Polyurethanes nanostructures

Figovsky, O. and Shapovalov, L. (2005) Nanostructured Hybrid Nonisocyanate Polyurethane Coatings. Paint and Coatings Industry, 6, 36-44. 

Source Reprinted from O. Figovsky, L. Shapovalov, A. Leykin, O. Birukova, and R. Potesshnikova, Nonisocyanate Polyurethanes Based on Cyclic Carbonates and Nanostructures Composites, J. Scientific Israel Technology Advanced 14, no. 4 (2012) 95—106. With permission. 

Hasegawa M, Ikawa T, Tsuchimori M, Watanabe O, Kawata Y. 2001. Topographical nanostructure patterning on the surface of a thin film of polyurethane containing azobenzene moiety using the optical near field around polystyrene spheres. Macro molecules 34(21) 7471 7476. 

Zia et al. [115] presented that nanostructure and morphological pattern of chitin/bentonite clay based polyurethane bionanocomposites. The clay dispersion within chitin was characterized by both XRD and optical microscopy (OM), which is the most frequently, used and approachable methods to study the structure of nanocomposites. There are one acetamide (-NHCOCH3) group at C-2 position and two (two hydroxy (-OH)) groups at C-3 (C3-OH) and C-6 (C6-OH) positions on chitin chains which can serve as the coordination and reaction sites [95], The crystalline structure of chitin has been reported by many researchers [96],... 

Y. S. Kim, H. H. Lee, P. T. Hammond, High density nanostructure transfer in soft molding using polyurethane acrylate molds and polyelectrolyte multilayers. Nanotechnology, 2003,14,1140. 

This kind of structure is undoubtedly very interesting since it is a nanostructure where nanospheres of acrylic/styrene polymer are embedded in a polyurethane-urea matrix. Such a structure suggests that very specific properties of the film could be obtained if the components of the hybrid were especially selected. 

S. M. Ashraf, S. Ahmad and U. Riaz, Development of sustainable resource-based nanostructured polyaniline/castor oil polyurethane composites , Adv Polym Technol, 2009, 28, 26-31. 

In a similar spirit, but without any consideration about covalent cross-linking, dry nanostructured silicas have been also used for the synthesis of some sifica/polyurethane composites [48]. Silica nanopowders (e.g., finely divided silicas with characteristic dimensions between 10 nm and 100 pm) have been dispersed in various polyurethane sols. After gelation in the presence of these inorganic fillers, the polyurethane-based composites can be considered as superinsulating materials with thermal conductivities lower than 0.020 W/m K. 

Nanostructured polyurethane matrix Cefamandole nafate Bovine serum albumin or poly ally lamine nanoparticles loaded with antibiotic incorporated in a polyurethane matrix Prolonged antimicrobial activity up to 9 days. [28]... 

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