PBT-based nanocomposites by in situ entropically-driven ring-opening polymerization of macrocyclic oligomers.

Pristine montmorillonite (MMT) modified with a new synthesized imidazolium salt bearing a functional moiety able to catalyze transesterification reactions was prepared and characterized. This modified MMT was used for obtaining PBT-based nanocomposites through in situ entropically-driven ring-opening polymerization (ED-ROP) of the corresponding macrocyclic oligomers (PBT-MCOs) previously intercalated in between the layers of the clay. TGA analysis of the imidazolium-modified clay indicates enhanced decomposition temperatures with respect to those of organoclay modified with ammonium salts. PBT-based nanocomposites with 3 wt% of pristine and imidazolium-modified MMT were prepared. WAXD results indicate the intercalation in between clay layers of PBT-MCOs before and of PBT polymer chains after ED-ROP.