Monomer sequence determination in the living anionic copolymerization of styrene and asymmetric bi-functionalized 1,1-diphenylethylene derivatives

Abstract

In-chain functionalized polystyrenes with different sequential arrangements of functional groups are preparedvialiving anionic copolymerization. The sequence structures are determined by time sampling to establish the sequence-determination method.

Investigation of the Locked‐Unlocked Mechanism in Living Anionic Polymerization Realized with 1‐(Tri‐isopropoxymethylsilylphenyl)‐1‐phenylethylene

“…[12] Because of the quantitative incorporation of the monomer and heterogeneity during copolymerization, sequence-controlled polymers have been synthesized with av ariety of DPE derivatives. [14] When they possess lone-pair electrons,h eteroatoms can serve as ligands for metal-centered catalysts. [14] When they possess lone-pair electrons,h eteroatoms can serve as ligands for metal-centered catalysts.…”

“…[12,13] Additionally,heteroatoms (such as Nand O) can be successfully incorporated into DPE units,and copolymerization can be conducted without side reactions. [14] When they possess lone-pair electrons,h eteroatoms can serve as ligands for metal-centered catalysts. [10,15] In LAP,p olar heteroatomcontaining additives,s uch as tetrahydrofuran (THF) or N,N,N',N'-tetramethylethylenediamine (TMEDA), have been shown to have as ignificant impact on the kinetics of the reaction and the resulting microstructures.…”

Investigation of the Locked‐Unlocked Mechanism in Living Anionic Polymerization Realized with 1‐(Tri‐isopropoxymethylsilylphenyl)‐1‐phenylethylene

“…The details of the syntheses are presented in Figure a, and the main discovery made during copolymerization was that when only sodium 2,3‐dimethylpentan‐3‐olate (NaODP) was used as an additive, the copolymerization reaction generated polymers, while the use of other additives (i.e., conditions using TMEDA, THF or NEAT) generated living anions (dark‐red color that persisted until termination) but no product. This finding was different from what we observed in our copolymerization with DPE derivatives containing heteroatoms, such as DPE‐NMe 2 , DPE‐(NMe 2 ) 2 , DPE‐SiH/OMe, and DPE‐SiOEt . Even though side reactions occurred when DPE‐SiOEt, which possesses one alkoxysilyl group, was used, the copolymerization still provided the desired polymers.…”

Sequence Determination and Regulation in the Living Anionic Copolymerization of Styrene and 1,1‐Diphenylethylene (DPE) Derivatives

“…New derivatives such as DPE‐SiH/OMe and DPE‐SiH/NMe 2 were synthesized and copolymerized with St. The detailed process of the sequence determination is described in ref ,. and the results are shown in Scheme .…”

“…These effects can be clearly confirmed by the change of the reactivity ratios (r St ). For DPE‐SiH, its theoretical r St was calculated by the Hammett equation as 0.38, and the r St changed to 1.17 and 1.29 when electron‐donating groups (–OMe and –NMe 2 ) were introduced into DPE‐SiH structure. This variation affirmed that the sequential distribution of DPE units could be regulated through the regulation of its substituent structures.…”