Synthesis and characterization of an exfoliated modified syndiotactic polystyrene/Mg-Al-layered double-hydroxide nanocomposite

This paper describes the synthesis and characterization of a controlled graft and block copolymerization onto syndiotactic polystyrene (sPS) using nitroxide-mediated living radical polymerization and the preparation of its polymer/layered double-hydroxide (LDH) nanocomposite. The graft and block copolymerization of styrene and p-methylstyrene were initiated with arylated sPS carrying 2,2,6,6-tetramethyl-1-piperidinyloxy groups as a macroinitiator. The structures of obtained graft and block copolymers were determined by H-1 nuclear magnetic resonance and Fourier transform infrared spectroscopy. The MgAl(Cl)-LDH precursor was prepared with microwave irradiation using a mixed solution of MgCl2 and AlCl3, which was slowly pumped into decarbonated water. Thereafter, the surfactant-modified MgAl(SDBS) was obtained by the anion exchange reaction of MgAl(Cl)-LDH with sodium dodecyl benzene sulfate (SDBS). Finally, the sPS-g-(PS-b-PMS)/MgAl-LDH nanocomposite was prepared by a solution intercalation method. The exfoliated structure of the nanocomposite was probed by X-ray diffraction and transmission electron microscopy (TEM). Compared with pure sPS-g-(PS-b-PMS), the nanocomposite shows a much higher decomposition temperature and higher glass transition temperature. Polymer Journal (2011) 43, 186-193; doi: 10.1038/pj.2010.127; published online 15 December 2010