Polyhedral oligosilsesquioxanes and their homo derivatives

Воронков, М. Г.; Lavrent'yev, Vladimir I.

doi:10.1007/3-540-11345-2_12

Cited by 476 publications

(385 citation statements)

References 33 publications

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“…1 They show a cube-shaped Si 8 O 12 unit as illustrated in Scheme 1. During the past few years an increasing number of organo-or organometallo-functionalized silasesquioxanes have become available.…”

Section: Introductionmentioning

confidence: 99%

Vibrational Structure of Monosubstituted Octahydrosilasesquioxanes

Marcolli

Calzaferri

1997

J. Phys. Chem. B

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The IR and Raman spectra of the monosubstituted hydrosilasesquioxanes RH 7 Si 8 O 12 , R ) Co(CO) 4 , Ph, CHdCHPh, and CH 2 CH 2 Ph, have been analyzed by spectral correlation and a normal coordinate analysis. They were treated as a superposition of the spectra of the siloxane cage and the substituent. 12 , contributing each a case of an Si-C phenyl , Si-C vinyl , and Si-C alkyl bond, respectively. The force constants of the different Si-C bonds were related to the Si-C bond orders and extrapolated for Si-C acetyl of (PhCtCH)H 7 Si 8 O 12 , which is not yet available. The inorganic-substituted hydrosilasesquioxane [Co(CO) 4 (H 7 Si 8 O 12 )] could be analyzed the same way as the organic-substituted compounds and showed a similar pattern for the siloxane cage vibrations. Although most spectral features of the siloxane cages could be understood assuming a local C 3V symmetry, vibrations indicating a lower symmetry occurred in all monosubstituted compounds and could be attributed to vibrational coupling with modes of the substituent. Especially the totally symmetric ring-opening vibration at 456 cm -1 in H 8 Si 8 O 12 showed a specific dependence on the different substituents.

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Section: Introductionmentioning

confidence: 99%

Vibrational Structure of Monosubstituted Octahydrosilasesquioxanes

Marcolli

Calzaferri

1997

J. Phys. Chem. B

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“…29 Si NMR: showed two peaks at -2.89 ppm (H-Si-CH 3 ) and -108.69 ppm (Si-O 4 ). Synthesis of 1,3,5,7,9,11,13,15-octa[dimethylsiloxypropylglycidylether] pentaciclo [9.5.1.1 3,9 .1 5,15 .1 7,13 ] octasilsesquioxane (ODPG) The synthesis of ODPG followed published procedures [19,20,28], as it is described below. A schematic representation of this reaction is showed in the Fig.…”

Section: Synthesis Ofmentioning

confidence: 99%

“…To overcome these drawbacks, many types of polymer-filler composites have been developed, in which the epoxy resins are reinforced with modifying agents, such as fillers, polyhedral oligosilsesquioxanes, dendrimers etc. [8][9][10][11][12][13][14][15][16][17][18].…”

Section: Introductionmentioning

confidence: 99%

“…In the POSS, the cubic silica core is a "hard particle" rigid with 0.53 nm diameter and a spherical radius of 1-3 nm including peripheral organic units [14][15][16][17][18].…”

Section: Introductionmentioning

confidence: 99%

“…29 Si NMR: showed one peak at -99.4 ppm. 1,3,5,7,9,11,13,15-octa[hydridodimethylsiloxy]pentaciclo [9.5.1.1 3,9 .1 5,15 .1 7,13 [19,20,[25][26][27][28], as it is described below.…”

Section: Introductionmentioning

confidence: 99%

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DEA and DSC study of cubic silsesquioxane epoxy resin nanocomposites

Filho

Aquino

2006

E-Polymers

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Non-isothermal dielectric analysis (DEA) and differential scanning calorimetry (DSC) techniques were used to study the epoxy nanocomposites prepared by reacting 1, 3,5,7,9,11,13,15-octa[dimethylsiloxypropylglycidylether] pentaciclo [9.5.1.1 3,9 .1 5,15 .1 7,13 ] octasilsesquioxane (ODPG) with methylenedianiline (MDA). Loss factor (ε") and activation energy were calculated by DEA. The relationships between the loss factor, the activation energy, the structure of the network, and the mechanical properties were investigated. Activation energies determined by DEA and DSC, heat of polymerization, fracture toughness and tensile modulus show the same profile for mechanical properties with respect to ODPG content.

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Nanoscale reinforcement of polyhedral oligomeric silsesquioxane (POSS) in polyurethane elastomer

et al. 2000

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A unique class of polyurethane (PU) elastomer containing inorganic molecules (polyhedral oligomeric silsesquioxane, POSS) as molecular reinforcement in the hard segment was investigated by means of wide-angle X-ray diffraction (WAXD) and small-angle X-ray scattering (SAXS) techniques. WAXD results indicate that POSS molecules form nanoscale crystals showing distinct re¯ection peaks. The formation of POSS crystals is probably prompted by the microphase separation between solid-like hard segments and rubbery soft segments in PU. The microphase separation of hard and soft segments was observed by SAXS, which shows a long period of 111 A Ê for 34 wt% POSS-PU and 162 A Ê for 21 wt% POSS-PU, and hard segment domains with sizes of about 34 A Ê for both of them. WAXD results from a series of POSS compounds with a corner substituted by a functional group of varying length were compared with POSS-PU, which also con®rms the presence of nanoscale POSS crystals in the polymer matrix.

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Polyhedral oligosilsesquioxanes and their homo derivatives

Cited by 476 publications

References 33 publications

Vibrational Structure of Monosubstituted Octahydrosilasesquioxanes

Vibrational Structure of Monosubstituted Octahydrosilasesquioxanes

DEA and DSC study of cubic silsesquioxane epoxy resin nanocomposites

Nanoscale reinforcement of polyhedral oligomeric silsesquioxane (POSS) in polyurethane elastomer

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