Mussel-inspired decoration of Ni(OH)2 nanosheets on 2D MoS2 towards enhancing thermal and flame retardancy properties of poly(lactic acid)

In the present work, a facile and environmental method was developed to fabricate the novel functionalized MoS 2 hybrid. Firstly, MoS 2 nanosheets were coated with polydopamine (PDA) through the self-polymerization of dopamine (MoS 2 -PDA) in a buffer solution. Then the decoration of Ni(OH) 2 on the MoS 2 -PDA was synthesized because of the strong affinity of Ni 2+ with hydroxyl groups in PDA. Finally, the as-synthesized MoS 2 -PDA@Ni(OH) 2 was introduced into poly(lactic acid) (PLA) matrix to explore flame retardancy, thermal stability, and crystalline property of the composites. As confirmed by X-ray diffraction (XRD), Fourier-transform infrared spectrometer (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA), the MoS 2 nanosheets were dually modified with PDA and Ni(OH) 2 without destroying the original structures. The thermal degradation of PLA with MoS 2 -PDA@Ni(OH) 2 generated a notably higher yield of char. Moreover, the crystallization rate of composites is higher than neat PLA. The cone calorimeter test revealed that the introduction of 3% MoS 2 -PDA@Ni(OH) 2 resulted in lower Peak Heat Release Rate (PHRR) (decreased by 21.7%). Thus, the research provided an innovative functionalization method for manufacturing PLA composites with high performances.