Browsing by Author "Maku, Lebogang Jennifer"
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- ItemIdentification and characterization of additives in colourants by advanced analytical techniques(Stellenbosch : Stellenbosch University, 2015-12) Maku, Lebogang Jennifer; Pasch, Harald; Stellenbosch University. Faculty of Science. Dept. of Chemistry and Polymer Science.ENGLISH ABSTRACT: Various types of anionic, non-ionic, cationic and zwitterionic additives are used in the coatings industry for the production of paints and colourants. These additives are added to enhance properties such as stabilization of pigment dispersions, wetting of pigments and improvement of open time and freeze/thaw stability. Very often the exact chemistry of these commercial additives is unknown and this is a limitation for new product developments. The identification and characterization of these multi-component polymeric materials continues to be a challenging task. This research presents the use of various advanced analytical techniques to identify and characterize commercial additives that are used in a multi-component colourant formulation. The focus of the present study is on additives that are based on poly(ethylene glycol) (PEG). The molar mass distribution of PEG-based additives was determined with liquid chromatography coupled to mass spectrometry (LC-MS) using solvent gradient elution and at critical conditions of adsorption (LCCC) of PEG. Using the combination of LC-MS, proton nuclear magnetic resonance spectroscopy (1H NMR), pyrolysis gas chromatography (py-GC-MS) and Fourier transform infrared spectroscopy in attenuated total reflectance mode (FTIR-ATR), different additives were identified in terms of the number and type of polymer end groups. The efficiency of the extraction and identification protocol was demonstrated for a blend of additives in a colourant formulation.