Synthesis of Poly(2-ethylhexyl acrylate)/Clay Nanocomposite by In Situ Living Radical Polymerization

This investigation reports the preparation of tailor-made poly(2-ethylhexyl acrylate) (PEHA) prepared via in situ living radical polymerization in the presence of layered silicates and characterization of this polymer/clay nanocomposite. Being a low T-g (-65 degrees C) material, PEHA has very good film formation property for which it is used in paints, adhesives, and coating applications. 2-Ethylhexyl acrylate was polymerized at 90 degrees C using CuBr and Cu(0) as catalyst in combination with N,N,N',N '',N ''-pentamethyl diethylenetriamine (PMDETA) as ligand. A tremendous enhancement in reaction rate and polymerization data was achieved when acetone was added as additive to increase the efficiency of the catalyst system. PEHA/clay nanocomposite was prepared at 90 degrees C using CuBr as catalyst in combination with PMDETA as ligand. Different types of clay with same loading were also used to study the effect on reaction rate. The molecular weight (Mn) and polydispersity index of the prepared nanocomposites were characterized by size exclusion chromatography. The active end group of the polymer chain was analyzed by H-1 NMR analysis and by chain extension experiment. Polymer/clay interaction was studied by Fourier Transform Infrared spectrometry and wide-angle X-ray diffraction analyses. Distribution of clay in the polymer matrix was studied by the transmission electron microscopy. Thermogravimetric analysis showed that thermal stability of PEHA/clay nanocomposite increases on addition of nanoclay. (C) 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 1564-1571, 2011