The magnetic and conducting properties of polypropylene (PP)-reduced graphene oxide (rGO)-carbon nanotube with iron (CNT-Fe) nanocomposites prepared by melt mixing were studied. CNT-Fes were synthesized by the pyrolysis of sawdust, and rGO was produced from graphite flakes. The combination of these two materials was used to produce magnetic and conducting properties in a diamagnetic and insulating PP matrix with the addition of a small amount of filler. A constant and minute amount of CNT-Fes was sufficient to introduce magnetic characteristics to the PP matrix. A variable amount of rGO was used, and the percolation threshold was achieved with the use of only 2.1 wt % rGO. All samples reached magnetic saturation at about 4.2 kOe, with an identical coercivity of 150 Oe and a normalized remnant magnetization of 0.14. Thermogravimetric and differential scanning calorimetry analyses showed enhancements in the maximum degradation temperature, melting temperature, crystallization temperature, and crystallinity. The nanocomposites showed better mechanical and barrier properties than the neat polymer. The novelty of this study was the use of a filler derived from waste combined with rGO to obtain a thermoplastic nanocomposite with both magnetic and conducting properties at room temperature. V C 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46820.

Magnetic polypropylene (PP) nanocomposites with different loadings (from 0.5 to 20 wt %) of carbon nanotubes with iron (CNT-Fe) were fabricated using the melt-mixing method. The carbon nanotubes were synthesized by pyrolysis of sawdust from the furniture industry. The morphological characterization shows homogenous dispersion of the filler in the polymer matrix. The addition of only 0.5 wt % CNT-Fe already results in ferromagnetic behavior in the diamagnetic polymer matrix. The thermal properties were investigated using thermogravimetric analysis and differential scanning calorimetry. The results show an increase in the maximum degradation, crystallization, and melting temperatures of the nanocomposites compared with neat PP. The nanocomposites showed improvement in terms of mechanical and oxygen permeability properties. A very significant result of the work is the high remnant magnetization and coercivity values of the nanocomposites at room temperature whereas most of the works on similar systems show magnetic properties only at very low temperatures.