Following the morphological and thermal properties of PLA/PEO blends containing carbon nanotubes (CNTs) during hydrolytic degradation

In this article, the morphology, melting behavior, crystallinity and thermal stability of poly (lactic acid) (PLA)/poly (ethylene oxide) (PEO) blends and PLA/PEO/carbon nanotubes (CNTs) nanocomposites are studied before and after the hydrolytic degradation in neutral phosphate-buffered saline (PBS) solution. The morphologies of all the samples show PEO droplets in a continuous PLA phase, but the addition of CNTs to the blends diminishes the size of the PEO particles and homogenizes their dispersion before and after degradation. Additionally, the degradation did not change the morphologies of the samples. The samples showed two different melting peaks, indicating that the PLA/PEO blend is not miscible. The low crystallinity of PLA in the degraded samples was due to the short chains and high cold crystallization. The thermal decomposition of the samples occurred in two stages, demonstrating the poorer thermal stability of PLA compared to PEO. The positive and negative roles of CNTs in the thermal stability depend on the concentrations of PLA and CNTs, which determine the protective role or heat transfer of CNTs in the samples.