Effect of nanoclay (Cloisite 30B) and antioxidant (Irganox 1010) on the physico- and thermo-mechanical properties of thermoplastic polyurethane prepared via a semi-continuous method in an internal mixer

This study reports the design and preparation of thermoplastic polyurethane (TPU), TPU/Cloisite 30B (0.4, 0.8, and 1.2 wt %) nanocomposites, and TPU/Irganox 1010 (0.5, 1, and 1.5 wt%) through a semi-batch method in an internal mixer and glass reactor. For this purpose, poly (ethylene adipate) was reacted with 4,4’-methylene diphenyl isocyanate to obtain the prepolymer and subsequently cured with 1,4-butanediol (BD) as chain extender to obtain the TPU sample. To accurately evaluate the curing reaction time (6 min), samples were taken from the internal mixer at specified intervals and then subjected to ATR-FTIR analysis (at 2, 4, and 6 min). Good distribution and dispersion of nanoclays in the resulting TPU nanocomposites were confirmed by XRD and scanning electron microscopy. Thermogravimetric analysis showed that the T5% and T50% of the TPU nanocomposite (TPU/Cloisite 30B (1.2 wt%)) were 15 and 33 °C higher compared to TPU-Internal. Similarly, the tensile strength of the TPU nanocomposite (TPU/Cloisite 30B (1.2 wt%)) was improved by about 25% compared to TPU-Internal. DMTA analysis revealed that the tan δ was decreased due to steric hindrance of Irganox 1010 on TPU chain mobility. Additionally, the tanδ peak for TPU-Internal was shifted from − 5.35 °C to 7.10 °C and − 1 °C for TPU 6 and TPU 3, respectively.