The reaction of epoxy-telechelic polydimethylsiloxanes with polybutadienyllithium was used to prepare a series of low-molecular-weight polybutadiene-block-polydimethylsiloxane-block-polybutadiene copolymers. The copolymers were purified by repeated fractional precipitation/centrifugation and characterized with NMR, vapor pressure osmometry, size exclusion chromatography, and elemental analysis. The applicability of this method is discussed. (c) 2006 Wiley Periodicals, lnc.