Butadiene Polymerization Catalyzed by Tri(aryloxo)aluminum Adduct of Cobalt Acetate

Bulletin of the Korean chemical society

Ji Hae Park¹  Ka Hyun Park¹  Ahreum Kim¹  Bun Yeoul Lee¹  Gwanghoon Kwag¹  Junseong Lee¹  Sung Hae Jun¹ 

关键词: Butadiene polymerization;    trans-1;    4-Polybutadiene;    Cobalt complexes;    Phenoxoaluminum complexes;   

DOI  :  

学科分类：化学（综合）

来源: Korean Chemical Society

【 摘 要 】

Tris(2-phenylphenoxo)aluminum ((2-PhC6H4O)3Al) exists as a dimeric form in toluene. When toluene-insoluble anhydrous cobalt acetate is treated with tris(2-phenylphenoxo)aluminum in toluene, the toluene-soluble adduct (2-PhC6H4O)3Al·Co(OAc)2 is formed. The 2-phenylphenoxo ligand in the adduct can be replaced with another aryloxo ligand to give (aryloxo)(2-PhC6H4O)2Al·Co(OAc)2 (aryloxo = 2-methylphenoxo, 2-isopropylphenoxo, 4-methylphenoxo, 4-isopropylphenoxo, or 4-tert-butylphenoxo). These complexes are active for butadiene polymerization without gel formation when activated with an equivalent amount of (2-PhC6H4O)AlEt2 for 2 h. The highest activity, 175 kg/mol-Co (turnover number, 3200) was achieved with (2-PhC6H4O)3Al·Co(OAc)2 at 65 oC for 2 h. The microstructure of the polymer chains is mostly trans-1,4-configuration (70-75%) with the remaining being 1,2-vinyl. The cis-1,4-configuration observed by IR is minimal (1-5%). By replacing the 2- phenylpheoxo with a 4-alkylphenoxo ligand, the amount of 1,4-configuration slightly increases, resulting in increase in the endothermic melting signal at −30~50 oC in the DSC curve. The molecular weights of the polymers are high (Mn: 300000~800000) with a fairly narrow molecular weight distribution (Mw/Mn, 2.0-2.7).

【 授权许可】

Unknown