The Architecture of Hydroxy-Functionalized aPS-b-Random Copolymer-b-PE via One-Pot Strategy Combining Living Free Radical Polymerization with Coordination Polymerization

The copolymerization of styrene with ethylene was promoted by CpTiCl3/BDGE/Zn/MAO catalyst system combining free radical polymerization with coordination polymerization via sequential monomer addition strategy in one-pot. The effect of polymerization conditions such as temperature, time, ethylene pressure, and Al/Ti molar ratio on the polymerization performance was investigated. The hydroxy-functionalized aPS-b-random copolymer-b-PE triblock copolymer was obtained by solvent extraction and determined by GPC, DSC, WAXD, and C-13-NMR. The DSC result indicated that the aPS-b-random copolymer-b-PE had a T-g at 87 degrees C and a T-m at 119 degrees C which attributed to the T-g of aPS segment and the T-m of PE segment, respectively. The microstructure of the hydroxy-functionalized aPS-b-random copolymer-b-PE was further confirmed by WAXD, C-13-NMR, and H-1-NMR analysis; and these results demonstrated that the obtained block copolymer consisted of aPS segment, S-E random copolymer segment, and crystalline PE segment. The connection polymerization of the hydroxy-functionalized aPS with random copolymer-b-PE was revealed by GPC results. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 120: 3171-3179, 2011