Living copolymerization of ethylene and 1-octene was carried out at room temperature using the fluorinated FI-Ti catalyst system, bis[N-(3-methylsalicylidene)-2,3,4,5,6-pentafluoroanilinato] TiCl2/dried methylaluminoxane, with various 1-octene concentrations. The comonomer incorporation up to 32.7 mol % was achieved at the 1-octene feeding ratio of 0.953. The living feature still retained at such a high comonomer level. The copolymer composition drifting was minor in this living copolymerization system despite of a batch process. It was found that the polymerization heterogeneity had a severe effect on the copolymerization kinetics, with the apparent reactivity ratios in slurry significantly different from those in solution. The reactivity ratios were nearly independent of polymerization temperature in the range of 035 degrees C. (c) 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013