,4'-biphenyldicarboxylate (3,4'BB) slowed crystallization sufficiently to allow biaxial orientation, leading to further studies assessing the permeability of oriented films. Novel amorphous polyesters were synthesized with 3,4'BB or 4,4'BB in combination with neopentyl glycol (NPG), 1,4-cyclohexandimethanol (CHDM) and ethylene glycol (EG). Use of multiple diols produced clear, amorphous copolyesters with Tgs as high at 129 C. A series of novel high temperature(Tm) copolyesters were synthesized from dimethyl 2,6-naphthalenedicarboxylate (DMN) and 4,4'BB combined with CHDM. Studies were performed with standard DSC and thin film calorimetry to show the convergence of multiples melting endotherms in an effort to determine their origin. Preliminary work was performed on the modification of poly(1,4-cyclohexylenedimethylene terephthalate) (PCT), poly(1,4-cyclohexylenedimethylene 2,6-naphthalate) (PCN) and poly(1,4-cyclohexylenedimethylene 4,4'-bibenzoate) (PCB) with dimethyl p-terphenyl-4,4''-dicarboxylate. / PHD / Polyesters have a unique balance of properties that sets them apart from other polymers formed by step growth reactions. The transesterification reaction that forms polyesters occurs continually at reaction temperatures, making it easy to randomly distribute a mixture of different comonomers along the backbone during the polymerization process, or even when blending two different polyesters. Poly(ethylene terephthalate), commonly referred to as PET, is the most important polyester currently in production, and is prized for its transparency, chemical resistance, and recyclability. PET was first made by John Whinfield and James Dickson at Calico Printers’ Association of Mansfield, in 1941 and was eventually licensed to DuPont in the 1970s. It has since become a valuable resource for producing synthetic textiles and replacing heavier materials, such as glass and metal, to produce lightweight containers, especially for food storage. Many of the polyesters, such as PET, that we see on a daily basis are actually copolyesters that contain low levels of additional comonomers that have been added to improve some property of the final polymer or to facilitate processing. In research, modification of polyesters with different comonomers broadens our understanding in how the molecular structure of comonomers affects polyester properties. This makes it possible to tune a copolyester’s physical properties in a way that can enhance its suitability for a wide range of applications. The research described in this dissertation is focused on exploring how rigid monomer structures containing multiple aromatic rings might be used to produce polyesters with improved performance relative to current commercial polyesters. Materials that demonstrate good barrier to gases such as CO₂ and O₂ are important for packaging that can seal in and preserve food and beverages. In our research, we modified PET with bibenzoate structures to produce films that showed improved gas barrier when stretched in a manner that imitates the stretch blow molding process used to produce bottles. These materials showed good promise for packaging capable of preserving food for longer periods of time. Clear, food safe plastics that do not deform at the boiling temperature of water are important for baby bottles and durable dishwasher safe containers, which are commonly sterilized with boiling water. Until recently, such materials were produced from bisphenol-A polycarbonate (BPA PC), which fell out of favor for food safe applications over concerns that BPA, believed to have endocrine disrupting activity, may leach into food and beverages. Bibenzoate monomers, which increases the application temperature of many polyesters, were combined with different combinations of diol monomers to produce transparent copolyesters that are usable at higher temperatures. These materials demonstrated excellent potential as food safe alternatives to BPA containing materials. Crystalline plastics that resist distorting at high temperatures are important for applications in the electronics and automotive industry. Semicrystalline polyesters provide less expensive alternatives to the costly liquid crystalline polymers commonly used for high temperature applications. We explored the properties of a number of semicrystalline copolyester compositions capable of exceeding the application temperature of semicrystalline polyesters currently on the market.

This thesis describes the creation of RECOVERY-RD, a numerical model capable of representing the biotransformation processes associated with Polychlorinated Biphenyl (PCB) compounds in contaminated sediments for a variety of aquatic environments, including rivers and marine systems. RECOVERY-RD is intended as a screening tool for evaluating the impact of engineered sediment caps on contaminant remediation. The two key components that provided the framework for RECOVERY-RD are RECOVERY, a model for contaminant transport in stratified sediment, and SEAM3D, a numerical transport model for contaminated groundwater systems. The predictions made by RECOVERY-RD are verified using a series of test cases organized to test each phase of the modification process individually. The results show that the processes simulated by RECOVERY-RD are reasonably represented when compared to alternative calculation methods that have been previously verified. A hypothetical application of the initial version of the model provides evidence of the usefulness as a screening-level tool for the assessment of remedial efficacy. / Master of Science

