Structural Characterization of Synthetic Polymers and Copolymers Using Multidimensional Mass Spectrometry Interfaced with Thermal Degradation, Liquid Chromatography And/or Ion Mobility Separation PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Structural Characterization of Synthetic Polymers and Copolymers Using Multidimensional Mass Spectrometry Interfaced with Thermal Degradation, Liquid Chromatography And/or Ion Mobility Separation PDF full book. Access full book title Structural Characterization of Synthetic Polymers and Copolymers Using Multidimensional Mass Spectrometry Interfaced with Thermal Degradation, Liquid Chromatography And/or Ion Mobility Separation by Nadrah Alawani. Download full books in PDF and EPUB format.
Author: Nadrah Alawani
Publisher:
ISBN:
Category : Chemistry
Languages : en
Pages : 238
Get Book Here
Book Description
This dissertation focuses on coupling mass spectrometry (MS) and tandem mass spectrometry (MS/MS) to thermal degradation, liquid chromatography (LC) and/or ion mobility (IM) spectrometry for the characterization of complex mixtures. In chapter II, an introduction of the history and the principles of mass spectrometry (MS) and liquid chromatography (LC) are discussed. Chapter III illustrates the materials and instrumentation used to complete this dissertation. Polyethers have been characterized utilizing tandem mass spectrometry (MS/MS), as presented in Chapter IV and Chapter VI. Diblock copolymers of polyethylene oxide and polycaprolactone, PEO-b-PCL, have been characterized by matrix-assisted laser desorption/ionization quadrupole/time-of-flight mass spectrometry (MALDI-Q/ToF) and LC-MS/MS (Chapter V). Thermoplastic elastomers have been characterized by thermal degradation using an atmospheric solids analysis probe (ASAP) and ion mobility mass spectrometry (IM-MS), as discussed in Chapter VII. Interfacing separation techniques with mass spectrometry permitted the detection of species present with low concentration in complex materials and improved the sensitivity of MS. In chapter IV, the fragmentation mechanisms in MS/MS experiments of cyclic and linear poly(ethylene oxide) macroinitiators are discussed. This study aimed at determining the influence of end groups on the fragmentation pathways. In the study reported in Chapter V, ultra high performance liquid chromatography (UHPLC) was interfaced with MS and MS/MS to achieve the separation and in-depth characterization and separation of amphiphilic diblock copolymers (PEO-b-PCL) in which the architecture of the PEO block is linear or cyclic. Applying UPLC-MS and UPLC-MS/MS provides fast accurate information about the number and type of the blocks in the copolymers. Chapter VI reports MS/MS and IM-MS analyses which were performed to elucidate the influence of molecular size and collision energy on the fragmentation pathways of polyethers subjected to collisionally activated dissociation (CAD). Survival yields and collision cross-sections were derived for several oligomers of polybutylene oxide (PBO) and polytetrahydrofuran (PTHF) polymers by MS/MS and IM-MS, in order to understand their fragmentation energetics and fully characterize their structures. In Chapter VII, application of atmospheric solids analysis probe (ASAP) and ion mobility (IM) separation were coupled with mass spectrometry (MS) and tandem mass spectrometry (MS/MS) to characterize commercially available thermoplastic elastomers. These compounds are mainly composed of thermoplastic copolymers, but also contain additional chemicals to enhance their properties or to protect them from degradation. Using ASAP-IM-MS enables fast analysis, involving mild degradation at atmospheric pressure (ASAP) and subsequent characterization of the desorbates and pyrolyzates by ion mobility mass spectrometry (IM-MS) and tandem mass spectrometry (MS/MS). Such multidimensional dispersion considerably simplifies the resulting spectra, permitting the conclusive separation and characterization of the multicomponent materials examined. Chapter VIII summarizes the findings of this dissertation and is followed by appendices with supplemental data and the copyright permissions obtained for this dissertation.
