Preparation and applications of novel fluoroalkyl end-capped sulfonic acid oligomers–silica gel polymer hybrids

Abstract

Fluoroalkyl end-capped 2-methacryloxyethanesulfonic acid homo-oligomer [RF–(MES)n–RF] and 2-methacryloxyethanesulfonic acid–N,N-dimethylacrylamide co-oligomers [RF–(MES)x–(DMAA)y–RF] reacted with tetraethoxysilane (TEOS) under acidic conditions to afford RF–(MES)n–RF homo-oligomer–SiO2 polymer hybrid and RF–(MES)x–(DMAA)y–RF co-oligomer–SiO2 polymer hybrid, respectively. Thermogravimetric–mass spectra showed that the thermal stability of RF–(MES)n–RF homo-oligomer–SiO2 polymer hybrid was superior to that of traditionally well-known perfluorinated ion exchange polymers such as Nafion 112 (TR). The sol solutions of the fluorinated co-oligomer–SiO2 polymer hybrid were applied to the surface modification of glass to exhibit not only a strong oleophobicity imparted by fluorine but also a good hydrophilicity on the glass surface. On the other hand, RF–(MES)x–(DMAA)y–RF co-oligomer reacted with TEOS in the presence of a variety of silica nanoparticles (mean diameters: 11–95 nm) under alkaline conditions to afford fluoroalkyl end-capped oligomers–silica nanoparticles (mean diameters: 32–173 nm) with a good dispersibility and stability in methanol. Similarly, a variety of fluorinated oligomers containing sulfo groups–silica nanoparticles were prepared by the homo- and co-oligomerizations of fluoroalkanoyl peroxides with 2-methacryloxyethane sulfonic acid (MES) and comonomers such as N,N-dimethylacrylamide (DMAA) and acryloylmorpholine (ACMO) in the presence of silica nanoparticles. Interestingly, these isolated fluorinated particle powders were found to afford nanometer size-controlled colloidal particles with a good redispersibility and stability in aqueous and organic media such as methanol. These fluorinated nanoparticles containing sulfo groups were also applied to an excellent heterogeneous catalyst for Bronsted acid-catalyzed transformations. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 110–117, 2007