title: Preparation and properties of aqueous castor oil-based polyurethane-silica nanocomposite dispersions through a sol-gel process.
abstract: Waterborne castor oil-based polyurethane-silica nanocomposites with the polymer matrix and silica nanoparticles chemically bonded have been successfully prepared through a sol-gel process. The formation of silica nanoparticles in water not only reinforces the resulting coatings, but also increases the crosslink density of the nanocomposites. The (29)Si solid state NMR spectrum indicates the formation of silica and the TEM indicates that the nanoparticles are embedded in the polymers, resembling a core-shell structure. The silica nanoparticles in the polymer matrix play an important role in improving both the mechanical properties and the thermal stabilities of the resulting nanocomposites. This work provides an effective and promising way to prepare biorenewable, high performance nanocomposite coatings.
authors: Department of Chemistry, Iowa State University, Ames, Iowa 50011, USA.
authors: Ying
authors: Y
authors: Xia
authors: Richard C
authors: RC
authors: Larock
mesh_terms: D002368:Castor Oil / Q000737:chemistry*; D020099:Coated Materials, Biocompatible; D008422:Materials Testing; D046529:Microscopy, Electron, Transmission; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D044367:Phase Transition; D011140:Polyurethanes / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D013499:Surface Properties; D014867:Water / Q000737:chemistry
chemical_list: D020099:Coated Materials, Biocompatible; D011140:Polyurethanes; D014867:Water; D012822:Silicon Dioxide; D002368:Castor Oil
keywords: castor oil; coatings; nanocomposites; polyurethane; silica