Characterization of Randomly Branched Polymers Utilizing Liquid Chromatography and Mass Spectrometry
Branching in polymers is an important way to modify the materials properties, however the characterization of random branching in polymeric materials is a challenge in polymer analysis. In this work, liquid adsorption chromatography methods are developed for a commercially available hyperbranched polyester (BoltornTM). This chromatographic techniques was then coupled to offline MALDI-TOF MS analysis, a first in the analysis of randomly branched polymers. The coupling of these two techniques provides superior MALDI-TOF spectra, enabling the easy identification of structural subdistributons based on theoretical molecular weight. Detailed analysis of the MALDI-TOF spectra shows that these chromatographic conditions separate cyclic Boltorn polymers (with no core molecule) from non-cyclic polymers (with core molecule), and these are the only two architectures observed. MALDI MS also confirms that the chromatographic separation mode is adsorption, but further analysis is needed to determine if there is a separation by degree of branching.
KeywordsHyperbranched polyesters Polymer mass spectrometry Polymer chromatography Liquid adsorption chromatography MALDI-TOF MS
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Bianka Manger (HPLC) and Rosemarie Laging (MALDI-TOF MS) are thanked for their assistance in data acquisition. This work was partially funded by an Adolf Martens Postdoctoral Fellowship from BAM (to J.N.H.).
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