Application of two-dimensional MoS2 nanosheets in the property improvement of polyimide matrix: Mechanical and thermal aspects

Two dimensional (2D) MoS2 nanosheets are firstly exfoliated by high shear mixing technique and then incorporated into PAA precursors to form the MoS2/PI nanocomposite films, and the preparation can be accomplished via in-situ polymerization, tape casting and thermal imidization processes. As a result, the mechanical and thermal properties of the prepared MoS2/PI nanocomposite films are significantly enhanced by incorporation of a small amount of MoS2 nanosheets without any surface modification. Especially, 43% and 47% increases in tensile strength and Young's modulus can be respectively achieved upon adding certain small amount of MoS2 (0.75 wt% or so). Meanwhile, the glass transition temperature (Tg) can be effectively improved by 11 °C by taking advantages of unique superior thermal stability of MoS2 nanosheets. This desirable fabrication of MoS2/PI nanocomposite films is expected to offer a new avenue on the development of high strength PI-based nanocomposites with comprehensive performances.