Orientation control of magnetically functionalized graphene oxide nanohybrids in unsaturated polyester resin with enhanced mechanical, thermal, and fire safety performance

Abstract Both the distribution and orientation of 2D graphene nanomaterials in polymer matrices can significantly affect the performance of polymer composites. Still, preparing high‐performance graphene polymer nanocomposites with a controlled distribution state is challenging. In this work, magnetically functionalized graphene oxide (MFGO), a ternary nanohybrid, was prepared using a facile method. The resulting MFGO nanofillers were incorporated into unsaturated polyester resin (UPR) with the assistance of an external magnetic field to achieve oriented alignment in the UPR matrix. Attributing to the uniform dispersion as well as the magnetic field‐induced orientation of MFGO in UPR, the oriented UPR/MFGO (UPR/OMFGO) nanocomposites demonstrated much‐improved mechanical and thermal properties, as the oriented UPR/MFGO2.0 (UPR/OMFGO2.0) achieved a notable increase in tensile strength to 46.71 MPa and storage modulus to 1.24 GPa. Moreover, the peak heat release rate (PHRR) and peak smoke production release (PSPR) of UPR/OMFGO2.0 nanocomposite were reduced by 34.0% and 33.6%, respectively, as compared with the neat UPR. In addition, SEM, FTIR, and Raman spectroscopy were employed to investigate the char residues of UPR samples, and a possible mechanism for the improved fire safety performance of the UPR/OMFGO nanocomposites was proposed. This work provides a promising strategy to design high‐performance UPR nanocomposites. Highlights Magnetically functionalized graphene oxide (MFGO) nanohybrids were successfully synthesized. MFGO nanohybrids were well dispersed and orderly arranged in UPR under a magnetic field. The well‐oriented MFGO significantly improved the mechanical and thermal properties of UPR. The mechanism for the enhanced fire safety performance of UPR nanocomposites was elaborated.