In-Situ Nanocomposite Synthesis: Arylcarbonylation and Grafting of Primary Diamond Nanoparticles with a Poly(ether−ketone) in Polyphosphoric Acid

Abstract

In a model reaction to demonstrate the presence and reactivity of sp2 C−H, the primary particles (∼5 nm) of detonation nanodiamond (DND) were arylcarbonylated with 2,4,6-trimethylphenoxybenzoic acid in polyphosphoric acid (PPA) via a Friedel−Crafts reaction. The possibility of grafting primary DND particle was supported by the results from FTIR, scanning electron microscopy (SEM), and elemental analysis. From the latter result, we estimated the degree of functionalization to be ∼2.3 atom %. The arylcarbonylated DND achieved better and stable dispersion than pristine DND in common organic solvents. PPA-treated DND from the control experiment retained most of the pristine DND’s properties, except that its thermo-oxidative stability is noticeably improved as indicated by the result from thermogravimetric analysis (TGA in air). Subsequently, 3-phenoxybenzoic acid (PBA) was polymerized in PPA with the pristine DND (1.0−30 wt %) in situ to generate meta-poly(ether−ketone)-grafted DND composites, mPEK-g-DND. It ...