Ionic liquids: A new way for the compatibilization of thermoplastic blends

•Ionic liquids: new compatibilizers of thermoplastic blends.•Compatibilizing effect of phosphonium ionic liquids.•Improvement of thermal and mechanical properties of PP/PA6 blends.

Ionic liquids based on tetraalkylphosphonium salts combined with different anions (phosphinate versus trifluoromethylsulfonylimide) have been used as new compatibilizers of polymer blends. To highlight the effect of thermostable ionic liquids, a very low amount of ILs (1–10 wt%) have been introduced within a PP/PA blend (80/20) and the polymer blends have been processed in melt by twin-screw extrusion. Transmission electron microscopy (TEM) analysis has been used to investigate the influence of ILs on the different morphologies of these binary blends. In addition to having improved thermal stability, an excellent stiffness–toughness compromise has been obtained (+1400%).