Influence of water absorption on the interlaminar behavior of carbon fiber-reinforced composites containing halloysite nanotubes

Polymer matrix composites deteriorate during prolonged exposure to water, especially at the fiber-matrix interface. Herein, water absorption and interfacial mechanical property degradation were evaluated after the addition of halloysite nanotubes (HNTs), which are inexpensive tube-shaped nanofillers. The water absorption ratio of the composite containing HNTs was lower than that of the reference. The mechanical properties, including flexural strength and interlaminar shear strength, were also less degraded in the composite containing HNTs. This improvement was attributed to the HNT nanofiller reinforcing the matrix and bridging propagating cracks. Concurrently, the HNTs acted as a water absorbent and water barrier, thereby preventing damage to the fiber-matrix interface by water. Halloysite nanotubes are suitable as a filler for applications exposed to high humidity or aqueous environments.