Determination of Polymer Type and Comonomer Content in Polyethylenes by Pyrolysis−Photoionization Mass Spectrometry (original) (raw)
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Pyrolysis/mass spectrometry and pyrolysis/gas chromatography/mas spectrometry analysis of polymers
Rapid Communications in Mass Spectrometry, 1991
The potential of pyrolysis/gas chromatography/mass spectrometry in the study of the chemical composition and structure of polymers and copolymers is demonstrated, and results obtained on polysilane copolymers, phenolformaldehyde polycondensates and diol modified epoxy resins are presented. Temperatureltime-resolved pyrolysis mass spectrometry, carried out in the direct inlet of a mass spectrometer, revealed the presence of monomer and oligomer residues and of volatile additives in epoxy resin samples. Basic information was also obtained on the mechanism of thermal decomposition reactions in polysilane copolymers and diol modified epoxy resins.
Journal of Applied Polymer Science, 2018
ABSTACT: Poly(styrene-co-4-vinylpyridine) random copolymers with different molar composition were synthesized by nitroxidemediated controlled-radical polymerization using 2,2,5-trimethyl-4-phenyl-3-azahexane-3-nitroxide (TIPNO) as a mediator. We record the matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) spectra under various conditions, and we find (at last) that they show mostly intact ions [using 2(-4-hydroxyphenylazo-)benzoic acid as MALDI matrix]. Spectra are highly resolved, and thus they allow for the determination of all end-groups, even some less-abundant ones. Spectra are dominated by intact "dormant" copolymer chains terminated with TIPNO at one end and with (4-Bromo-phenyl)ethyl group (starting fragment) at the other one. Applying the mass analysis of copolymers (MACO) statistical model to the spectra, we show that the MACO/MALDI-TOF mass spectrometry (MS) analysis can be successfully applied to copolymers having a difference between the mass of the comonomers as small as 1 g mol −1 (the styrene and 4-vinylpyridine units are 104.15 and 105.15 g/mol, respectively), which results in overlapping isotopic patterns. The results are accurate: chemical composition evaluated by means of MS agrees with that calculated by 1 H-nuclear magnetic resonance, for all copolymers investigated. This analytical method allows to extract detailed information on the composition of the copolymer samples and their structure. Glass transition temperatures of copolymers were also determined by differential scanning calorimetry.
Journal of The American Society for Mass Spectrometry, 2011
A comprehensive study using liquid chromatography electrospray ionization multistage mass spectrometry (LC-ESI MS n ) was performed to get detailed structural information on poly(butylene adipate-co-butylene terephthalate) co-polyester and its product of partial degradation. LC-MS and LC-MS n identified the existence of cyclic structures in the original samples that disappear completely during the degradation. The occurrence of methanol transesterification in the degradation process was confirmed. MS 2 on the first 13 C isotope peak helped to determine the elemental composition of the fragments and facilitated end group determination. The method can be used to provide an alternative for high mass accuracy MS 2 experiments. Sequence information was also revealed for certain copolymeric structures.
Lc Gc North America
The analytical pyrolysis technique hyphenated to gas chromatography–mass spectrometry (GC–MS) has extended the range of possible tools for the characterization of synthetic polymers and copolymers. Pyrolysis involves thermal fragmentation of the analytical sample at temperatures of 500–1400 °C. In the presence of an inert gas, reproducible decomposition products characteristic for the original polymer or copolymer sample are formed. The pyrolysis products are chromatographically separated using a fused-silica capillary column and are subsequently identified by interpretation of the obtained mass spectra or by using mass spectra libraries. The analytical technique eliminates the need for pretreatment by performing analyses directly on the solid or liquid polymer sample. In this article, application examples of analytical pyrolysis hyphenated to GC–MS for the identification of different polymeric materials in the plastic and automotive industry, dentistry, and occupational safety are ...
Mass Spectrometry of Synthetic Polymers
Analytical Chemistry, 2004
The aim of this review is to give a compact overview about the literature on mass spectrometry (MS) of polymers published during 2006/2007. The citations are drawn from SciFinder January 25, 2008, using the search terms "poly*" and "mass spectrometry" with restrictions to review and journal contributions in the English language including refined searches in Web of Science. More than 750 relevant papers, reviews, (1, 2) and historical summaries were published in these two years, demonstrating the importance of MS for polymer analysis. We were therefore forced to select the most important references. This is always a subjective decision and may not always represent the best choices. In contrast to the previous review in this series (5), which focused on MS principles, including matrix-assisted laser desorption/ionization (MALDI) time-of-flight (TOF), electrospray ionization (ESI) TOF, TOF secondary ion mass spectrometry (SIMS), etc., in this paper, we categorize according to applications of MS for polymer analysis. Even this choice is arbitrary.
