Novel ceramic-polymer composites synthesized by compaction of polymer-encapsulated TiO2-nanoparticles

Journal
Composites science and technology  
Volume
72
Issue
1
Start Page
65
End Page
71
Citation
Composites Science and Technology 72 (1): 65-71 (2011)
Publisher DOI
10.1016/j.compscitech.2011.10.001
Scopus ID
2-s2.0-81455153967
Publisher
Elsevier
A novel processing route for producing composites from ceramic particles and a thermoplastic polymer with high ceramic content was developed. Via a radical emulsion polymerization reaction in an aqueous suspension, titanium dioxide is encapsulated by a thin layer of poly(methyl methacrylate). Subsequently, the coated particles are compacted by applying high pressure (∼1GPa) at a temperature above the glass transition temperature of the polymer (∼160°C). This technique enables producing dense, hard and stiff composites at low processing temperatures. Microstructural investigations of composites by scanning electron microscopy confirm successful coating of titanium dioxide particles by polymer. Compositions were estimated from thermogravimetric measurements. A maximum TiO2 volume content of almost 70% was achieved. For characterizing mechanical properties, Vickers microhardness as well as flexural strength and elastic modulus were determined. With respect to pure PMMA, composites exhibit a 10-fold increase in microhardness. Furthermore, a strong increase in elastic modulus with TiO2 contents, up to 40GPa at 66vol.% TiO2 was observed. These moduli are among the highest found in literature for ceramic polymer composites. However, bending strength of the material is still low.
Subjects
A. Hybrid-composites
A. Particle-reinforced composites
A. Structural composites
B. Mechanical properties
Polymer-encapsulation
DDC Class
600: Technik
620: Ingenieurwissenschaften