Zhang Haiyan（Key Laboratory on Preparation and Processing of Novel Polymer Materials,Beijing University of Chemical Technology, Beijing 100029, China）　 Zhang Xingying（Key Laboratory on Preparation and Processing of Novel Polymer Materials,Beijing University of Chemical Technology, Beijing 100029, China）　

Abstract：As is well known, in the anionic polymerization the apparatus and reagents are purified and all reactions are conducted in nitrogen atmosphere. The synthesis of the macromolecular multifunctional initiator and the miktoarm star styrene-isoprene-butadiene copolymer[PD-Sn-(SBR)3] were performed according to the following 4 basic reactions: (1) The diene [isoprene(Ip) or butadiene(Bd)] was initiated by the n-BuLi(simplified as Li) in the cyclohexane, at 50 ℃ for 4 h (the obtained product was noted as PDLi). (2) The living arm PILi (or PBLi) (polyisoprene and polybutadiene noted as PI and PB) was added drop wise to the reactor containing SnCl4 in cyclohexane under vigorous stirring. (3) The macromolecular multifunctional initiator [PD-Sn-(Li)3] was produced by gradually dropping the product PD-SnCl3 into the dilithium initiator. (4) Styrene(St), Bd and tetrahydrofuran (THF) was premixed and added into the reactor and then the polymerization was initiated by the macromolecular multifunctional initiator [PD-Sn-(Li)3]. The reaction was conducted at 50 ℃ for 5 h, and the mole ratio of THF to Li was 50 .