A novel epoxy adhesive with metal organic framework (MOF) and poly(butyl acrylate-block-styrene) for bonding aluminum-aluminum joints: A complete overview of mechanical, thermal, and morphological properties

In this study, MIL-101 (Cr) and NH2-MIL-101 (Cr) nanoparticles were synthesized by hydrothermal method. Butyl acrylate-styrene copolymer was used along with these nanoparticles to improve the mechanical properties of epoxy adhesive. The results of the Fourier Transform Infrared (FTIR) and X-ray diffraction (XRD) test showed that the synthesis and functionalization of the metal organic framework (MOFs) were successful. The mechanical properties and adhesion features in the lap joint bonding of aluminum foil to the aluminum foil of modified epoxy adhesives were investigated by tensile and lap shear tests. The results of the tensile test showed that by adding 0.3 wt% of NH2-MIL-101 (Cr) and 2.5 wt% of poly(butyl acrylate-block-styrene) to epoxy adhesive, the tensile strength, modulus and toughness of dumbbell samples were increased up to 34.46%, 31.74% and 58.53%, respectively. Furthermore, based on the lap shear test results, by adding 0.3 wt% NH2-MIL-101 (Cr) along with 2.5% poly(butyl acrylate-block-styrene) to the epoxy adhesive, the lap shear strength of samples increased from 1.05 +/- 0.08 MPa to 5.25 +/- 0.06 MPa compared to the neat epoxy adhesive. According to the TGA test, the highest thermal stability is related to the sample containing 0.3 wt% of NH2-MIL-101 nanoparticles and 2.5 wt% of the copolymer. The image of the fracture surface of the sample containing 0.3 wt%. NH2-MIL-101 (Cr) and 2.5 wt% block copolymer shows that the interface of nanoparticles and the matrix improved due to the chemical reaction of functional groups of nanoparticles and adhesive matrix.