Synthesis of polyethylene/nickel-carbon stimuli-responsive material under magnetic field at room temperature: Effect of the filler on the properties

In this study we investigated the effect of carbon-based magnetic fillers on the thermal, mechanical, morphological and magnetic properties of polyethylene nanocomposites, with the filler range from 0 to 8.5 wt%, prepared by in situ polymerization. The nickel-carbonized material was prepared from biomass by the pyrolysis of wood sawdust. The thermal stability was investigated by thermogravimetric analysis (TGA) and differential calorimetric analysis (DSC); the results show that, with incorporation of the filler, the onset and maximum degradation temperatures increased by 24 and 7 degrees C, respectively. The DSC results indicate an enhancement of 4 degrees C in the melting and crystallization temperatures, as compared to neat polyethylene. The addition of the Ni filler resulted in a ferromagnetic behavior of the polyethylene nanocomposites. While the variation on the coercivity with the Ni filler content was very little (a rise of similar to 30%), the effect on the normalized remnant magnetization was rather significant, presenting a threefold increase. The mechanical properties showed an improvement, mainly with the higher amount of the filler.