the synthesis of poly by living carbocationic polymerization employing the sequential monomer addition technique is described . the process starts by producing the living pib ⊕ block employing the 2 - chloro - 2 , 4 , 4 - trimethylpentane in ch 3 cl / n - c 6 h 14 or ch 2 cl 2 / n - c 6 h 14 mixed solvents at - 80 ° c . and continues by the addition of methyl vinyl ether . the second living block forms only in the presence of excess ticl 4 suggesting that the species that starts the second block and subsequently sustains its growth is a meve · ticl 4 complex . the stoichiometry of this complex is uncertain . the ticl 4 remains attached to the meve units after their incorporation into the diblock , however , it can be readily removed by water . pmeve obtained in the presence of excess ticl 4 degrades by dealcoholation , however , degradation is prevented by the use of n - bu 4 ncl . various length diblocks have been prepared and characterized . the novel pib - b - pmeve &# 39 ; s exhibit strongly amphiphilic character .