Fabrication and characterization of biopolymer nanocomposites from natural resource materials

Abstract

In this study, nanocomposites of cashew tree gum (CTG) encapsulated nano‐magnetite (Fe3O4) was prepared and characterized by FTIR, UV–visible, X‐ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), magnetic and conductivity measurements. The characteristic absorption peaks in FTIR and UV–vis spectra of CTG was found to be shifted to higher wave numbers in CTG/Fe3O4 composite, which is due to the intermolecular interaction between nanoparticles and the CTG. The XRD patterns indicated that amorphous region of gum was decreased by the addition of metal oxide nanoparticles. SEM images show that nano‐Fe3O4 was uniformly dispersed in the cashew gum segments. DSC analysis revealed that the glass transition temperature and melting behavior of composites were higher than those of the pure gum. TGA results indicated that the thermal decomposition temperature of the composite increases with the increase in concentration of metal oxide nanoparticles. The magnetic properties studied by a vibrating sample magnetometer indicate that electromagnetism of CTG/Fe3O4 nanocomposites were superparamagnetic. The values of saturation of magnetization (Ms) and remanence (Mr) increases, while the coercivity (Hc) decreased with increase in Fe3O4 content in the composite. The AC electrical conductivity of the nanocomposites was significantly increased with the increase in Fe3O4 content in the nanocomposite. Due to the ordered structure of polymer composite, the dielectric constant and dielectric loss tangent (tan δ) of nanocomposites were also increased with increase in the concentration of nanoparticles. POLYM. COMPOS., 38:E66–E73, 2017. © 2016 Society of Plastics Engineers