Layered Double Hydroxide Nanoplatelets with Ultrahigh Specific Surface Area for Significantly Enhanced Crystallization Rate and Thermal Stability of Polypropylene

A facile method for the simultaneous delamination and the lateral size reduction of layered double hydroxides (LDH) is reported. This method directly resulted in the delaminated mesoporous LDH nanoplatelets (nanodot LDH) with the high specific surface area (lateral dimensions as low as 10-30 nm and featured a thickness of 1 nm). Such prepared LDH was used as fillers for isotactic polypropylene (iPP). For the purpose of comparison, LDH having different surface areas were also used as fillers for iPP. The incorporation of nanodot LDH showed a remarkable improvement in the polymer properties with only 1 wt % loading. The uniformly dispersed LDH particles have a significant effect on the nucleation ability, thermal stability, and mechanical properties of iPP. The nucleation ability of iPP in the presence of nanodot LDH is the best compared to other iPP nanocomposites reported using LDH as fillers in the literature. Furthermore, the microstructure of the iPP nanocomposites was systematically investigated at multiple length scales in the presence of different-sized LDH, which is a key to understand the polymer properties.