Cationic polymerization of 1,3-pentadiene and 2-methylpropene: Direct initiation is a general mechanism with AlCl3 in polar medium

Following previous results showing that direct initiation was operating in the cationic polymerization of 1,3-pentadiene in the presence of AlCl3 in non-polar medium, it is shown on the same system that direct initiation also occurs in polar medium. In the case of 2-methylpropene the use of a proton trap (DtBP) allowed to show that at −30 °C, direct initiation mechanism was operating either in 64/36 or in 36/64 (v/v) CH2Cl2/pentane mixtures. These results show that direct initiation is a general mechanism with AlCl3. SEC studies showed that for 2-methylpropene transfer can be minimized.