Characterization of magnetic microspheres based on network styrene and divinylbenzene copolymers

Spherical microparticles based on poly(styrene-co-divinylbenzene), capable of responding to magnetic fields, were obtained by suspension of copolymerization of styrene (STY) and divinylbenzene (DVB) in the presence of fine iron particles. The polymerization reaction was carried out in aqueous media using 2-hydroxyethylcellulose combined with gelatin as suspension stabilizers. The specific area and average porous diameter of the network composite microspheres were determined. The optical microscopy and the scanning electron microscopy were employed to investigate the composites morphology and the iron dispersion. Energy dispersive X-ray was also used to evaluate the iron particles distribution. In the presence of fine iron particles in the polymerization mixture and under suitable conditions, magnetic microspheres with relatively narrow size distribution were formed. The micrographies showed that agglomerated iron particles were only present on the microsphere surface. The coercive force of the microsphere composites increased with the increasing iron content in the particles.