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(P-204)(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 degrees 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, H-1 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.