Waterborne polyurethane nanocomposites having shape memory effects

Abstract

UV curable waterborne polyurethane/silica nanocomposites were designed and synthesized with functionalized silicas, where the functionalization was made with allyl isocyanate. The incorporated silica particles gave triple effects of multifunctional chemical cross-links, reinforcing fillers, and stress relaxation retarders. Consequently, functionalized silica incorporated into the polymer chains showed significantly improved mechanical and thermal properties than the simple addition of unmodified silica. Notably, over 99% shape fixity and shape recovery with minimum cyclic hysteresis were obtained for the repeated cycles at 1% loading of the modified silica

Preparation and properties of Waterborne polyurethane/nanosilica composites: A diol as extender with triethoxysilane group

“…Among these modification, incorporation of nanosilica into WPU has attracted much attention due to the synergetic effect between nanosilica and polyurethane, which are expected to produce novel and desired performances. In addition, nanosilica has many advantages, including high hardness, relatively low refractive index, excellent chemical stability, low price and commercial availability from different sources …”

Triazole-forming waterborne polyurethane composites fabricated with silane coupling agent functionalized nano-silica

“…It is well known that surface roughness and surface energy affect the WCA. Therefore, the linkage of ASiFS and the WPU matrix changed the surface characteristics of the hybrid materials and led to a lower surface energy [32,33]. However, it also can be seen from Fig.…”

Novel vapor-grown carbon nanofiber/epoxy shape memory nanocomposites prepared via latex technology

“…This finding may be attributed to the addition of emulsifiers acting as a plasticizer in the preparation of the water-borne epoxy resin. However, the yield strength of the pristine epoxy resin is twice as higher as that of SM polyurethanes at 25 1C [11,12].…”