Characterization of macromolecular systems by mass spectrometry and hyphenated techniques
The focus of this thesis was to gain in-depth structural information of synthetic polymers by the application of several combined techniques. The second chapter provides an overview about the influence of the polymer architecture on its characterization by mass spectrometry and complementary methods. In the third chapter, we demonstrate the use of MS, more specifically MALDI-ToF MS, which provides molar masses and dispersity values for poly(furfuryl glycidyl ether) (PFGE). The second example is the study of poly(N-isopropyl acrylamide) (PNiPAm) copolymers with glyco-monomers with specific combinations of matrices and cationization agents. The fourth chapter will combine three different examples regarding linear, star-shaped and hybrid polymers, which were analyzed by advanced techniques. The linear copolymers were analyzed by separating them according to their chemical heterogeneity using liquid absorption chromatography at critical conditions (LACCC) of poly(2-ethyl-2-oxazoline) (PEtOx), followed by automated spotting onto a MALDI target, which was subsequently analyzed by MALDI. Secondly, star-shaped polymers: [poly(ethylene oxide) (PEO)-b-PEtOx]8 were monitored firstly by using LACCC of linear PEO as first separation dimension and furthermore injected onto an SEC column confirming the molar mass. Lastly, a hybrid PEO star-shaped polymer was investigated using MALDI to verify the complete functionality of the core with PEO arms. Finally, the last chapter will focus on the creation of a software to obtain information regarding average composition, overcoming isotopic, overlapping peaks and isobaric species from MS spectra. Moreover, the quantitative studies were carried out by correction of the mass discrimination and isotopic abundance. Consequently, advanced analytical techniques such as different ionization techniques within MS, a range of chromatographic hyphenation and computational methods are implemented for elucidating the complexity of synthetic polymers.
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