No 2, Vol. 6, 2004, pages 169 - 175


M. Garcia1, G. van Vliet2, S. Jahin3, B. A. G. Schrauwen3, A. Sarkissov3, W.E. van Zyl4 and B. Boukamp1

1 Laboratory for Inorganic Materials Science, Faculty of Chemical Technology and MESA+ Research Institute,
University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
2 DSM Research, Material Science Center, P.O. Box 18, 6160 MD Geleen, The Netherlands
3 Department of Mechanical Engineering, Eindhoven University of Technology, P.O. Box 213, 5600 MB Eindhoven, The Netherlands
4 Department of Chemistry and Biochemistry, Rand Afrikaans University, P.O. Box 524, Auckland Park, 2006, South Africa


Polypropylene-SiO2 nanocomposites were synthesized using twin-screw extruders. The properties of the nanocomposites were studied using two different inorganic fillers: colloidal (sol) and powder silica nanoparticles. Reinforcing and toughening effects of the nanoparticles on the polymer matrix were found at a loading of 4.5 wt.%, which is lower than for most particulate filled composites. The use of silica nanoparticles led to different microstructure when compared with that of the pure polymer. Addition of colloidal silica to the polymer matrix produced good filler dispersion while the use of powder silica resulted in aggregated silica particles in the polymer matrix. There was no noticeable improvement of the mechanical properties when powder silica was added to the pure polymer. On the contrary, the presence of silica-sol nano-particles in the polymer matrix led to an increase of both Young modulus and impact strength, from 1.2 GPa to 1.6 Gpa and from 3.4 kJ/m2 to 5.7 kJ/m2 respectively.

full paper (pdf, 240 Kb)