Synthesis and Characterization of Dual-Functionalized Laponite Clay for Acrylic Nanocomposites
Chemistry and Biochemistry
Dual-functional laponites were synthesized by a condensation reaction with silane coupling agents followed by cation exchange reaction with quaternary ammonium salts. FTIR and solid state C-13 CP/MAS NMR confirmed their structures. Quantitative solid state Si-29 DP/MAS NMR spectra indicated that clay silanol groups reacted with silane coupling agents by a decrease in the silanol peak and appearance of a new Si-O-Si peak. Dual-functionalized laponites showed improved dispersion in organic solvents and vinyl monomers. One dual-functional laponite modified with both photosensitizer and coinitiator photo-initiated polymerization of an acrylate (2-phenoxyethyl acrylate, PEA) and a methacrylate (MHMA, methyl alpha-hydroxymethylacrylate). TEM showed laponite clay sheets were exfoliated in poly(PEA); while a combination of exfoliated, intercalated and tactoid morphologies was found in poly(methyl alpha-hydroxymethylacrylate). The other dual-functionalized laponite clay with edge-bound methacrylate units copolymerized with methyl methacrylate and led to a high grafting amount and graft efficiency. PMMA nanocomposites showed higher storage modulus both below and above the glass transition temperature compared to the PMMA control. (C) 2007 Wiley Periodicals, Inc.
Journal of Applied Polymer Science
Jarrett, W. L.,
(2007). Synthesis and Characterization of Dual-Functionalized Laponite Clay for Acrylic Nanocomposites. Journal of Applied Polymer Science, 106(3), 1496-1506.
Available at: http://aquila.usm.edu/fac_pubs/12876