Abstract: | This paper demonstrates that carbon nanotubes (CNTs) can be used as an effective filler for inhibiting the hydrolysis of polyurethane (PU) under acidic and basic conditions. Although it has been reported that CNTs can quench the radicals on its surface, for the first time, it is confirmed that CNTs undergo reactions that have an inhibiting effect on ion‐mediated hydrolysis. Attenuated total reflectance–infrared spectroscopy measurements on PU and PU–CNT samples reveal that CNTs inhibit the hydrolysis of PU in both acid and alkaline environments. Via quantum chemical calculations, it is shown that CNTs can trap H+ ions and OH? ions on their surface. It is also shown that CNTs can trap multiple ions, even though electrical repulsion is to be expected. The results reveal that CNTs can also function as a hydrolysis inhibitor in addition to their known functions as an antioxidant. |