A New Synthesis Strategy on Styrene-Butadiene Di-Block Copolymer Containing High cis-1,4 Unit Via Transfer of Anionic to Coordination Polymerization

Abstract

A novel synthesis strategy on styrene-butadiene di-block copolymer (PS-b-PB) with high cis-1,4 unit content was developed, based on a transfer technique from anionic to coordination polymerization. Firstly, the styrene monomer was initiated by n-butyllithium (Li) utilizing anionic polymerization at 50 °C, which resulted in a macromolecular alkylating initiator (PSLi). Secondly, PSLi was aged with nickel naphthenate (Ni) and boron trifluoride etherate (B) for obtaining a complex catalyst system (Ni/PSLi/B). Then, Ni/PSLi/B was applied to initiate the butadiene (Bd) polymerization. Following this new strategy, a series of PS-b-PBs were successfully synthesized. The experimental results indicated that under the molar ratio combination of [Li]/[Ni] = 5 and [B]/[Li] = 1, styrene-butadiene di-block copolymers could be easily achieved with high cis-1,4 unit content (>97%) and controlled molecular weight as well as narrow molecular weight distribution (Mw/Mn < 1.5). Furthermore, the copolymer’s block ratio could also be effectively controlled by controlling the two components’ monomer feed ratio.

Effects of Structurally Different Tertiary Amines on the Properties of Quaternized Anionic Exchange Membranes Potentially Applicable for Water Electrolysis

“…All the spectra were normalized with respect to trans 1,4-butadiene absorption at 966 cm −1 . [34,35]…”

Synthesis of block copolymer with cis -1,4-polybutadiene and isotactic-rich polystyrene using α-diimine nickel catalysts

“…In ternary rare earth-catalysed coordination polymerization, neodymium carboxylate and neodymium phosphonate are usually used as the main catalysts [ 14 , 15 ], and high cis -1,4-selectivity (greater than 96%) can be obtained. However, the styrene block in the resulting copolymers generally exhibit atactic sequences, and the monomer conversion rate is very low [ 13 , 16 ].…”

Scandium-catalyzed stereoselective block and alternating copolymerization of diphenylphosphinostyrenes and isoprene

“…In the past decades, enormous efforts have been devoted to the copolymerization of styrene with dienes, affording a considerable number of styrene–diene copolymers with diverse structures. 1–16 Moreover, the copolymerization of polar styrenes with dienes has been successfully achieved by free radical polymerization 17 and living anionic polymerization. 18–20 Although coordination polymerization is favourable to adjust the regio- and stereoselectivity of copolymerization, 21 the active species are prone to be poisoned by polar groups in many cases.…”