The effective reinforcements of functionalized MoS2 nanosheets in polymer hybrid composites by sol-gel technique

In this work, siloxane group was grafted on the surface of exfoliated MoS2 nanosheets by chemical conjugation with 3-mercaptopropyl trimethoxysilane and then the functionalized MoS2 was incorporated into poly(vinyl alcohol) (PVA) matrix as reinforcements using sol-gel technique. The results of FTIR, TGA, XPS and TEM indicated that 3-mercaptopropyl trimethoxysilane was successfully grafted onto the surface of exfoliated MoS2 nanosheets. The functionalized MoS2 was well dispersed in PVA and no obvious aggregation of MoS2 nanosheets was observed. The incorporation of functionalized MoS2 nanosheets significantly enhanced the thermal properties, flame retardancy and mechanical properties of PVA films. The half weight loss degradation temperature of PVA films was increased from 298 to 416 °C and a 12 °C increment in the glass transition temperature was achieved with only 1.0 wt% functionalized MoS2. Furthermore, the peak heat release rate and the tensile strength of PVA films was decreased by 52.5% and improved by 98.4%, respectively, compared to that of neat PVA. These excellent reinforcements were mainly attributed to well dispersion of MoS2 nanosheets in the polymer matrix and strong interfacial adhesion between the two components. This work demonstrated herein will provide a promising route to fabricate MoS2-based polymer nanocomposites with excellent performances.