Characterization of functionalized styrene–butadiene rubber by flow field-flow fractionation/light scattering in organic solvent

Flow field-flow fractionation (FlFFF) using an organic solvent as mobile phase has been effectively utilized for the separation and characterization of functionalized styrene–butadiene rubbers (SBR) that are polymerized and followed by coupling reaction in solution. Separation of broad molecular weight SBR was accomplished by an asymmetrical FlFFF channel in THF under field programming and the molecular weight distribution (MWD) of the SBR sample was determined by on-line measurement of light scattering. In this study, FlFFF has been utilized to characterize high-MW functionalized SBR from the low-MW non-functionalized molecules which were used for coupling reaction to produce high-MW functionalized SBRs, and to determine the coupling number of the functionalized SBRs depending on the type of the coupling reagents. The resulting MWD of the SBR samples prepared by the different coupling reagents (SnCl4 and a polydimethylsiloxane compound) were compared.