Nanocomposites of halloysite and polylactide

Naturally occurred halloysite (Hal) nanotubes compounded with polylactide (PLA) via melt mixing formed biodegradable and biocompatible clay polymer nanocomposites (CPN). The hydrogen bonding interactions between Hal and PLA were confirmed by Fourier transform infrared spectroscopy (FTIR). The modulus, strength and toughness of the Hal-PLA nanocomposites were substantially higher than those of neat PLA. Storage modulus and glass transition temperature of the Hal-PLA nanocomposites also increased with Hal loading as observed by dynamic mechanical analysis. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) results showed that Hal was uniformly dispersed and oriented in the CPN. X-ray diffraction (XRD) of the CPN showed the absence of Hal reflection at around 20°, indicating interactions of the PLA molecular chains in the interlayer space of Hal. Hal could nucleate PLA, leading to the decreased cold crystallization temperature and increased crystallinity. The vicat softening temperature and the degradation temperature of the CPN increased with Hal loading. Owing to the high performance and biocompatibility of the CPN, the prepared Hal-PLA nanocomposites had potential applications in biodegradable plastic and biomedical areas.