Polymerization of n-Octylallene with Rare Earth Catalyst Composed of Ln(P204)3/Al(i-Bu)3

Polymerization of n‐octylallene was successfully carried out using a conventional binary rare earth catalytic system composed of rare earth tris(2‐ethylhexylphosphonate) (Ln(P₂₀₄)₃) and tri‐isobutyl aluminum (Al(i‐Bu)₃) for the first time. The effects of catalyst, solvent, reaction time and temperature on the polymerization of n‐octylallene were studied. The resulting poly(n‐octylallene) has weight‐average molecular weight of 11000, molecular weight distribution of 1.4 and 96% yield under the moderate reaction conditions: [Al]/[Y] =50 (molar ratio), [n‐octylallene]/[Y] =100 (molar ratio), polymerized at 80°C for 20 h in bulk. The poly(n‐octylallene) obtained consisted of 1,2‐ and 2,3‐polymerized units, and was characterized by FT‐IR, ¹H NMR and GPC. Further investigation shows that the polymerization of n‐octylallene has some living polymerization characteristics, preparing the polymer with controlled molecular weight and narrower molecular weight distribution.