A novel synthetic strategy for styrene-butadiene-styrene tri-block copolymer with high cis-1,4 units via changing catalytic active centres.

ABSTRACT: A styrene-butadiene-styrene tri-block copolymer (SBS) with a high cis-1,4 unit content (greater than 97%) was synthesized by a novel synthetic strategy based on changing the catalytic active centres using n-butyllithium and a nickel-based catalyst. Firstly, styrene was polymerized via anionic polymerization using butyllithium as the initiator (Li, activity centre Li) at 50°C. The obtained alkylated macroinitiator (PSLi) was aged with nickel naphthenate (Ni) and boron trifluoride etherate (B) to prepare a second reactive centre (Ni-F), which was used to initiate the polymerization of butadiene (Bd). Finally, triphenyl phosphine (PPh₃) was added to adjust the electron density of the third active centre (P-Ni-F), and styrene monomer was added again to synthesize the s

SUBMITTER: Liu J 

PROVIDER: S-EPMC6599772 | biostudies-literature | 2019 Jun

REPOSITORIES: biostudies-literature