Aldehyde-Assisted Alkoxysilane Condensation to Form Siloxane Bond: A New Process for Curing Alkoxy-Functional Silicone Resins
Abstract
:1. Introduction
2. Results and Discussion
2.1. Study of the Curing Process of the Alkoxy-Functional Siloxane Resins
2.2. Model Study of the SiOR + SiOR Condensation Reaction Catalyzed by Cp*Ge+ B(C6F5)4−
2.3. Study of the SiOR + SiOR Condensation Reaction in the Presence of Paraldehyde Catalyzed by Cp*Ge BArF4
2.4. Testing Decomposition of Dialkyl Acetal in the Presence of Cp*Ge+ B(C6F5)4−
2.5. Mechanism of the De-Alkoxylation Reaction in the Presence of Aldehyde—DFT Calculations
3. Materials and Methods
3.1. Materials
3.2. Synthesis of Alkoxysilanes and Siloxanes
3.3. NMR Spectroscopy
3.4. Gas Chromatography–Mass Spectrometry (GC/MS)
3.5. Gas Chromatography
3.6. Study of the Condensation Cure of the Alkoxy-Functional Silicone Resins
3.7. Study of the Condensation of Model Alkoxysilanes in the Presence of Propionaldehyde
3.8. Theoretical Methods
4. Conclusions
Supplementary Materials
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Acknowledgments
Conflicts of Interest
References
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Experiment # | Atmosphere | Propionaldehyde mol% vs. SiOMe | Time to Gel |
---|---|---|---|
1 | Dry nitrogen | none | Liquid after 1 week |
2 | Air, RH = 74% | none | 8 h |
3 | Nitrogen, RH = 90% | none | 4 h |
4 | Dry oxygen | none | Liquid after 1 week |
5 | Dry nitrogen | 5 | Liquid after 1 week |
6 | Dry nitrogen | 14 | 1.5 h |
7 | Dry nitrogen | 18 | 20 min |
8 | Dry nitrogen | 24 | 10 min |
ΔH | ΔG | |
---|---|---|
CpGe+---Nu | ||
EtCHO | −16.6 | −9.1 |
MeOSiMe3 | −18.9 | −9.7 |
Me3SiOSiMe3 | −17.5 | −5.3 |
Cp*Ge+---Nu | ||
EtCHO | −12.7 | −4.9 |
MeOSiMe3 | −14.0 | −4.0 |
Me3SiOSiMe3 | −12.6 | −0.7 |
ΔHrel | ΔGrel | |
---|---|---|
CpGe+ + EtCHO + MeOSiMe3 | 0 | 0 |
CpGe+–EtCHO + MeOSiMe3 | −16.6 | −9.1 |
CpGe+–MeOSiMe3 + EtCHO | −18.9 | −9.7 |
I | −30.7 | −10.0 |
I-TS | −8.5 | 16.7 |
II | −26.1 | −2.6 |
III | −31.6 | −8.0 |
CpGe+ + EtCH(OMe)(OSiMe3) | −8.3 | 5.3 |
IV-TS | −30.9 | 4.6 |
V | −29.8 | 5.9 |
VI | −19.7 | 5.2 |
VI-TS | −24.6 | 14.8 |
VII | −46.5 | −9.5 |
VIII, CpGe+–EtCHO + Me3SiOSiMe3 | −19.4 | −4.6 |
CpGe+ + EtCH(OMe)2 + Me3SiOSiMe3 | −14.9 | −1.6 |
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Rubinsztajn, S.; Mizerska, U.; Kurjata, J.; Kwiatkowska, M.; Cypryk, M. Aldehyde-Assisted Alkoxysilane Condensation to Form Siloxane Bond: A New Process for Curing Alkoxy-Functional Silicone Resins. Molecules 2025, 30, 714. https://doi.org/10.3390/molecules30030714
Rubinsztajn S, Mizerska U, Kurjata J, Kwiatkowska M, Cypryk M. Aldehyde-Assisted Alkoxysilane Condensation to Form Siloxane Bond: A New Process for Curing Alkoxy-Functional Silicone Resins. Molecules. 2025; 30(3):714. https://doi.org/10.3390/molecules30030714
Chicago/Turabian StyleRubinsztajn, Sławomir, Urszula Mizerska, Jan Kurjata, Małgorzata Kwiatkowska, and Marek Cypryk. 2025. "Aldehyde-Assisted Alkoxysilane Condensation to Form Siloxane Bond: A New Process for Curing Alkoxy-Functional Silicone Resins" Molecules 30, no. 3: 714. https://doi.org/10.3390/molecules30030714
APA StyleRubinsztajn, S., Mizerska, U., Kurjata, J., Kwiatkowska, M., & Cypryk, M. (2025). Aldehyde-Assisted Alkoxysilane Condensation to Form Siloxane Bond: A New Process for Curing Alkoxy-Functional Silicone Resins. Molecules, 30(3), 714. https://doi.org/10.3390/molecules30030714