Thermogravimetry and Dynamic Mechanical Analysis of Iron Silicon Particle filled Polypropylene

Abstract

Thermogravimetric and dynamic mechanical behavior of extruded and injection molded polypropylene (PP) samples with additives and varying volume fractions (0, 4.5, 14, 21, and 39 vol%) of soft magnetic iron silicon (FeSi) particles with a mean particle diameter of 58 μm were analyzed. With increasing filler volume fraction, thermogravimetry shows enhanced thermal stability of PP. Dynamic mechanical analysis (DMA) was performed at temperatures between 200 and 400 K at discrete vibrating frequencies between 10-1 and 101 Hz. Loss factor tanδ of all examined materials shows typical peaks (α, α' and β) of phase transitions in the crystalline and amorphous polymer structure of PP in this temperature range. Storage modulus E' at 200 K starts at 2283 MPa for PP with additives (stabilizers, antioxidants, lubricants, desactivators, and surface activators) and increases up to 7175 MPa for 39 vol% iron silicon fraction. The activation energy at α—peak reduces with increasing filler volume fractions.