Author: Nadrah Alawani
Publisher:
ISBN:
Category : Chemistry
Languages : en
Pages : 238
Get Book Here
Book Description
This dissertation focuses on coupling mass spectrometry (MS) and tandem mass spectrometry (MS/MS) to thermal degradation, liquid chromatography (LC) and/or ion mobility (IM) spectrometry for the characterization of complex mixtures. In chapter II, an introduction of the history and the principles of mass spectrometry (MS) and liquid chromatography (LC) are discussed. Chapter III illustrates the materials and instrumentation used to complete this dissertation. Polyethers have been characterized utilizing tandem mass spectrometry (MS/MS), as presented in Chapter IV and Chapter VI. Diblock copolymers of polyethylene oxide and polycaprolactone, PEO-b-PCL, have been characterized by matrix-assisted laser desorption/ionization quadrupole/time-of-flight mass spectrometry (MALDI-Q/ToF) and LC-MS/MS (Chapter V). Thermoplastic elastomers have been characterized by thermal degradation using an atmospheric solids analysis probe (ASAP) and ion mobility mass spectrometry (IM-MS), as discussed in Chapter VII. Interfacing separation techniques with mass spectrometry permitted the detection of species present with low concentration in complex materials and improved the sensitivity of MS. In chapter IV, the fragmentation mechanisms in MS/MS experiments of cyclic and linear poly(ethylene oxide) macroinitiators are discussed. This study aimed at determining the influence of end groups on the fragmentation pathways. In the study reported in Chapter V, ultra high performance liquid chromatography (UHPLC) was interfaced with MS and MS/MS to achieve the separation and in-depth characterization and separation of amphiphilic diblock copolymers (PEO-b-PCL) in which the architecture of the PEO block is linear or cyclic. Applying UPLC-MS and UPLC-MS/MS provides fast accurate information about the number and type of the blocks in the copolymers. Chapter VI reports MS/MS and IM-MS analyses which were performed to elucidate the influence of molecular size and collision energy on the fragmentation pathways of polyethers subjected to collisionally activated dissociation (CAD). Survival yields and collision cross-sections were derived for several oligomers of polybutylene oxide (PBO) and polytetrahydrofuran (PTHF) polymers by MS/MS and IM-MS, in order to understand their fragmentation energetics and fully characterize their structures. In Chapter VII, application of atmospheric solids analysis probe (ASAP) and ion mobility (IM) separation were coupled with mass spectrometry (MS) and tandem mass spectrometry (MS/MS) to characterize commercially available thermoplastic elastomers. These compounds are mainly composed of thermoplastic copolymers, but also contain additional chemicals to enhance their properties or to protect them from degradation. Using ASAP-IM-MS enables fast analysis, involving mild degradation at atmospheric pressure (ASAP) and subsequent characterization of the desorbates and pyrolyzates by ion mobility mass spectrometry (IM-MS) and tandem mass spectrometry (MS/MS). Such multidimensional dispersion considerably simplifies the resulting spectra, permitting the conclusive separation and characterization of the multicomponent materials examined. Chapter VIII summarizes the findings of this dissertation and is followed by appendices with supplemental data and the copyright permissions obtained for this dissertation.
