Effect of Nickel-Cobalt-Zinc Ferrite Filler on Magnetic and Thermal Properties of Thermoplastic Natural Rubber Composites

摘要

A sample of Ni0.2Co0.25Zn0.5Fe2O4 ferrite was prepared by a double-staged sintering method in air.Thermoplastic natural rubber (TPNR) was prepared by melt blending of natural rubber (NR),liquid natural rubber (LNR),and high density polyethylene (HDPE) in an internal mixer Brabender Plasticorder PL 2000.Magnetic polymer composites were prepared from the ferrite and TPNR matrix using the same melt blending method at 135°C with mixing rate of 50 r.p.m.for 12 min.The fillers were varied from 5 to 30 weight percent.A uniform dispersion of the filler in the matrix was confirmed by thermogravimetric analysis (TGA).The density of the composites was determined using densitometer MD 200S.Magnetic properties were studied using a vibrating sample magnetometer (VSM) at room temperature (25°C).The results show that magnetization (M),saturation magnetisation (M_S),remanent magnetization (M_R),initial susceptibility (chi_i) and initial permeability (mu_i) increase with increasing filler content at all compositions.The composites can be classified as soft magnetic materials as their coercivities are in the range of 30-36 Oe.The differential scanning calorimetric (DSC) results indicate that the glass transition temperature (T_g) and the melting point (T_m) of all the composites are independent of the filler content.The thermal conductivity of the composites was found to be in the range of 0.26 to 0.52 Wm-1 K-1.