Polymer Bulletin, Vol.73, No.2, 509-518, 2016
Synthesis and characterization of random styrene-butadiene copolymer with Nd-based catalyst
Random styrene (St)-butadiene (Bd) copolymer (SBR) was obtained with the catalyst system composed of Nd(P-507)(3), methylaluminoxane (MAO) and indene. This Nd-based catalyst system showed high activity and selectivity toward the copolymerization. Indene was proven to be the critical component to achieve the high content of St units (similar to 33.0 %). Raising the polymerization temperature was beneficial to enhance the coordination of St to the active center, affording the increased yield and number-average molecular weight (M-n) of SBR. The polymers obtained in aliphatic solvents possessed higher M-n than M-n of SBR generated in toluene. The composition of SBR was controllable by adjusting the feed ratio of St/Bd. NMR and DSC analysis illustrated that the copolymers sustained random distribution even when St incorporation in SBR was up to 33.0 %. SBR was fully characterized by NMR, FTIR, GPC and DSC analysis.