Author: Bryan C. Katzenmeyer
Publisher:
ISBN:
Category : Chemistry
Languages : en
Pages : 301
Get Book Here
Book Description
This dissertation focuses on utilizing mass spectrometry (MS) and tandem mass spectrometry (MS/MS), combined with the coupling of liquid chromatography (LC) and/or ion mobility (IM) spectrometry, to characterize polymeric materials. Chapter II will introduce history and basic principles of mass spectrometry and liquid chromatography including background on instrumentation and theory. Chapter III will discuss the materials and instrumentation used in the various projects. Chapters IV-VII are research project chapters as described below. Lastly, Chapter VIII concludes this dissertation with a summary. Following the last chapter are appendices with supplemental data and copyright permissions for this dissertation. Chapter IV details the characterization of two nonionic surfactants consisting of a methoxylated glucose core (glucam) that was either chain-extended with ethylene oxide and then esterified with stearic acid to generate poly(ethylene oxide) glucam stearate(s) or only esterified with stearic acid which made glucam stearate(s). The use of LC-MS, LC-MS/MS, IM-MS, and MS/MS made it possible to separate and determine the compositions for each component in the mixtures resulting from the synthesis of these amphiphilic polymers. Components of (PEO)n-glucam stearate(s) were readily separated by their hydrophobicity and degrees of esterification by LC-MS and IM-MS. Each method offers complementary information, with LC-MS excelling in the separation and characterization of highly hydrophobic amphiphilles and IM-MS provides a quicker analysis of minor trace components. Electron transfer dissociation (ETD) was also applied as a novel MS/MS application to poly(ethylene oxide) glucam stearate(s). However, when compared to traditional MS/MS activation techniques (collisionally activated dissociation (CAD)), ETD unveiled no significant structural information when compared to CAD activation of the same oligomer. Specifically, ETD caused no unique cleavages across the sugar core as seen in oligosaccharide systems. In Chapter V, several homopolymers of poly(dimethylsiloxane) (PDMS) with different polymer end groups were studied by MS/MS. Detailed CAD mass spectra of PDMS homopolymers containing [alpha, omega] -bis(hydroxyl)-, [alpha, omega] -bis(3-aminopropyl)-, and [alpha, omega] -bis(ethoxy)- end groups are reported herein. MS/MS spectra indicate that chargeremote intramolecular rearrangements, H-atom abstraction, and intramolecular nucelophilic substitutions give rise to the fragments seen from the PDMS polymers studied. PDMS end groups are found to significantly influence the fragmentation pathways of energetically excited precursor ions from these type of polymers. Chapter VI of this dissertation discusses the MS and MS/MS characterization of several poly(phosphazene)s. Higher order cyclic poly(dichlorophosphazene)s and poly(bis(phenoxy)phosphazene) were analyzed. The MS/MS fragmentation pattern of poly(bis(phenoxy)phosphazene) indicated that this polymer had a tadpole architecture. Based on both the positive and negative ion MS/MS data, lateral chain fragmentation dominates in all cases and losses of bis(phenoxy)phosphazene are observed from oligomers having a tale larger than the trimer. Only in negative mode can the cyclic trimer ring open via charge-induced dissociation and expel one unit of bis(phenoxy)phosphazene. These data provide strong additional evidence that these polymers form a tadpole architecture. Lastly, in Chapter VII three polyesters were studied. Two homopolymers, poly(lactide) (PLA) and poly(glycolide) (PGA), and one copolymer, poly(lactide-coglycolide) (PLGA). Oligomers of PLA undergo a series of 1,5-hydrogen rearrangement (1,5-rH) reactions. Whereas oligomers of PGA fragment via intramolecular transesterifications. The PLGA copolymer was found to contain cyclic and linear (with HO- and -H end groups) copolymers. Fragmentation proceeded via 1,5-rH reactions that opened the cyclic copolymer and intramolecular transesterifications. In the case of linear copolymers containing at least two glycolide units, the MS/MS spectra provide direct information on the block length of each monomer.
