Highly dispersed thermally reduced graphene oxide in polypropylene assisted with in-situ Friedel-Crafts reaction and its thermo-oxidative stabilization effect

Achieving uniform dispersion of nanofillers in a polymer matrix, particularly for incompatible compounds, remains a formidable challenge. In this study, thermally reduced graphene oxide (TrGO) sheets were effectively dispersed within a nonpolar polypropylene (PP) matrix using a two-step approach, leveraging the Friedel–Crafts reaction catalyzed by AlCl3. The results showed that the size and number of TrGO aggregates were significantly reduced after AlCl3 treatment. The thermo-oxidative stability in terms of oxidation induction time (OIT) of the PP/TrGO(Al) composite further improved by 2 times when 0.1 wt% TrGO was added to the PP matrix compared with that of the samples without AlCl3 treatment. The improved thermo-oxidative stability and mechanical properties of PP/TrGO(Al) can be attributed to its superior radical scavenging efficiency, oxygen barrier effect, and effective load transfer afforded by the excellent dispersion of TrGO. This research highlights a pioneering methodology for enhancing both the dispersion of TrGO in a nonpolar polymer matrix and the thermo-oxidative resilience of the resultant composites.