Mechanical properties of glass beads filled polypropylene composites

In this study, the mechanical properties of glass beads filled polypropylene composites have been investigated. Polypropylene (PP) was filled with different volume fractions and different sizes of glass beads (GBs). The glass beads used were: 4, 11, and 66μm in diameters. Tensile specimens of PP/GB composites were injection molded and their mechanical properties were found by a series of uniaxial tensile tests. Young's modulus, work of fracture, Charpy impact strength and tensile strength of the specimens were determined. The results illustrated that the Young's modulus increased almost linearly with increasing glass bead concentration according to the Einstein equation. The work of fracture increased with the glass bead concentration until the maximum work of fracture was reached. Further increase in the glass bead concentration could cause the work of fracture to drop. Moreover, small toughening effect was resulted from filling PP with GBs. While there were improvements in the elastic modulus and the work of fracture, the tensile strength was however sacrificed. Increase in glass bead concentration caused the tensile strength to decrease. The fracture surface of the composite was examined by scanning electron microscope (SEM). Hence, the enhancement in the work of fracture was explained. © 1998 Trans Tech Publications.