The effect of silicon dioxide nanoparticle-covered graphene oxide on mechanical properties, thermal stability and rheological performance of thermoplastic polyurethanes

A two-step grafting procedure has been used to graft tetraethylenepentamine (TEPA) and nano silicon dioxide (SiO2), onto graphene oxide (GO) surface. The resulting modified GO, that was TGOS, which was used as a reinforcement in thermoplastic polyurethanes (TPUs). Mechanical properties, thermal stability and rheological properties of composites were investigated. Results showed that the addition of TGOS significantly improved the mechanical properties of TPU compared with the pure TPU sample. Tensile strength and elongation at break of TPU were increased by 50.8 and 18.6%, respectively, when the addition amount was only 0.5 wt%. TG results showed that the addition of TGOS improved the heat resistance of TPU. Complex viscosity, storage modulus (G') and loss modulus (G) of TPU composites with different additions were analyzed by rheological tests, the results showed that the addition of TGOS improved the deformation resistance of TPU. Meanwhile, TPU composites present high G', G, and complex viscosity with the increase of TGOS filling amount in the low frequency region.

Automated summary

A two-step grafting procedure was used to graft TEPA and SiO2 onto GO surface to obtain TGOS for reinforcing TPU, resulting in significant improvements in mechanical properties and heat resistance. Rheological tests showed that the addition of TGOS improved the deformation resistance of TPU.