Alexandros K. Nikolaidis*, Elisabeth A. Koulaouzidou and Dimitris S. Achilias Pages 512 - 524 ( 13 )
Background: Nanoclays incorporated in dental resins have been previously investigated. However, limited reports are associated with nanoclays that exhibit high functionality.
Objective: The aim of this study was the targeted synthesis and characterization of organomodified nanoclays with methacrylic groups suitable for incorporation in dental nanocomposite resins.
Methods: Quaternary ammonium methacrylates were synthesized and characterized by means of proton nuclear magnetic resonance and Fourier-transform infrared spectroscopy. Consequently, they were inserted into the interlayer space of nanoclay through a cation exchange reaction, while silane was also used for simultaneous surface modification. The produced organomodified nanoclays were characterized by means of X-ray diffraction, Fourier-transform infrared spectroscopy and thermogravimetric analysis.
Results: Fourier-transform infrared spectra confirmed the successful synthesis of the quaternary ammonium methacrylates. X-ray diffraction analysis showed that organoclays exhibited higher d001- values (up to 1.78 nm) compared to raw nanoclay (1.37 nm), indicating an accomplished intercalation in each case. X-ray diffraction spectra mainly disclosed the presence of methacrylic functional groups in all nanoclays. Thermogravimetric analysis curves verified the different thermal stability of organoclays due to the diversity of their organic modifiers.
Conclusion: The experimental results showed that nanoclay was successfully modified with ammonium methacrylates and silane. Τhe combination of X-ray diffraction and thermogravimetric analysis data revealed a high degree of intercalation and methacrylated organic loading as well. These phenomena may favor a good dispersion and high polymerization degree of nanoclays with dental resin monomers, rendering them potentially useful materials for the development of advanced dental nanocomposites resins.
Organically modified clay, cation exchange reaction, quaternary ammonium methacrylate, silane, nanocomposite, dental resin.
Division of Dental Tissues’ Pathology and Therapeutics (Basic Dental Sciences, Operative Dentistry, Endodontology), School of Dentistry, Aristotle University Thessaloniki, Thessaloniki 541 24, Division of Dental Tissues’ Pathology and Therapeutics (Basic Dental Sciences, Operative Dentistry, Endodontology), School of Dentistry, Aristotle University Thessaloniki, Thessaloniki 541 24, Laboratory of Polymer and Color Chemistry and Technology, Department of Chemistry, Aristotle University Thessaloniki, Thessaloniki 541 24