Synergistic Effects of <scp>NiZIF67</scp>/<scp>GO</scp> Fillers on Water Vapor Transmission Rate of Waterborne Polyurethane Composite Films

ABSTRACT In this study, we investigated the potential of nickel and cobalt‐based Zeolitic Imidazolate framework (ZIF) NiZIF67 with graphene oxide (GO) composite fillers to reduce water vapor transmission rate (WVTR) in waterborne polyurethane (WPU) films. The NiZIF67/GO composite fillers were synthesized and characterized using various techniques like FESEM, XRD, and FTIR. These fillers were then incorporated into a WPU matrix to create composite films. The results suggest that the inter and intramolecular interactions within the NiZIF67/GO fillers effectively hinder water vapor permeation, leading to a significant decrease in WVTR compared to pristine WPU films. Furthermore, differential scanning calorimetry (DSC) analysis revealed an increase in both glass transition temperature ( T g ) and melting temperature ( T m ) with increasing filler content, indicating improved thermal stability of the composite films. Thermogravimetric analysis (TGA) confirmed this enhanced thermal stability, showing a higher onset degradation temperature with increased filler concentration. Additionally, X‐ray diffraction (XRD) analysis revealed an increase in the amorphous nature of the films, suggesting strong interactions between the fillers and the WPU matrix. This research demonstrates a promising approach for developing high‐performance barrier membranes using NiZIF67/GO composite fillers in WPU matrices for various applications including packaging films for fuel cells and batteries, electronics and sensors, agricultural packaging of seeds and pesticides.