Synthesis and characterization of miktoarm star copolymer of styrene and butadiene using multifunctional macromolecular initiator

A new kind of multifunctional macromolecular initiator with Sn–C bonds and polydiene arms was synthesized by living anionic polymerization. At first, polydiene–stannum chloride (PD–SnCl3) was prepared by the reaction of n-butyl-Li (n-BuLi), stannic chloride (SnCl4) and diene. Then PD–SnCl3 was used to react with the dilithium initiator to prepare the multifunctional organic macromolecular initiators. The result suggested that the initiators had a remarkable yield by GPC, nearly 90%. By using these multifunctional macromolecular initiators, styrene and butadiene were effectively polymerized via anionic polymerization, which gave birth to novel miktoarm star copolymers. The relative molecular weight and polydispersity index, microstructure contents, copolymerization components, glass transition temperature (Tg) and morphology of the miktoarm star copolymers were investigated by GPC–UV, 1H NMR, DSC and TEM, respectively.