Method to isolate and characterize oligomers present in the aqueous phase in emulsion copolymerization

In order to model the entry of radical in emulsion copolymerization, a study of the oligomers present in the aqueous phase is necessary. In this work a new method for separation and characterization of the aqueous phase has been developed. MALDI-ToF-MS was found to be a powerful technique in order to characterize the oligomers present in the aqueous phase. It is for the first time that full chemical composition and molecular weight information of the oligomers present in the aqueous phase in emulsion copolymerization has been obtained. The methodology was shown to be semi-quantitative and several factors were studied, for example temperature effects, interference of latex particles present in serum of the aqueous phase and type of ionizing salt in MALDI. It was shown that the methodology works well, even though we are dealing with small quantities of oligomers and the possibility of mass discrimination in MALDI-ToF-MS.

A new characterization procedure has been developed to characterize aqueous phase oligomers in emulsion copolymerizations. These oligomers play a crucial role in entry of radicals into the latex particles but also control the surface characteristics of the latex particles and the aqueous phase characteristics.Figure optionsDownload as PowerPoint slideHighlights
► In this work a new method for separation and characterization of the aqueous phase has been developed.
► MALDI-ToF-MS was found to be a powerful technique in order to characterize the oligomers present in the aqueous phase.
► Full chemical composition and molecular weight information of the oligomers present in the aqueous phase was obtained.
► Even though we are dealing with very small quantities of oligomers the method works well.
► With the obtained information inference can be made on the critical chain length of entry in emulsion copolymerizations.