Epoxy networks modified by a new class of oligomeric silsesquioxanes bearing multiple intramolecular rings formed through Si-O-C bonds
A new class of silsesquioxane (SSO), containing species with two to nine Si atoms bearing multiple intramolecular rings formed through Si-O-C bonds, was synthesized as a glassy powder. It was characterized by UV-MALDI-TOF MS, 29Si NMR and FT IR. Solutions containing different amounts of SSO in the d...
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2004
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14387492_v289_n4_p315_DellErba http://hdl.handle.net/20.500.12110/paper_14387492_v289_n4_p315_DellErba |
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paper:paper_14387492_v289_n4_p315_DellErba2023-06-08T16:15:54Z Epoxy networks modified by a new class of oligomeric silsesquioxanes bearing multiple intramolecular rings formed through Si-O-C bonds Epoxy Heteroatom-containing polymers Networks Polysiloxanes Silsesquioxane Thermosets Chemical bonds Elastic moduli Fourier transform infrared spectroscopy Glass transition Homopolymerization Nuclear magnetic resonance Phase separation Synthesis (chemical) Epoxy networks Glassy powders Silsesquioxane (SSO) Silicon 2,2 bis(4 glycidyloxyphenyl)propane 4 dimethylaminopyridine 4,4' isopropylidenediphenol epoxide silicon derivative silsesquioxane unclassified drug article cross linking glass transition temperature infrared spectroscopy matrix assisted laser desorption ionization time of flight mass spectrometry nuclear magnetic resonance spectroscopy synthesis young modulus A new class of silsesquioxane (SSO), containing species with two to nine Si atoms bearing multiple intramolecular rings formed through Si-O-C bonds, was synthesized as a glassy powder. It was characterized by UV-MALDI-TOF MS, 29Si NMR and FT IR. Solutions containing different amounts of SSO in the diglycidyl ether of bisphenol A (DGEBA), were homopolymerized in the presence of (4-dimethylamino)pyridine (DMAP) as initiator, leading to SSO-modified epoxy networks. SSO species were covalently bonded to the epoxy network without any evidence of phase separation. The SSO addition provoked an increase in the elastic modulus in the glassy state explained by an increase in the cohesive energy density. The SSO addition gave also place to an increase in the intensity of tan δ and a decrease in both the glass transition temperature and the elastic modulus in the rubbery state. This was explained by a decrease in crosslink density associated with the flexibility of SSO structures. DMAP was much more effective than other usual initiators (like benzyldimethylamine, BDMA), in increasing the crosslink density of the resulting epoxy network. This led to high values of the glass transition temperature and the elastic modulus in the rubbery state. 2004 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14387492_v289_n4_p315_DellErba http://hdl.handle.net/20.500.12110/paper_14387492_v289_n4_p315_DellErba |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Epoxy Heteroatom-containing polymers Networks Polysiloxanes Silsesquioxane Thermosets Chemical bonds Elastic moduli Fourier transform infrared spectroscopy Glass transition Homopolymerization Nuclear magnetic resonance Phase separation Synthesis (chemical) Epoxy networks Glassy powders Silsesquioxane (SSO) Silicon 2,2 bis(4 glycidyloxyphenyl)propane 4 dimethylaminopyridine 4,4' isopropylidenediphenol epoxide silicon derivative silsesquioxane unclassified drug article cross linking glass transition temperature infrared spectroscopy matrix assisted laser desorption ionization time of flight mass spectrometry nuclear magnetic resonance spectroscopy synthesis young modulus |
| spellingShingle |
Epoxy Heteroatom-containing polymers Networks Polysiloxanes Silsesquioxane Thermosets Chemical bonds Elastic moduli Fourier transform infrared spectroscopy Glass transition Homopolymerization Nuclear magnetic resonance Phase separation Synthesis (chemical) Epoxy networks Glassy powders Silsesquioxane (SSO) Silicon 2,2 bis(4 glycidyloxyphenyl)propane 4 dimethylaminopyridine 4,4' isopropylidenediphenol epoxide silicon derivative silsesquioxane unclassified drug article cross linking glass transition temperature infrared spectroscopy matrix assisted laser desorption ionization time of flight mass spectrometry nuclear magnetic resonance spectroscopy synthesis young modulus Epoxy networks modified by a new class of oligomeric silsesquioxanes bearing multiple intramolecular rings formed through Si-O-C bonds |
| topic_facet |
Epoxy Heteroatom-containing polymers Networks Polysiloxanes Silsesquioxane Thermosets Chemical bonds Elastic moduli Fourier transform infrared spectroscopy Glass transition Homopolymerization Nuclear magnetic resonance Phase separation Synthesis (chemical) Epoxy networks Glassy powders Silsesquioxane (SSO) Silicon 2,2 bis(4 glycidyloxyphenyl)propane 4 dimethylaminopyridine 4,4' isopropylidenediphenol epoxide silicon derivative silsesquioxane unclassified drug article cross linking glass transition temperature infrared spectroscopy matrix assisted laser desorption ionization time of flight mass spectrometry nuclear magnetic resonance spectroscopy synthesis young modulus |
| description |
A new class of silsesquioxane (SSO), containing species with two to nine Si atoms bearing multiple intramolecular rings formed through Si-O-C bonds, was synthesized as a glassy powder. It was characterized by UV-MALDI-TOF MS, 29Si NMR and FT IR. Solutions containing different amounts of SSO in the diglycidyl ether of bisphenol A (DGEBA), were homopolymerized in the presence of (4-dimethylamino)pyridine (DMAP) as initiator, leading to SSO-modified epoxy networks. SSO species were covalently bonded to the epoxy network without any evidence of phase separation. The SSO addition provoked an increase in the elastic modulus in the glassy state explained by an increase in the cohesive energy density. The SSO addition gave also place to an increase in the intensity of tan δ and a decrease in both the glass transition temperature and the elastic modulus in the rubbery state. This was explained by a decrease in crosslink density associated with the flexibility of SSO structures. DMAP was much more effective than other usual initiators (like benzyldimethylamine, BDMA), in increasing the crosslink density of the resulting epoxy network. This led to high values of the glass transition temperature and the elastic modulus in the rubbery state. |
| title |
Epoxy networks modified by a new class of oligomeric silsesquioxanes bearing multiple intramolecular rings formed through Si-O-C bonds |
| title_short |
Epoxy networks modified by a new class of oligomeric silsesquioxanes bearing multiple intramolecular rings formed through Si-O-C bonds |
| title_full |
Epoxy networks modified by a new class of oligomeric silsesquioxanes bearing multiple intramolecular rings formed through Si-O-C bonds |
| title_fullStr |
Epoxy networks modified by a new class of oligomeric silsesquioxanes bearing multiple intramolecular rings formed through Si-O-C bonds |
| title_full_unstemmed |
Epoxy networks modified by a new class of oligomeric silsesquioxanes bearing multiple intramolecular rings formed through Si-O-C bonds |
| title_sort |
epoxy networks modified by a new class of oligomeric silsesquioxanes bearing multiple intramolecular rings formed through si-o-c bonds |
| publishDate |
2004 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14387492_v289_n4_p315_DellErba http://hdl.handle.net/20.500.12110/paper_14387492_v289_n4_p315_DellErba |
| _version_ |
1768541671480360960 |