Author: Nilüfer Solak
Publisher:
ISBN:
Category : Chemistry, Analytic
Languages : en
Pages : 221
Get Book Here
Book Description
"This dissertation focuses on coupling liquid chromatography (LC) and/or ion mobility (IM) spectrometry to mass spectrometry (MS) and their application to characterization of complex mixtures. Fatty acid ethyl esters (FAEEs) in meconium, polyethylene oxide (PEO) copolymers, the nonionic surfactant Polysorbate 85, and poly(butylene adipate) were characterized by LC-MS[superscript n] and/or IMMS[superscript n]. Coupling of a separation technique to mass spectrometry improves the sensitivity of MS, thus permitting the detection of species present in low concentration. FAEEs are metabolites of ethanol. They are formed by nonoxidative metabolization of ethanol. FAEEs accumulate in various tissues. Ethanol can easily penetrate the placenta and results in the formation and deposition of FAEEs in fetal tissues including meconium. Therefore, FAEEs may be used as biomarkers for heavy alcohol consumption during pregnancy. In the first chapter of this dissertation (chapter 4), FAEEs were extracted from meconium and analyzed by LC-MS to determne the amount of ethyl linoleate, ethyl oleate, and ethyl palmitate. Among the fifty samples run, two were from mothers who had admitted alcohol consumption during pregnancy and those samples were found to contain high amounts of ethyl linoleate and ethyl palmitate. In the follow chapter of this dissertation (chapter 5), tandem mass spectrometry analyses were performed on PEO oligomers to elucidate their fragmentation pathways. These mechanisms derived the structural elucidation of the PEO copolymers analyzed by LC-MS[superscript n] in subsequent studies, as itemized below. In chapter 6, different chain lengths of a PEO-poly(propylene oxide) (PPO) triblock and a PEO-PPO random copolymer was separated and identified by LC-MS[superscript n]. Separation of the oligomers were based on their propylene oxide (PO) content. Oligomers with higher PO content had longer retention times. A putative PEO-poly(dimethylsiloxane) block copolymer was also investigated; in this case, unexpected minor byproducts/starting materials which could not be observed by MS were detected and identified using the LC-MS[superscript n] technique. Chapter 7 focuses on the LC-MS[superscript n] characterization of a commercial surfactant, Polysorbate 85. It is composed of many species with different degrees of esterification. Some of those species have identical nominal masses which complicates their characterization by MS. Therefore, a separation technique is needed prior to MS analysis. Reverse phase LC separated the oligomers based on their hydrophilicity/hydrophobicity. In addition, LC-MS2 experiments unveiled the esterification degree of the oligomers. A novel technique, IMMS, was also employed for characterization of the constituents of Polysorbate 85. IMMS disperses ions according to their collision cross sections and charge states. Oligomers with a different number of ester moieties could be separated and identified. Finally, Chapter 8 reports how IMMS was used to disperse and characterize linear and cyclic poly(butylene adipate) oligomers. The separation of the oligomers was based on their charge states. IMMS improved the sensitivity of MS and permitted the detection of +3 and +4 charged ions which were undetectable in the single-stage mass spectrum."--Abstract.
Author: Christopher Barner-Kowollik
Publisher: John Wiley & Sons
ISBN: 3527641831
Category : Science
Languages : en
Pages : 501
Get Book Here
Book Description
Combining an up-to-date insight into mass-spectrometric polymer analysis beyond MALDI with application details of the instrumentation, this is a balanced and thorough presentation of the most important and widely used mass-spectrometric methods. Written by the world's most proficient experts in the field, the book focuses on the latest developments, covering such technologies and applications as ionization protocols, tandem and liquid chromatography mass spectrometry, gas-phase ion-separation techniques and automated data processing. Chapters on sample preparation, polymer degradation and the usage of mass-spectrometric tools on an industrial scale round off the book. As a result, both entrants to the field and experienced researchers are able to choose the appropriate methods and instrumentations -- and to assess their respective strengths and limitations -- for the characterization of polymer compounds.
