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Solvent-free nanofluids with surface functional groups composed of tetraalkylammonium ionic liquid organic salts and isothiocyanate decorating nanosilica cores are reported that ex- hibit viscous flow and glass transitions. These nanofluids when combined with hexamethylene diisocyanate and isophorone diiso- cyanate-polypropyleneglycol prepolymers are coated and auto- cured in humid air to produce thin films and clearcoats. These new resins are characterized thermally and by nanoindentation. Rela- tive to the air-cured prepolymer control, low nanofluid loading (1- 4% w/w) produces increased storage moduli and hardness and decreased loss factors. High loading (8 and 16%) results in soften- ing with increased toughness. While the control exhibited marked viscoelastic recovery, this recovery was largely arrested in the nanocomposite coatings. V C 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 3439-3448 |
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