In Situ Polymerization of Barium Hexaferrite Ferrofluids for Poly(Ethylene) Succinate Magnetic Nanoparticle Composites

ABSTRACT The integration of hard magnetic barium hexaferrite (BHF) nanoplatelets into a dense poly(ethylene succinate) (PES) polyester matrix produces an exciting biodegradable thermoplastic magnetic polymer nanocomposite. In this work, scandium‐substituted BHF nanoplatelets are grown and stabilized in hexadecyltrimethylammonium bromide (CTAB) surfactant and subsequently dispersed in ethylene glycol, producing a stable ferrofluid. The ferrofluid is used for an in situ step‐growth condensation polymerization reaction between the ethylene glycol‐based ferrofluid and succinic acid. The polymerized ferrofluid forms a hard magnetic nanocomposite with filler content of up to 4.5 wt% of BHF nanoplatelets, which are homogeneously dispersed within a solid polymer matrix. With a filler content 16 times higher than in previous studies, the nanocomposite was chemically analyzed using Fourier Transform Infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, and gel‐permeation chromatography (GPC) and optimized for chain length and molecular weight, reaction time and temperature, magnetic moment, and surface hardness. The polymer molecular weight was found to be 1359 g/mol with a monomer‐to‐polymer conversion of 89%. Highly dense polymer composites were characterized using thermogravimetric analysis (TGA), while magnetic properties were determined by vibrating sample magnetometry (vsm). The synthesized magnetic thermoplastic polymer composite shows excellent magnetic properties, opening the way to advanced 3D magnetic printing and biomedical applications.