Characterisation of poly(methyl methacrylate) film deposited on iron powder particles by electropolymerization

Iron powder microparticles were coated with a poly(methyl methacrylate) (PMMA) film by electropolymerization in a fluidised bed reactor. The formation of a PMMA coating on the microparticles’ surface was studied with pyrolysis gas chromatography (Py-GC) fingerprinting as well as time-of-flight secondary ion mass spectrometry (TOF-SIMS). While Py-GC can provide information about PMMA bulk formation and quick information about PMMA deposition on iron microparticles, TOF-SIMS can give detailed information about particle surface PMMA coatings. A TOF-SIMS study was performed in both, positive and negative ion modes with Bi+ and Bi 3 + primary ions. Static TOF-SIMS macroscans of powder microparticle surface resulted in the identification of the regions with species related to the PMMA fragments in the negative ion region ( Bi 3 + ) . TOF-SIMS results confirmed that PMMA coating on the iron powder microparticle surface formed an incoherent and inhomogeneous film. PMMA coating was somewhere very thin to supply a sufficient positive charged secondary ion signal. Plating of metallic powder particles by polymeric coating enables the modification of surface and structural properties of materials used in powder metallurgy. PMMA coated iron powder microparticles can be innovative as lubricants in such a way that, when they are subjected to pressure, they burst and release carbon to metal powder. The main aim of this research work is to characterise PMMA coatings deposited by electropolymerization on the surface of iron powder microparticles.