Author: Madalis Casiano-Maldonado
Publisher:
ISBN:
Category : Biodegradation
Languages : en
Pages : 178
Get Book Here
Book Description
The characterization of synthetic polymers and complex oligomeric mixtures by a combination of different mass spectrometry (MS) techniques is the main topic of this dissertation. Ion mobility (IM) separation and/or tandem mass spectrometry (MS2) were interfaced with single stage mass spectrometry for the fast, complete, precise and accurate characterization of different polymers, biopolymers, and biodegradation products. Additionally, the development of a mass spectrometry protocol for the quantitation of proteins adsorbed on different polymer surfaces was accomplished in this dissertation. Over the passed years, synthetic routes for the creation of PEGs have been modified by the elimination of organic catalysts and solvents and the application of green chemistry for the generation of new polymers. In Chapter 4 of this dissertation, MS and MS2 were employed, as the main analytical techniques, for the structural elucidation of enzyme-catalyzed, functionalized PEG and tetraethylene glycol (TEG) biomaterials. The samples analyzed were synthesized by two different processes, transesterification and Michael addition reactions, both of them using CALB as the catalyst. In Chapter 5 of this dissertation, polylactide was degraded using Proteinase K and its biodegradation products were analyzed by MS and MS2. Elucidation of its degradation products is important to the biomedical community; knowledge of these products helps to see any toxicity problems with the use of this polymer. The MS and MS2 results showed that the degradation products are short polylactide chains, down to the monomer. No other, potentially dangerous organics were detected. In the following chapter of this dissertation (Chapter 6), the adsorption of three model proteins onto two different surfaces was evaluated over a pH range. The results were explained on terms of polymer chemistry, surface morphology, proteins' isoelectricpoints and molecular dimensions. Finally, Chapter 7 reports how derivatization, degradation, or chromatographic separation can be avoided for the analysis of complex systems, if multidimensional mass spectrometry methods combining ion mobility separation and different ionization techniques are employed. Using this new approach complex poly([alpha]-peptoid) samples were characterized. The results showed that the main product in the system contained the N-heterocyclic carbene (NHC) moiety that served as ring-opening polymerization catalyst. Furthermore, it was demonstrated that elimination of the NHC segment leads to cyclic poly([alpha]-peptoid)s that have very similar conformations with comparably sized polypeptides.
Author: Harald Pasch
Publisher: Springer Science & Business Media
ISBN: 3662050463
Category : Science
Languages : en
Pages : 312
Get Book Here
Book Description
MALDI-TOF mass spectrometry is one of the latest and most fascinating new developments in the analysis of organic compounds. Originally developed for the analysis of biomolecules, it has developed into one of the most powerful techniques for the characterization of synthetic polymers. This book describes the fundamentals of the MALDI process and the technical features of MALDI-TOF instrumentation. It reviews the application of MALDI-TOF for identification, chemical and molar mass analysis of synthetic polymers. With many examples, the monograph examines experimental protocols for the determination of endgroups, the analysis of copolymers and additives, and the coupling of liquid chromatography and MALDI-TOF in detail.
Author: Muhammad Imran Malik
Publisher: Springer Nature
ISBN: 3031348354
Category : Technology & Engineering
Languages : en
Pages : 310
Get Book Here
Book Description
This book elucidates the peculiar phenomenon of entropy/enthalpy compensation that takes place in high performance liquid chromatography (HPLC) of polymers. Numerous publications, including some books, are devoted to molecular characterization of synthetic polymers, materials presently produced in large and steadily growing quantities, applying methods of HPLC. A knowledge of the molecular characteristics of polymers is indispensable, not only for their proper applications but also for their recycling and remediation. Polymer scientists generally focus on synthesis and potential applications of polymers while not giving due attention to an important central link, their comprehensive characterization in context of development of structure-property correlations. To fill this gap is one of the aims of the present book. The process of entropy/enthalpy compensation plays a decisive role in the advanced method of polymer characterization such as liquid chromatography at critical conditions, eluent gradient interaction chromatography, and temperature gradient interaction chromatography. All chemists working on any aspect of polymer science will find this book a valuable resource for the development of structure-property correlations.
