Poly (butylene terephthalate) ionomers with imidazolium groups selectively located as end- groups (telechelic) have been prepared by melt polycondensation adding a hydroxyl derivatized imidazolium salt at the beginning of the polymerization process. The design of the chemical structure of the imidazolium salt is of fundamental importance in order to achieve the synthesis of ionomers with good thermo-mechanical properties. The final ...