The Effect of Surface Treatment of Magnetite Powder on a Structure of Composite Particles Prepared by Suspension Polymerization

Abstract

Composite particles composed of poly(styrene-co-n-butyl acrylate) and magnetite powder treated with the various coupling agents were prepared by using suspension polymerization. The effect of the surface treatment by coupling agents on the structure of composite particles was mainly investigated by observing the dispersion state of magnetite powder in composite particles and triboelectric charge property. The treatment by the coupling agents with an unsaturated carbon bond and hydrophobic group of a long carbon chain resulted in a better inclusion of magnetic powder into composite particles. The coupling agent species greatly affected the triboelectric charge property of composite particles.It was found that a specific coupling agent with a high polarity acted as the charge controlling agent for the toner application. The effect of the surface treatment on the particle size distribution was also discussed.