Copolymerization of styrene with butadiene using methyl tert ‐butyl ether as active center modifier

Abstract

The copolymerization reaction of styrene with butadiene was performed using n‐butyllithium (BuLi) as initiator and methyl tert‐butyl ether (MTBE) as active center modifier. The randomness of the copolymers increases with decreasing polymerization temperature and increasing [MTBE]/[BuLi] molar ratio. The solvent and the modifier/initiator ratio strongly influence the copolymerization rate. In comparison with other modifiers, MTBE exhibits a moderate action on rate and selectivity of styrene‐butadiene copolymerization. The reaction rate increases as the [MTBE]/[BuLi] molar ratio increases from 7 to 40. At higher [MTBE]/[BuLi] molar ratios, the copolymerization rate decreases. First partial reaction orders with respect to styrene and butadiene were calculated. No transfer reactions were detected in cyclohexane, but these are evident in toluene. The microstructure of the butadiene units incorporated into the copolymer chain is little influenced by the polymerization temperature. Higher [MTBE]/[BuLi] molar ratios will lead to an increase in the number of butadiene units incorporated as vinyl units.

Conducting Block Copolymer Nanowires Containing Regioregular Poly(3‐Hexylthiophene) and Polystyrene

“…Titration of the Grignard reagents was performed following the procedure described by Love (19). Styrene was purified according to a procedure described elsewhere (20). Cyclohexane was distilled from sodium potassium alloy.…”

Hyperbranched and Hyperstar Polybutadienes via Anionic Self-Condensing Vinyl Copolymerization

“…This is due to the highly divergent monomer reactivity ratios ( r B ≈ 20, r S ≈ 0.05). , In polar, coordinating solvents like THF the situation is inverse ( r B ≈ 0.2, r S ≈ 8) . To achieve random copolymerization, Lewis bases (so-called randomizers) such as N , N , N ′, N ′-tetramethylethylenediamine (TMEDA), triethylamine (TEA), tetrahydrofuran (THF), and tert -butylmethylether (TBME) − have been used. These Lewis bases form adducts with the lithium cation, partially decreasing the aggregation of the lithiated chain ends. , …”

“…Therefore we have selected a Lewis base as a modifier for polymerization and both modifier concentration and temperature were studied. Styrene-butadiene copolymers showed a random distribution of comonomer units in the polymer chain at TBME/Li ratios above 20. , Thus, in our experiments we used TBME as a weak Lewis base in toluene.…”

“…Styrene-butadiene copolymers showed a random distribution of comonomer units in the polymer chain at TBME/Li ratios above 20. 45,46 Thus, in our experiments we used TBME as a weak Lewis base in toluene.…”

One-step Synthesis of Fully Biobased Two-Sided Tapered ABA-type Thermoplastic Elastomers

“…Moreover, besides being an established compound in industry and organic synthesis, MTBE possesses the potential for sustainable production from biobased methanol and biobased isobutane . As MTBE has been rarely used in carbanionic polymerization, its impact on copolymerization on Far and Nopa is investigated in the first section. ,,− …”