Author: Savannah R. Snyder
Publisher:
ISBN:
Category : Mass spectrometry
Languages : en
Pages : 146
Get Book Here
Book Description
The following dissertation focuses on utilizing mass spectrometry (MS) and its hyphenated techniques to understand the structure-property relationships of various stimuli-responsive polymers. By exploiting these materials' reactions to an outside stimulus, parallels can be made between the information from the mass spectral analyses and the materials' physical properties. Using techniques like tandem mass spectrometry (MS/MS), liquid chromatography (LC), and ion mobility (IM), properties of these materials were correlated to their microstructures and resultant physical functionalities. Side-chain liquid crystalline (SCLC) homopolymers and copolymers are a type of stimuli-responsive macromolecule that respond to incident light. The side-chains are generally comprised of oxygen, nitrogen, phenyl rings, etc., making their resulting structures conjugated systems. These properties allow them to polarize light. They are used in various optical applications as these mesogenic (i.e., liquid crystalline) side chains give the molecules optical anisotropy. These side-chains are what control the physical properties of these polymers and when two different types of liquid crystalline side chains are polymerized, the resultant copolymer can have vastly different properties than their respective homopolymers. Additionally, the sequence of the side-chains being random, block, alternating, or tapered also affects the physical properties. The copolymers in this study were synthesized with oxiranemethanol reacted with the mesogenic side-chains (4-cyano-4'hydroxybiphenyl, 4-[4'-pentylcyclohexyl]phenol) through a four carbon linker. Using matrix-assisted laser desorption/ionization-tandem mass spectrometry (MALDI-MS/MS) via laser-induced fragmentation (LIFT) allowed for the sequences of the designed SCLC copolymers to be identified. Particulate accumulation and deposition in the in-take valve of a vehicular engine can be the cause of many engine issues, though the cause of this buildup is not well studied. Using mass spectrometry to analyze these deposits can give insight into what they are comprised of, how they were made, and potentially, how to prevent them. Oils and fuels can mix with the air in the presence of harsh engine conditions to cause such deposits, but the formulations have components in them intended to deter this unwanted product, like detergents, dispersants, viscosity modifiers, etc. Oftentimes, these additives are low molecular weight polymers that respond to an increase in temperature, or another stimulus, aiding in the engine's cleanliness and maintenance. The more polar constituents in these blends are thought to contribute to these deposits, and also makes them more amenable to mass spectral analysis. Mass spectrometry and a variety of its hyphenated techniques (ASAP-, LC-, IM-) were used to acquire insight into the composition of these unknown samples to potentially aid in their preclusion.Finally, thermoresponsive polymers (TRPs) are stimuli-responsive polymers that alter their architecture when subjected to energy in the form of heat. They are used in biological applications for drug delivery, vehicular applications in fuels, and various other temperature-sensitive practices. The ability to change conformation in response to temperature aids in the herein studied samples' biological applications by changing hydrophobicity for sensitive biotic needs. These alterations are essentially changes to the conformation of the polymer chain itself, and generally are produced from p-NIPAM-like and methacrylate-like polymers. In order to observe this change, ion mobility-mass spectrometry (IM-MS) was used in a novel analysis to detect changes in polymer architecture when stimulated by increasing collision energy (collisional heating). The energy was then correlated to the varying pendant structures of the polymers, which showed a direct structure-property relationship between energy needed for conformational change and overall hydrophilicity/bulkiness.
Author: Minna Hakkarainen
Publisher: Springer Science & Business Media
ISBN: 3642280412
Category : Technology & Engineering
Languages : en
Pages : 219
Get Book Here
Book Description
Emerging Mass Spectrometric Tools for Analysis of Polymers and Polymer Additives, by Nina Aminlashgari and Minna Hakkarainen. Analysis of Polymer Additives and Impurities by Liquid Chromatography/Mass Spectrometry and Capillary Electrophoresis/Mass Spectrometry, by Wolfgang Buchberger and Martin Stiftinger. Direct Insertion Probe Mass Spectrometry of Polymers, by Jale Hacaloglu Mass Spectrometric Characterization of Oligo- and Polysaccharides and Their Derivatives, by Petra Mischnick. Electrospray Ionization-Mass Spectrometry for Molecular Level Understanding of Polymer Degradation, by Minna Hakkarainen.
Author: Liang Li
Publisher: John Wiley & Sons
ISBN: 0470567228
Category : Science
Languages : en
Pages : 325
Get Book Here
Book Description
Principles and Practices of Polymer Mass Spectrometry helps readers acquire the skills necessary for selecting the optimal methods, handling samples, analyzing the data, and interpreting the results of the mass spectrometry of polymers. This guide describes the principles of polymer MS and best practices in polymer characterization. It discusses different approaches, including MALDI, ESI, TOF MS, and FT-MS. It provides a guide to developing appropriate sample preparation protocols for different polymers. Complete with examples of applications and experiments, this is an excellent reference for scientists, researchers, graduate students, and others.
