Poly(methyl methacrylate)/magnetite (PMMA/Fe3O4) nanocomposites were prepared with a two–step technique involving sonication. Fe3O4 nanoparticles were synthesized by ultrasound–assisted co–precipitation, and then PMMA/Fe3O4 (1–5 wt%) nanocomposites were synthesized via ultrasound–assisted in–situ emulsion polymerization. Best physical properties of the nanocomposites for different Fe3O4loadings were: Tensile strength (2 wt%) = 40.28 MPa, Young’s modulus (2 wt%) = 2.4 GPa, percentage elongation (2 wt%) = 2.24%, glass transition temperature (2 wt%) = 122.5 °C, thermal inflection point (2 wt%) = 383 °C, electrical conductivity (5 wt%) = 2.0 × 10–13 S/cm, coercivity = 59.85 Oe (2 wt%), magnetic saturation (5 wt%) = 5.12 emu/g, magnetic remanence (5 wt%) = 0.56 emu/g, and electromagnetic interference shielding effectiveness (5 wt%) = 1.45 dB. This unique combination of physical properties at relatively low Fe3O4 loading is attributed to ultrasound–mediated uniform dispersion of the nanofiller in the polymer matrix.
Available online 21 December 2017