Silsesquioxane-based polymer

Lichtenhan, J. D. Silsesquioxane-Based Polymers. In Polymeric Materials Encyclopedia-, Salamone, J. C., Ed. GRG Press Boca Raton, 1996 ... 

Silsesquioxane-Based Polymers Synthesis of Phenylsilsesquioxanes with Double-Decker Structure and Their Polymers... 

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],... 

Synthesis of Silsesquioxane Based Polymers and Property of Their Polymers... 

We have obtained silsesquioxane-based polymer (HS-Polymer) by using the hydro-silylation reaction of vinyl-functionalized macromonomer (DD-2V) with some SiH-functionalized siloxanes (Scheme 4). 

Lichtenhan JD (1995) Polyhedral oligomeric silsesquioxanes - building-blocks for silsesquioxane-based polymers and hybrid materials. Conunents Inorg Chem 17(2) 115-130. doi 10.1080/02603599508035785... 

Liehtenhan, J. D., Polyhedral oligomerie silsesquioxanes building bloeks for silsesquioxane-based polymers and hybrid materials, Comments Inorg. Chem., 29, 115 (1995). 

Schwab J J, Lichtenhan J D. (1998) Polyhedral oligomeric silsesquioxane (POSS)-based polymers. Appl Organomet Chem 12 707-713. 

Monomethacrylate-functionalized POSS reagents are capable of being polymerized into novel linear silsesquioxane-based materials. Efforts to copolymerize these methacrylate-functionalized POSS with other acryhc comonomers have been successful [96,112]. In a typical polymer synthesis, a 0.5 M toluene solution of macromonomer was prepared, to which 2,2 -azobis(iso-butyronitrile) (AIBN) based on macromonomer was added from a stock solution. The clear solution was heated at 60 °C for 24 h and then precipitated into methanol. Further purification was performed by reprecipitation from toluene into methanol to yield white powder. 

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.)... 

Simionescu, B., Olaru, M., Aflori, M., and Cotofana, C. Silsesquioxane-based hybrid nanocomposite with self-assembling properties for porous limestones conservation. High Perform. Polym. 22 no. 1 (2010) 42-55. 

The synthesis and properties of star polymers and dendrimers functionalized with ferrocene units has attracted a great deal of attention. The synthesis of high-generation dendrimers functionalized with chiral ferrocenyl units in their structures has been reported. The chiroptical properties of this class of dendrimer was dependent on the number of ferrocenyl groups and their chemical environment, but not on their position within the dendrimer. Deschenaux has reported the synthesis of hquid crystalline ferrocene-based polymers prossessing an enantiotropic smectic A phase. Ferrocene-functionahzed cyclic siloxane (29) and silsesquioxane branched polymers have also been reported. A hyperbranched polymer with a cubic silsesquioxane core was used to mediate the electrocatalytic oxidation of ascorbic acid. 

Polyhedral Oligomeric Silsesquioxanes with Controlled Structure Formation and Application in New Si-Based Polymer Systems... 

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. 

Dintcheva, N.T., Morici, E., Arrigo, R., La Mantia, F.P., Malatesta, V., Schwab, J.J. UV-stabilisation of polystyrene-based nanocomposites provided by polyhedral oligomeric silsesquioxanes (POSS). Polym. Degrad. Stab. 97, 2313-2322 (2012)... 

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... 

Perfluoroalkyl groups are also introduced into block copolymers with methacrylates, acrylates, and styrene (B-46 to B-53), which can be synthesized in scCC>2 or in the bulk.95,315 Amphiphilic block copolymers based on glycopolymer segments (B-54 and B-55) are synthesized by copper-catalyzed polymerizations.321,322 Comonomers with a polyhedral oligomeric silsesquioxane unit afforded hybrid polymers between organic and inorganic components (B-56 and B-57).326... 

---