Characteristics of Polyurethane Composites Containing Polyurethane Grafted Multi-walled Carbon Nanotubes

Thermoplastic polyurethane elastomer (TPU) and multi-walled carbon nanotubes (MWCNTs) fiinctionalized with isocyanate groups were melt mixed in a twin extruder to produce TPU composites containing TPU grafted MWCNTs (TPU-g-MWCNT) by reacting isocyanate groups on MWCNTs with the hydroxyl groups in TPU. Formation of TPU-g-MWCNTs by reactive extrusion was explored as were their resulting properties including interfacial adhesion energies between TPU and MWCNT and mechanical properties of TPU/MWCNT composites. The interfacial adhesion energy of the TPU/TPU-g-MWCNT composite was higher than that of the TPU/pristine MWCNT composite; a result, the TPU/TPU-g-MWCNT composite exhibited a higher level of dispersion of MWCNTs in the TPU matrix and better adhesion at the interface between TPU and MWCNTs than the TPU/pristine MWCNT composite. For a fixed MWCNT content in the composite, the mechanical strength of the TPU/TPU-g-MWCNT composite was higher than those of the corresponding TPU/pristine MWCNT composite.