Preparation of isotactic polypropylene/exfoliated MoS₂ nanocomposites via in situ intercalative polymerization

In this research, a Ziegler-Natta catalyst intercalated MoS₂ was synthesized through the intercalation of a Grignard reagent into MoS₂ galleries, followed by the anchoring of TiCl₄. During propylene polymerization, the intercalated MoS₂ exfoliated in situ to form PP/exfoliated MoS₂ (EMoS₂) nanocomposites. The isotactic index values of the resultant PP/EMoS₂ nanocomposites were as high as 99%, varying from 98.1% to 99.0%. It was found that the incorporation of the EMoS₂ significantly improved the thermal stability and mechanical properties (tensile strength, modulus, and elongation at break) of PP. After introduction of EMoS₂, the maximum increases in Td5% and Tdmax were 36.9 and 9.7 °C, respectively, relative to neat PP. After blending with commercial PP, the resultant nanocomposites increase in tensile strength and modulus up to 11.4% and 61.2% after 0.52 wt % EMoS₂ loading. Thus, this work provides a new way to produce high-performance PP.