Polyhedral oligomeric silsesquioxanes properties

Nanocomposite based on polyurethane (PU) is prepared using silica, clay, and Polyhedral Oligomeric Silsesquioxane (POSS). Preparation, characterization, mechanical and barrier properties, morphology, and effect of processing conditions have been reported on polyurethane-based nanocomposites [72,73]. 

Polyhedral oligomeric silsesquioxane (POSS) has been extensively studied as starting substrate to construct nanocomposites with precise control of nanoarchitecture and properties. Octahedral derivatives are the most representative ones of this family. It was reported that the HRP-catalyzed conjugation of catechin on amine-substituted octahedral silsesquioxane amplified the beneficial physiological property of flavonoids. The POSS-catechin conjugate exhibited great... 

Polyhedral oligomeric silsesquioxanes (POSS) are known molecules having various structures [1] as seen in Fig. 1. However double-decker shaped silsesquioxane has not been obtained. POSS is an interesting class of monomers for the preparation of silicon-based polymers. In recent years, silsesquioxane-based polymers have received much attention because of their useful properties, which include heat resistance, mechanical stability, low dielectric constant, etc. [2, 3],... 

The polyhedral oligomeric silsesquioxane structure affects the rheological and cure characteristics but was found to have no discernible influence on the properties in the cured state. 

Broadband dielectric spectroscopy is a powerful tool to investigate polymeric systems (see [38]) including polymer-based nanocomposites with different nanofillers like silica [39], polyhedral oligomeric silsesquioxane (POSS) [40-42], and layered silica systems [43-47] just to mention a few. Recently, this method was applied to study the behavior of nanocomposites based on polyethylene and Al-Mg LDH (AlMg-LDH) [48]. The properties of nanocomposites are related to the small size of the filler and its dispersion on the nanometer scale. Besides this, the interfacial area between the nanoparticles and the matrix is crucial for the properties of nanocomposites. Because of the high surface-to-volume ratio of the nanoparticles, the volume fraction of the interfacial area is high. For polyolefin systems, this interfacial area might be accessible by dielectric spectroscopy because polyolefins are nonpolar and, therefore, the polymeric matrix is dielectrically invisible [48]. 

Zhang, Y., Lee, S., Yoonessi, M., Liang, K., Pittman, C.U. Phenolic resin-trisilanolphenyl polyhedral oligomeric silsesquioxane (POSS) hybrid nanocomposites structure and properties. Polymer 47, 2984-2996 (2006)... 

Ryu, H.-S. Kim, D.-G. Lee, J.-C., Polysiloxanes Containing Polyhedral Oligomeric Silsesquioxane Groups in the Side Chains Synthesis and Properties. Polymer 2010,51, 2296-2304. 

Mabry, J. M. Vij, A. Viers, B. D. Grabow, W. W. Marchant, D. lacono, S. C. Ruth, P. N. Vij, I., Hydrophobic Silsesquioxane Nanoparticles and Nanocomposite Surfaces Overview of the Synthesis and Properties of Fluorinated Polyhedral Oligomeric Silsesquioxane (POSS) and Fluorinated POSS Nanocomposites. In Science and Technology of Silicones and Silicone-Modified Materials, Clarson, S. J. Fitzgerald, J. J. Owen, M. J. Smith, S. D. Van Dyke, M. E., Eds. American Chemical Society Washington, DC, 2007 Vol. 964,... 

Enhancing Mechanical Properties of SMPs by Incorporation of Polyhedral Oligomeric Silsesquioxanes (POSS)... 

A non-biodegradable nanocomposite based on polyhedral oligomeric silsesquioxane nanocages with poly(carbonate urethane) has been developed (33). A good ceU-compatibility and antithrombo-genic properties have been noticed. 

Another important area of research in biocompatible SMPINCs is the use of polyhedral oligomeric silsesquioxanes (POSS). In recent studies, these POSS cages primarily served as anchor sites for PCL chains to make organosilica SMPINCs with a wide variety of properties, ranging from triple-shape POSS/PCL networks [116], dynamic microscale surface features [117], ultrasoft networks post-transition... 

C.M. Leu, Y.T. Chang, K.H. Wei, Synthesis and dielectric properties of polyimide-tethered polyhedral oligomeric silsesquioxane (POSS) nanocomposites via POSS-diamine, Macromolecules 36 (24) (2003)9122-9127. 

Ahmed M, Ghanbari H, Cousins BG, Hamilton G, Seifafian AM. Small cahbre polyhedral oligomeric silsesquioxane nanocomposite cardiovascular grafts influence of porosity on the structure, haemocompatibility and mechanical properties. Acta Biomater 2011 7 3857-67. 

Wang Zheng, Wu Wei, Zhong Yuhua, Ruan Mingzhu, and Hui Lin Lin. Flame-retardant materials based on phosphorus-containing polyhedral oligomeric silsesquioxane and bismaleimide/DBA with improved thermal resistance and dielectric properties. J. Appl. Polym. Sci. 132 no. 9 (2015) 41545-41555. 

Zeng Li, Liang Guozheng, Gu Aijuan, Yuan Li, Zhuo Dongxian, and Hu Jiang-Tao. High performance hybrids based on a novel incompletely condensed polyhedral oligomeric silsesquioxane and bismaleimide resin with improved thermal and dielectric properties. J. Mater. Sci. 47 no. 6 (2012) 2548-2558. 

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