Polycarbonate reinforced with silica nanoparticles

• Published in: Polymer bulletin (Berlin, Germany) Vol. 66; no. 7; pp. 991 - 1004
• Main Authors: Luyt, A. S., Messori, M., Fabbri, P., Mofokeng, J. P., Taurino, R., Zanasi, T., Pilati, F.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01-04-2011; Springer; Springer Nature B.V
• Subjects: Applied sciences; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Complex Fluids and Microfluidics; Composites; Energy dissipation; Exact sciences and technology; Forms of application and semi-finished materials; Hydrophilicity; Impact resistance; Load; Load shifting; Mechanical properties; Nanocomposites; Nanoparticles; Nitrogen; Organic Chemistry; Original Paper; Particle size; Penetration resistance; Physical Chemistry; Polycarbonate resins; Polymer industry, paints, wood; Polymer melts; Polymer Sciences; Rheological properties; Rheology; Scratch resistance; Silica; Silicon dioxide; Soft and Granular Matter; Technology of polymers; Temperature; Thermal analysis; Thermogravimetric analysis; Germany; Silica nanoparticles; Dynamic mechanical properties; Polycarbonate; Impact and scratch resistance; Viscoelasticity; Mixing; Mechanical properties; Dispersion reinforced material; Hardness; Experimental study; Silica; Composite material; Score strength; Impact strength; Concentration effect; Nanocomposite; Rheological properties
• ISSN: 0170-0839; 1436-2449
• DOI: 10.1007/s00289-010-0408-5

Nanocomposites of polycarbonate (PC) reinforced with nanosized silica particles were prepared by a melt mixing technique in an internal mixer. Two kinds of commercial hydrophilic fumed silicas differing in their specific surface area were added in amounts up to 5% by volume, and their reinforcing action was compared to that of organically modified silica, loaded in the same amounts. Particle–matrix interactions were investigated by means of rheological and dynamic-mechanical thermal analysis, demonstrating the important role played by the organic modification in the interactions with the polymer matrix, and showing an optimal nanoparticle loading around 2 vol%. The scratch resistance of the nanocomposites obtained from hydrophilic silicas was investigated, and a remarkable enhancement in the indenter’s penetration resistance was observed for all the compositions with respect to pristine PC. The same behaviour was observed for the Shore D hardness and for the impact resistance of the nanocomposites that also significantly improved with the maximum load shifting from a minimum value of 521 N for pristine PC up to values grater than 1330 N for the nanocomposites, demonstrating the activation of effective mechanisms of energy dissipation due to the presence of the nanofillers.