Rheological Investigation of Effect of Coupling Agent and Particle Size
on Processing of Polymer-Bonded Magnets

Joshua Otaigbe, Hyun Seog Kim, Jun Xiao, and Troy Tacke

Department of Materials Science and Engineering and Department of Chemical Engineering

Iowa State University,

Ames, IA, USA

Annual Technical Conference - Society of Plastics Engineers

Abstract

The effect of coupling agents and particle size on melt rheol. of polyphenylene sulfide-bonded neodymium-iron-boron (Nd-Fe-B) alloy magnets was studied with oscillatory flow expts. to accelerate efforts to optimize their processing. The min. viscosity of the polymer-bonded magnets near 290 ° was obtained with Nd-Fe-B fillers (106-150 particle size range) that were coupled with a silane coupling agent. All the samples tested followed power-law fluid flow behavior. Morphol. and dynamic mech. anal. of the samples showed that the beneficial function of the coupling agent may be ascribed to enhanced wetting of the magnetic Nd-Fe-B powders by the polymer, improving the processability of the polymer bonded magnets.