Investigations on the structural,mechanical, thermal,and electrical properties of Ce-doped TiO2/poly(n-butyl methacrylate) nanocomposites

This study focused on the fabrication of poly(n-butyl methacrylate) (PBMA) nanocomposites with various concentrations of cerium-doped titanium dioxide (Ce–TiO₂) nanoparticles via in situ polymerization technique. The structural characterization and the material properties of all the composites were analyzed by UV–visible, FTIR, XRD, SEM, DSC, TG, and tensile strength measurements. The UV–visible and FTIR studies confirmed the effective inclusion of Ce–TiO₂ nanoparticles into the PBMA matrix. The change in amorphous morphology of PBMA to a crystalline structure was observed from the XRD pattern. The SEM morphology revealed the attachment of nanoparticles in the polymer matrix. The inclusion of Ce–TiO₂ nanoparticles enhanced the glass transition temperature, and thermal stability of the PBMA matrix was revealed from DSC and TG, respectively. The tensile strength of PBMA was greatly enhanced by the addition of Ce–TiO₂ nanoparticles. The AC conductivity, dielectric constant, and dielectric loss studies were also performed in the frequency range 10²–10⁶ Hz, and it was observed that addition of Ce–TiO₂ nanoparticles greatly enhanced the electrical properties of PBMA. The change in dielectric constant with the addition of nanoparticles was correlated with a theoretical modeling study. This work also extended to study the role of Ce–TiO₂ nanoparticles in the reinforcing mechanism of the nanocomposite by comparing the actual tensile strength of the composite with different theoretical modeling. The high dielectric constant and tensile strength of composite are beneficial in designing lightweight and highly efficient nanoelectronic materials based on the family of polybutyl acrylates.

     

Effect of temperature on AC conductivity of poly(butyl methacrylate)/cerium dioxide nanocomposites and applicability of different conductivity modeling studies

In this research, the effect of cerium dioxide (CeO₂) nanoparticles on electrical properties of poly(butyl methacrylate) (PBMA) has been investigated. Polymer nanocomposites reinforced with variable contents of CeO₂ nanoparticles (3, 5, 7 and 10 wt%) were fabricated by an in situ polymerization method. The formation of nanocomposites was analyzed by FTIR, XRD, SEM and TEM analysis. Also, the AC and DC conductivities of CeO₂ nanoparticles-reinforced PBMA were systematically studied with respect to different loadings of CeO₂ fillers. The FTIR, XRD and morphological studies revealed that the nanoparticles were well inserted and uniformly dispersed into the macromolecular chain of PBMA. The AC conductivity of PBMA/CeO₂ composite increases not only with the loading of nanoparticles but also with the temperature of the system. The activation energy determined from AC electrical conductivity was found to decrease with the frequency and temperature. DC conductivity of the nanocomposites was increased with the insertion of nanoparticles into PBMA. The DC conductivity of all the composites was greater than pure PBMA. The applicability of different theoretical models such as Scarisbrick, Bueche and McCullough equations was compared with the experimentally determined DC conductivity of PBMA/CeO₂ nanocomposites. These models fail to explain the conductivity of polymer composite in the entire loading of fillers. Hence, a new theoretical model is proposed in this study and it shows good agreement with the experimentally observed conductivity values.