Polymer-Bonded Magnets: Part I. Analytic Thermogravimetry to Determine the Effect of Surface Modification on Dispersion of Nd-Fe-B Fillers.

Xiao, Jun; Otaigbe, Joshua U.

Department of Materials Science and Engineering

Iowa State University of Science and Technology,

Ames, IA, USA

Abstract

The degree of mixing is a crit. factor in controlling the magnetic properties and mech. properties of polymer-bonded magnets. Pretreatment of the NdFeB fillers with a silane coupling agent improved the degree of mixing of the fillers in the polymer matrix, poly(p-phenylene sulfide), due to good wetting as evidenced by viscosity redn. of the coupled polymer-bonded magnets. Thermogravimetric anal. methods were used to quantify the degree of mixing of the polymer-bonded magnets. The intensity of segregation was calcd. from the measured wt. change of the magnetic filler in the samples. The thermogravimetric anal. method was useful in detg. the degree of mixing of NdFeB fillers in polymer-bonded magnets.