Polymer-Montmorillonite Nanocomposites Through Controlled Radical Polymerization Using (4-Vinylbenzyl) Triethylammonium Anchored Organo-Montmorillonite

Abstract

Novel (4-vinylbenzyl) triethylammonium anchored organo-montmorillonite was synthesized and used to prepare polymer-montmorillonite nanocomposites through controlled radical polymerization. For the synthesis of polymer-montmorillonite nanocomposites, methyl methacrylate and styrene were separately polymerized using thermal iniferter, 1,1,2,2-tetraphenylethane-1,2-diyl bis(2-bromo-2-methylpropanoate), in the presence of (4-vinylbenzyl) triethylammonium anchored organo-montmorillonite. The morphology of the nanocomposites was studied with the help of X-ray diffraction and transmission electron microscope (TEM), and thermal properties were studied using differential scanning calorimetry and thermogravimetric analysis. TEM analysis results showed the formation of highly exfoliated nanocomposites along with the intercalated nanocomposites. The use of monomer anchored montmorillonite enhanced the exfoliation of montmorillonite, due to this, enhanced T_g up to 10°C and enhanced thermal stability up to 50°C were observed. As the polymerization time increases, there is an increase in both conversion and molecular weight. Due to this, the quantity and molecular weight of polymers incorporated inside the galleries can easily be controlled merely by changing polymerization time. As a result, intercalation/exfoliation of montmorillonite galleries can be controlled easily.

Keywords:

• nanocomposites
• controlled radical polymerization
• iniferter
• polystyrene
• poly(methyl methacrylate)
• organo-montmorillonite
• vinylbenzyl chloride

Acknowledgments

The authors thank Dr. Govind Gupta and Mr. Ravinder Kumar for analytical help.

Additional information

Funding

The authors thank University Grants Commission for financial support to this project.