Polychlorinated Biphenyls (PCBs) are persistent organic pollutants known for their toxicological effects. Though industrial production of legacy PCBs was banned in 1977, they can still be measured in nearly all environmental matrices. The Chicago Sanitary and Ship Canal (CSSC) is lined with industry and the receiving waters to the Stickney Water Reclamation Plant, the World's largest waste water treatment plant and was therefore speculated to be a potential source of PCBs to the Greater Chicago Area. Surficial sediment samples were acquired along a 45 km stretch of the CSSC, from Kedzie Ave. to Lockport. PCBs in the bulk sediment were extracted using accelerated solvent extraction while PCBs in the porewater were extracted using solid phase micro extraction. The PCBs were identified and quantified using a variation on EPA method 1668C. A total of 176 individual and coeluting PCBs were identified and quantified in this study. The sum of PCB concentrations in the bulk sediment was found to range from 70 to 4970 ng/g dry wt. The sum of PCB concentrations in the freely dissolved sediment-porewater was found to range from 2 to 366 ng/L. The bulk and porewater concentrations were used to estimate an average mass flow rate of PCBs through the CSSC of 368 kg/y. The large mass flow rate of PCBs passing through the CSSC and the fact that the CSSC connects Lake Michigan to the Mississippi River suggest that continued monitoring of PCB concentrations are necessary to better understand the transport and fate of PCBs in and out of the Great Chicago Area.

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This Thesis aims to examine the effects of substituents on the adjacent proton accepting phenyl ring with respect to a new type of excited state intramolecular proton transfer (ESIPT) process discovered by Wan and co-workers. Therefore, a number of 2-phenylphenols 23-28 were synthesized with electron-donor and electron-acceptor substituents such as methyl, methoxy, and ketone moieties on the adjacent proton accepting phenyl ring. The results obtained from examination of photochemical deuterium exchange showed that all derivatives except for ketone 27 underwent deuterium exchange (Фex = 0.019 - 0.079), primarily at the 2’-position on photolysis in D2O-CH3CN. In general, compounds with methoxy moiety (ies) on the adjacent proton accepting ring showed higher deuterium exchange yields. Diol 28 has the potential to undergo photosolvolysis as well as ESIPT process since it has both a benzyl alcohol and a phenol chromophore on the same molecule. Irradiation of 28 in 1:1 H2O-CH3OH gave the corresponding methyl ether product in high yield. Photolysis of 28 in 1:1 D2O-CH3OH also showed that ESIPT competes very well with photosolvolysis. Thus, this work has established that ESIPT can compete efficiently with photosolvolysis. Semi-empirical AM1 (examination of HOMOs and LUMOs) calculations show a large degree of charge transfer in the electronic excited state (except 27), from the phenol ring to the attached phenyl ring of the studied compounds. The AM1 calculation for ketone 27 showed that the carbonyl oxygen is more basic than the carbon atoms of the benzene ring, which explains the lack of deuterium exchange observed for 27.

An enantioselective heart-cut two-dimensional liquid chromatography-atmospheric pressure photoionization-tandem mass spectrometry method was developed for the analysis of 25 methylsulfonyl polychlorinated biphenyl metabolites in tissue extracts. Enantioseparation was achieved for 9 out of the 10 chiral analytes in less than 91 minutes, improving upon previous gas chromatography-based methods. Use of a pyrenyl-ethyl silica column in the first dimension enabled separation of all but two pairs of isobaric analytes. Limits of detection of 0.01 to 1.73 ng on-column were achieved. The precision and accuracy were within acceptable limits, but poor sensitivity was achieved for several meta-methylsulfonyl-substituted congeners. Despite this limitation, the method was successfully applied to the analysis of Greenland sledge dog (Canis familiaris) plasma and adipose tissue extracts. Concentration and enantiomer fraction data are presented. None of the target analytes were detected in Norwegian glaucous gull (Larus hyperboreus) plasma extracts.

Steroid hormones in testis play an important role in spermatogenesis, maintenance of the male reproductive tract, production of semen and the maintenance of secondary sex characteristics and libido. They are also discussed as a target for substances called endocrine disruptors (EDs). No complex study was conducted on evaluation of relationships between EDs and steroid spectrum in 2 biological fluids; seminal plasma and plasma. The aim of the PhD. thesis was to develop and validate a method for determination of bisphenol A (BPA) and steroid spectrum in plasma and seminal plasma and to shed more light into mechanisms of ED action and effects of BPA and polychlorinated biphenyls (PCBs) on human spermatogenesis and steroidogenesis. Two new liquid-chromatography mass spectrometry methods for determination of BPA and 11 steroids in plasma and seminal plasma were developed and validated. The methods were used for estimation of analyte concentrations in 191 men with a different degree of fertility. Concurrently, the levels of six congeners of PCBs, gonadotropins, selenium and zinc in plasma were estimated. Partial correlations adjusted for age and BMI were calculated to evaluate relationships between these analytes. Seminal BPA, but not plasma BPA, was negatively associated with sperm concentration...