Copolymerization of butadiene (Bd) and styrene (St) were carried out by using a rare earth catalyst system. The microstructure, composition, and morphology of the copolymer were characterized by FTIR, 1H-NMR, 13 C-NMR and TEM. The molecular weight, molecular weight distribution and the composition distribution of the copolymer were determined by GPC with RI and UV detectors. The results show that the copolymer is a block copolymer of butadiene and styrene with high cis-1,4 content. The cis-1,...