The continuous advancement of materials science has highlighted the ongoing need for additional studies on the main composite materials topics, particularly in the field of multifunctional nano-composites, towards improving their capability to meet multifaceted requirements in order to stimulate both scientific and technological development. In this study, we report the preparation and characterization of polyetherimides (PEIs) derived from 4,4'-(4,4'-isopropylidenediphenoxy) bis (phthalic anhydride) following a two-step polycondensation reaction using either 4,4'-(1,3-phenylenedioxy) dianiline, or Jeffamine ED-600 as comonomers, or a mixture of the two diamines. Based on the PEI containing flexible Jeffamine segments, polymer composite films were developed by incorporating BaTiO3 particles. The chemical structure and morphology of the composite films were investigated by FTIR spectroscopy and scanning electron microscopy. Thermal properties were determined by thermogravimetric analysis and differential scanning calorimetry. The influence of Jeffamine segments on the thermal decomposition process was investigated by TG/MS/FTIR measurements under air and nitrogen atmospheres. Based on the obtained data, the thermal decomposition mechanism was established and is discussed in accordance with the chemical structures of the polymers. The surface properties of the PEI and PEI-composite films were characterized by performing contact angle measurements. The addition of BaTiO3 increased the wettability of the surfaces. The dielectric characteristics of polymer composite films were investigated by broad band dielectric spectroscopy measurements. It was noticed that the addition of BaTiO3 nanoparticles to the copolymer matrix gradually enhanced the dielectric constant of the composites.
Keywords: Jeffamine segments; contact angle; dielectric properties; polyetherimides; thermal decomposition mechanism.