Synthesis of polymers containing pseudohalide groups by cationic polymerization, 13 . “Living” polymerization of 2‐methylpropene initiated by the system 1,4‐bis(1‐azido‐1‐methylethyl)benzene/BCl 3 /dimethyl sulfoxide

Polymerizations of 2‐methylpropene (MP) initiated by the system 1,4‐bis(1‐azido‐1‐methylethyl)benzene (DAMEB)/BCl 3 in the presence of DMSO were carried out by “all monomer in” (AMI) technique at −70°C in CH 2 Cl 2 solution. FT‐IR, 1 H NMR and SEC analyses of polymers (PMP) showed that the M n versus weight of PMP plot is a straight line without intercept and azide F n3 and aromatic ring F ϕ functionalities are close to the theoretical values of 2 and 1, respectively. A polymerization of MP initiated by the system α,ω‐diazido‐PMP/BCl 3 /DMSO led to a final poly(2‐methylpropene) (PMP) with an increase of M n corresponding to the amount of MP introduced and presenting the same functionalities F N3 and F ϕ as the starting PMP. These results indicate that the polymerization system MP/DAMEB/BCl 3 /DMSO is a “living” one, because in an acceptably large range of molecular weight ( M n < 50000) the Mayo plot 1/ DP versus 1/ DP 0 is a straight line. The intercept gives k trM / k p = 4 · 10 −5 , showing the transfer reaction proceeds at very low rate.