Sustainable and Efficient Manufacturing of Metal-Organic Framework-Based Polymer Nanocomposites by Reactive Extrusion

Abstract

Over the past decades, metal–organic frameworks (MOFs) have been considered to be a promising category of materials for gas storage, separation, and catalysis. However, industrial commercialization of MOFs is restricted by their intrinsic operating conditions due to poor processability in powder shape. An integration of MOFs with a polymer matrix has been considered as an efficient way to improve the practical utility of powder MOFs. In contrast to the conventionally discrete bottom-up principle in milligram scale, in this work, a continuously rapid and solvent-free approach is developed to directly manufacture MOF–polymer nanocomposites from solid reagents (polymer matrix, metal irons, and ligands) via reactive extrusion, which can reach a space time yield as high as ∼1.2 × 105 kg/m3/day. To investigate the feasibility of this one-step reactive extrusion method, two types of widely used polymer matrixes, polypropylene and polystyrene, are chosen to manufacture different MOF-based nanocomposites using a Process 11 parallel twin-screw extruder. Specific MOFs, zeolitic imidazolate frameworks (ZIFs), namely, ZIF-8 and ZIF-67, are used herein. The improvements of thermal stability, flammability, and mechanical properties of the polymer matrix are investigated in detail. The catalytic application for activating peroxymonosulfate by ZIF-67 for contaminant degradation is also explored. With a small amount of ZIF-67/polymer nanocomposite films, more than 90% of methylene blue can be catalytically degraded in 25 min. This newly developed manufacturing approach can be extended to other functional polymers in combination with different MOFs to resolve global challenges in carbon neutrality and clean water.