Synthesis of polyolefin‐block‐polystyrene through sequential coordination and anionic polymerizations

Abstract

ABSTRACTTwo representative bulk polymers, polyolefin (PO) and polystyrene (PS), were molecularly connected to form PO‐block‐PS by sequentially performing coordination and anionic polymerizations in one pot. Ethylene/1‐octene copolymerization was performed using a typical ansa‐metallocene catalyst, rac‐[Me2Si(2‐methylindenyl)]2ZrCl2, in the presence of (benzyl)2zinc to grow PO‐chains at the Zn site. Anionic styrene polymerization was subsequently performed using nBuLi·(tmeda) (tmeda, N,N,N′,N′‐tetramethylethylenediamine) initiator to consecutively grow PS‐chains at the Zn site. The composition and the molecular weight of the PO‐blocks were controllable depending on the feed amounts of 1‐octene and (benzyl)2zinc (1‐octene fraction: ∼20, ∼40 wt %; PO‐Mw, 77,000–174,000) and the PS‐block size was also controlled (PS‐Mn, ∼21,000) with the complete conversion of the styrene monomer. Formation of block copolymers was evident in the GPC curves, TEM images, and strain‐stress curves. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 3110–3118