Polyhedral oligomeric silsesquioxanes preparation

Li Wanwan, Liu Feng, Wei Liuhe, and Zhao Tong. Allylated novolac/4, 4 -bismaleimido-diphenylmethane resin containing polyhedral oligomeric silsesquioxane Preparation, morphology and thermal stability. J. Appl. Polym. Sci. 104 no. 6 (2007) 3903-3908. 

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]. 

PDMS nanocomposites with layered mica-type silicates were also reported.374 A two-step sol-gel process of the in situ precipitation of silica led to the development of siloxane-based nanocomposites with particularly high transparencies.3 5 Some unusual nanocomposites prepared by threading polymer chains through zeolites, mesoporous silica, or silica nanotubes were reviewed.3 6 Poly(4-vinylpyridine) nanocross-linked by octa(propylglycidyl ether) polyhedral oligomeric silsesquioxane was reported.377... 

Lai et al. (3) prepared reactive polyhedral oligomeric silsesquioxane derivatives,... 

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],... 

Crosslinkable polyhedral oligomeric silsesquioxane, (11), prepared by Jin [2] were used as dental composites in restorative applications, especially in crown and bridge materials. 

Nanocomposites from (poly[2,2 -(p-oxidiphen-ylene)-5,5 -bibenzimidazole]) and polyhedral oligomeric silsesquioxane (POSS) with a pendant phenyl group have been prepared by an in situ polymerization of 4,4 -dicarboxydiphenyl ether and 3,3 -diaminobenzidine in the presence of POSS [21]. The PBI chains were successfully attached to the phenyl group of the POSS by aFriedel-Crafls reaction. 

FIGURE 34.2. Some of the functionalities that can be prepared from POSS-trisilanol precursors [1]. (Applied Organometallic Chemistry, 12, Schwab, J. J. and Lichtenhan, J. D., Polyhedral Oligomeric Silsesquioxane (POSS)-based Polymers, pp. 707-713, Copyright (1998), John Wiley and Sons Ltd., New York. Reproduced with permission.)... 

Choi, J.H., Jung, C.H., Kang, D.W., Hwang, I.T., Choi, J.H. Preparation and characterization of crosslinked poly( -caprolactone)/polyhedral oligomeric silsesquioxane nanocomposites by electron beam irradiation. Nucl. Instrum. Meth. Phys. Res. B 287, 141-147 (2012)... 

Liu, L. Tian, M. Zhang, W. Zhang, L. Mark, J. E., Crystallization and Morphology Study of Polyhedral Oligomeric Silsesquioxane (POSS)/Polysiloxane Elastomer Composites Prepared by Melt Blending. Polymer 2007,48, 3201-3212. 

Figure 3.6 shows the thermal stability of organoclay prepared with aminopropylisobutyl polyhedral oligomeric silsesquioxane (POSS) and cetylpyridinium chloride (CPC) [31]. 

At present, clays are by large the most investigated nanofillers in flame retar-dancy. In this chapter we focus on thermoset nanocomposites based on layered silicates and a lately emerging class of layered crystals known as layered double hydroxides G DHs). The use of polyhedral oligomeric silsesquioxanes and nanotubes nanocomposites is discussed in Chapter 10. The preparation of thermoset nanocomposites based on spherical nanosilica is also reported in the hterature. It is shown that while being heated in the nanocomposite, nanosilica, migrates to the surface of the material, due to the relatively low surface potential energy... 

Another strategy for moisture-adaptive shape-memory polymer preparation is to use water soluble segments as a soft segment to prepare SMPUs. Preparation is by polyhedral oligomeric silsesquioxane (POSS) molecules and poly(ethylene glycol) that act as the hydrophobic and hydrophilic groups. The POSS groups... 

Liu, L., Tian, M., Zhang, W., Zhang, L., and Mark, J.E. (2007) Crystallization and morphology study of polyhedral oligomeric silsesquioxane (POSS)/ polysiloxane elastomer composites prepared by melt blending. Polymer, 48, 3201-3212. 

Chapter 5 is a review of polyhedral oligomeric silsesquioxanes (POSS), hybrid POSS-organic copolymers, and POSS resin nanocomposites. Although silsesquioxanes have been known since tiie 1960s, only recently, through controlled synthesis and purification, have their structure and unique properties been determined and their useful applications been explored. This chapter is complemented by a discussion of the synthesis and properties of silica- and silsesquioxanes-containing polymer nanohybrids in Chapter 6. Chapter 7 involves a review of the preparation and characterization of siloxane-based polyviologens, polyurethanes, and divinylben-zene elastomers. 

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