Details

Autor(en) / Beteiligte

• Gong, Dirong
• Dong, Weimin
• Hu, Yanming
• Bi, Jifu
• Zhang, Xuequan
• Jiang, Liansheng

Titel

Syndiotactically enriched 1,2-selective polymerization of 1,3-butadiene initiated by iron catalysts based on a new class of donors

Ist Teil von

• Polymer (Guilford), 2009-11, Vol.50 (25), p.5980-5986

Ort / Verlag

Kidlington: Elsevier Ltd

Erscheinungsjahr

2009

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• A series of phosphoryl (P O) contained compounds: triethylphosphate ( a), diethylphenylphosphate ( b), ethyldiphenylphosphate ( c) triarylphosphates ( d and h– m), triphenylphosphine oxide ( e), phenyl diphenylphosphinate ( f) and diphenyl phenylphosphonate ( g) have been prepared. Iron catalysts, which are generated in situ by mixing the compounds with Fe(2-EHA) 3 and Al iBu 3 in hexane, are tested for butadiene polymerization at 50 °C. Phosphates donated catalysts have been, unprecedently, found to conduct extremely high syndiotactically (pentad, rrrr = 46.1–94.5%) enriched 1,2-selective (1,2-structure content = 56.2–94.3%) polymerization of butadiene. Introduction of electron withdrawing substituents on phenyl rings oftriphenylphosphate ( k– m) remarkably promotes catalytic activity, while bulky substituent isopropyl at 2-position ( h) has beneficial influence on regioselectivity. Employment of e, f or g as donor, results in a suppressed monomer conversion, accompanied by deteriorated 1,2-regioselectivity. The effects of polymerization conditions such as reaction temperature, types of cocatalysts and polymerization medium are also investigated by using catalyst system with tri(2,4-difluorophenyl)phosphate ( m) as donor. Highly tolerance to polymerization temperature up to 80 °C is observed for the first time in the iron-based catalyst. [Display omitted]