Chavez, Ricardo ; Ionescu, Emanuel ; Balan, Corneliu ; Fasel, Claudia ; Riedel, Ralf (2011)
Effect of ambient atmosphere on crosslinking of polysilazanes.
In: Journal of Applied Polymer Science, 119 (2)
doi: 10.1002/app.32777
Article, Bibliographie
Abstract
The influence of ambient atmosphere on the crosslinking process of two commercially available polysilazanes with different molecular units in the backbone structure (one polysilazane with and one without urea units) was studied at different temperatures using oscillatory rheometry under isothermal conditions. The measurements were performed using cone/plate, plate/plate, and Couette geometries to assess the influence of the contact surface of the samples with air on their crosslinking behavior. The crosslinking process of the investigated polysilazanes in ambient atmosphere was found to occur faster than that in inert atmosphere. DSC and FTIR-spectroscopic investigations indicate that hydrolysis and polycondensation processes occur in both polysilazanes when crosslinked in air. Interestingly, the effect of moisture was found to be more pronounced in the case of the urea derivative. The evolution of the measured complex viscosity and dynamic moduli supported this finding. Furthermore, the variation of the time derivative of complex viscosity (dη*/dt) emphasizes structural changes during crosslinking of the samples which were ascribed to their contact with the ambient atmosphere. This study emphasizes the high potential of rheometry in investigating the crosslinking behavior of polymers in inert and ambient atmosphere. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
| Item Type: | Article |
|---|---|
| Erschienen: | 2011 |
| Creators: | Chavez, Ricardo ; Ionescu, Emanuel ; Balan, Corneliu ; Fasel, Claudia ; Riedel, Ralf |
| Type of entry: | Bibliographie |
| Title: | Effect of ambient atmosphere on crosslinking of polysilazanes |
| Language: | English |
| Date: | 15 January 2011 |
| Publisher: | Wiley |
| Journal or Publication Title: | Journal of Applied Polymer Science |
| Volume of the journal: | 119 |
| Issue Number: | 2 |
| DOI: | 10.1002/app.32777 |
| Abstract: | The influence of ambient atmosphere on the crosslinking process of two commercially available polysilazanes with different molecular units in the backbone structure (one polysilazane with and one without urea units) was studied at different temperatures using oscillatory rheometry under isothermal conditions. The measurements were performed using cone/plate, plate/plate, and Couette geometries to assess the influence of the contact surface of the samples with air on their crosslinking behavior. The crosslinking process of the investigated polysilazanes in ambient atmosphere was found to occur faster than that in inert atmosphere. DSC and FTIR-spectroscopic investigations indicate that hydrolysis and polycondensation processes occur in both polysilazanes when crosslinked in air. Interestingly, the effect of moisture was found to be more pronounced in the case of the urea derivative. The evolution of the measured complex viscosity and dynamic moduli supported this finding. Furthermore, the variation of the time derivative of complex viscosity (dη*/dt) emphasizes structural changes during crosslinking of the samples which were ascribed to their contact with the ambient atmosphere. This study emphasizes the high potential of rheometry in investigating the crosslinking behavior of polymers in inert and ambient atmosphere. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 |
| Uncontrolled Keywords: | polysilazanes, crosslinking, polymer rheology, viscoelastic properties |
| Divisions: | 11 Department of Materials and Earth Sciences > Material Science > Dispersive Solids 11 Department of Materials and Earth Sciences > Material Science 11 Department of Materials and Earth Sciences |
| Date Deposited: | 04 Apr 2012 11:24 |
| Last Modified: | 05 Mar 2013 10:00 |
| PPN: | |
| Funders: | Fonds der Chemischen Industrie |
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