Synthesis and characterisation of novel PBT and PCCD telechelic ionomers prepared by end capping

Poly(butylene terephthalate) (PBT) and poly(1,4-cyclohexylenedimethylene 1,4-cyclohexanedicarboxylate) (PCCD) ionomers containing terminal ionic units, derived from a novel sodiosulfonate epoxy molecule, were synthesised using an end capping technique in solution. The sulfonated epoxide has the fundamental feature of selectively reacting with the polymer carboxylic terminal groups and therefore, creating polymers with terminal ionic groups. The presence of the sodiosulfonate end groups was confirmed by 1H NMR spectroscopy and titration of carboxyl end groups. Differential scanning calorimetry (DSC) indicated that the presence of ionic end groups has a different effect on the crystallisation process. In particular in PBT the ionic groups cause an increment of the crystallisation rate, whereas, in PCCD the opposite effect is observed.