Polymerization of 1,3-Butadiene with NiCl2 in Combination with Methylaluminoxane

Abstract

Experimental MaterialsCommercial available Bd was purified by distillation over calcium hydride before use. NiCl 2 was used as an anhydrate prepared by a dehydration of NiCl 2 · 6H 2 O (Wako Chem. Co.) at 140°C under high vacuum. PMAO diluted with toluene kindly supplied from Tosoh-Fine Chem. Co. was used as received. Solvents and other reagents were used after purification by conventional methods. After the reaction of NiCl 2 with MAO at 25°C for 0.5 h, 5.0 Å pore filter (Milipore Co.) was used to separate them into the soluble and the insoluble fraction. Average particle size of 25 mm, 500 mm and 1 mm of NiCl 2 was used. Unless refer to the particle size 500 mm particle size was used. Polymerization of 1,3-Butadiene with NiCl 2 in Combination with MethylaluminoxaneKiyoshi ENDO* and Yoshihiro YAMANAKA Abstract The polymerization of 1,3-butadiene (Bd) with NiCl 2 /methylaluminoxane (MAO) catalyst was investigated. The reaction mixture of NiCl 2 and MAO was separated into soluble and insoluble part. Both parts initiated the polymerization of Bd to give a high cis-1, . The activity for the polymerization of the soluble part was higher than that of the insoluble part. The M w /M n of the polymer obtained with the soluble part was around 2.0, but that obtained with the insoluble part was 4.5. The polymerization of Bd with NiCl 2 in combination with MAO depended on a particle size, i.e., surface area of NiCl 2 , and the activity for the polymerization with a small particle size of NiCl 2 was higher than that with a large particle.

Effect of an alkyl substituted in salen ligands on 1,4‐Cis selectivity and molecular weight control in the polymerization of 1,3‐butadiene with (salen)Co(II) complexes in combination with methylaluminoxane

“…Because the polymerization of Bd with the (salen) Co(II) complexes bearing t-butyl at the 3,3 0 ,5,5 0positions of the ligand was higher than that with the (salen)Co(II) complex without substitution, 14 we investigated the effect of the bulkiness of alkyl substituents at the 3,3 0 ,5,5 0 -positions of the (salen) Co(II) complexes (1-3) on the polymerization of Bd. The results are listed in Table 1 (runs 1-5).…”

“…We reported that the polymerization of Bd with the (salen)Co(II)/MAO catalysts was influenced by the introduction of the t-C 4 H 9 group at the 3,3 0 ,5,5 0 -positions on the aromatic ring of the salen ligand. 14 The bulkiness of the substituents at the 3-and 5-positions in the aromatic ring of the (salen)Co(II) complexes may influence the activity for both the polymerization of Bd and the microstructure of the polymer. However, such effects have not been investigated.…”