Bio-Based Hybrid Magnetic Latex Particles Containing Encapsulated γ -Fe2O3 by Miniemulsion Copolymerization of Soybean Oil-Acrylated Methyl Ester and Styrene

Abstract

This work reports the use of acrylated fatty acid methyl ester (AFAME) as a biomonomer for the synthesis of bio-based hybrid magnetic particles poly(styrene-co-AFAME)/γ-Fe2O3 produced by miniemulsion polymerization. Poly(styrene-co-AFAME)/γ-Fe2O3 can be tailored for use in various fields by varying the content of AFAME. The strategy employed is to encapsulate superparamagnetic iron oxide nanoparticles (SPIONs) as γ-Fe2O3 into a styrene/AFAME-based copolymer matrix. Raman spectroscopy is employed to ensure the formation of the SPIONs (γ-Fe2O3) obtained by a co-precipitation technique followed by oxidation of Fe3O4. The functionalization of SPIONs with oleic acid (OA) is carried out to increase the SPIONs–monomer affinity. The presence of OA on the surface of γ-Fe2O3 is certified by identification of main absorption bands by fourier-transform infrared spectroscopy (FTIR). Thermal analysis (differential thermogravimetry/differential thermo analysis and differential scanning calorimetry) results of poly(styrene-co-AFAME)/γ-Fe2O3 show an increase in AFAME content leading to a lower copolymer glass transition temperature (T g). Dynamic light scattering (DLS) measurements result in poly(styrene-co-AFAME)/γ-Fe2O3 particles with diameter in the range of 100–150 nm. It is also observed by transmission electron microscopy (TEM) and cryo-TEM techniques that γ-Fe2O3 particles are successfully encapsulated into the poly(styrene-co-AFAME) matrix.