Analysis of polymers by mass spectrometry
Journal of Analytical and Applied Pyrolysis, 1987
Metastable mapping was applied to the analysis of the mixture of the pyrolysis products obtained from an aromatic polyamide, pyrolysed directly in a mass spectrometer. This technique permits a rapid analysis of the components and provides a method for assigning structures through the study of molecular ions, characteristic fragmentations and comparisons of daughter and parent ions of authentic samples. Collisionally activated decomposition spectra were always obtained in order to induce a higher intensity in the metastable transition. The thermal decomposition mechanism of the aromatic polyamide investigated here occurs via an intramolecular exchange and a concomitant N-H hydrogen transfer process with the formation of compounds with amine and/or succinimide end-groups.
Polymer Degradation and Stability, 2007
Pyrolysis products with mass of up to 850 Da were detected by direct pyrolysis mass spectrometric (DPMS) analysis of a series of copoly(arylene ether sulfone)s (PESePPO) synthesized by nucleophilic condensation of either 4,4 0 -dichlorodiphenylsulfone (CDPS) or 4,4 0 -bis-(4-chlorophenyl sulfonyl) biphenyl (long chain dichloride, LCDC) with different molar ratios of hydroquinone (HQ) or dihydroxydiphenylsulfone (HDPS). Pyrolysis products retaining the repeating units of the initial copolymers were formed at temperatures ranging from 420 C to 470 C (near the initial decomposition temperature). At temperatures higher than 450 C were observed products containing biphenyl units, formed by the elimination process of SO 2 from diphenyl sulfone bridges. Products having biphenyl and dibenzofuran moieties were detected in the mass spectra recorded at temperatures above 550 C. These units were formed by loss of hydrogen atom from diphenyl ether bridges. Although the EI (18 eV) mass spectra of the pyrolysis products of the samples investigated were very similar, it was found that the relative intensity of some ions reflects the molar composition of the copolymers analysed. Cyclic and linear oligomers with very low molecular mass, present in the crude copolymers, were also detected by DPMS. Thermogravimetric analysis also showed their excellent thermal stability below 400 C. It indicates that the copolymers yield a char residue of 40e45% at 800 C, which increases with the PPO mole fraction in the samples.
LC GC Europe
The analytical pyrolysis technique hyphenated to gas chromatography–mass spectrometry (GC–MS) has extended the range of possible tools for the characterization of synthetic polymers and copolymers. Pyrolysis involves thermal fragmentation of the analytical sample at temperatures of 500–1400 °C. In the presence of an inert gas, reproducible decomposition products characteristic for the original polymer or copolymer sample are formed. The pyrolysis products are chromatographically separated using a fused-silica capillary column and are subsequently identi" ed by interpretation of the obtained mass spectra or by using mass spectra libraries. The analytical technique eliminates the need for pretreatment by performing analyses directly on the solid or liquid polymer sample. In this article, application examples of analytical pyrolysis hyphenated to GC–MS for the identi" cation of different polymeric materials in the plastic and automotive industry, dentistry, and occupational s...
Application of mass spectrometry to the characterization of polymers
Current Opinion in Solid State and Materials Science, 1997
Recent advances in soft ionization techniques for mass spectrometry of polymeric materials make it possible to determine the mass of intact molecular ions exceeding 1 x 1 OS Da. Developments in high resolution mass spectrometers have additionally led to impressive advances in our ability to characterize polymers. The entire molecular mass distribution of a polymer sample can be accurately measured. From the molecular mass, the molecular formulae and information regarding polymer composition and end-groups can be deduced. The two techniques which have received the most attention are matrix-assisted laser desorption/ionization and electrospray ionization. In recent work, these techniques have been combined with chromatographic separations, and a series of mass spectra are acquired for each fraction of the distribution. This simplifies the analysis by reducing the number of components present in each mass spectrum, and additionally improves quantitation. Abbreviations ESI electrospray ionization FT-MS Fourier transform ion cyclotron resonance mass spectrometer MALDI matrix-assisted laser desorption/ionization SEC size exclusion chromatography TOF time-of-flight Kallos GJ, Tomalia DA, Hedstrand DM, Lewis S, Zhou J: Molecular weight determination of a polyamidoamine starburst polymer by electrospray-ionization mass spectrometry. Rapid Commun Mass Spectrom 1991, 6:383-386. McEwen CN, Simonsick WJ Jr, Larsen BS, Ute K, Hatada K: The fundamentals of applying electrospray ionization mass spectrometry to low mass poly(methyl methacrylate) polymers. J Am Sot Mass Spectrom 1995,6:906-911. Application of mass spectrometry to the characterization of polymers Jackson and Simonsick 667