Measurement of Dispersion of Glass Beads in PP Matrix

The dispersion of rigid inorganic particles (RIP) in polymer matrix is discussed and an equation for estimation of the dispersion is proposed. The dispersion of glass beads (GB) in polypropylene (PP) matrix and PP/ethylene-propylene-diene monomer co-polymer (EPDM) blend was measured by means of thermogravimetric analysis (TGA). It was found that the effects of the filler surface treatment and modification on the uniformity of the glass beads in the PP matrix was insignificant at low filler concentration. But the dispersion for the PP filled with the small glass beads was better than that of the big GB-filled system. Moreover, the values of the measured weight fraction of the glass beads were somewhat lower than those of the calculations for PP/EPDM/GB hybrid composites. In other words, no obvious cluster or aggregation phenomenon of the glass beads in the matrix occurs for these systems. It suggests that the uniformity of the glass bead dispersion for PP/EPDM/GB systems is relatively better than that of PP/GB systems.