Contribution of Linear Guest and Structural Pendant Chains to Relaxational Dynamics in Model Polymer Networks Probed by Time-Domain 1H NMR
| Autor: | Rodolfo H. Acosta, Florencia Campise, Daniel A. Vega, Leandro E. Roth, Marcelo A. Villar, Enrique M. Vallés, Gustavo A. Monti |
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| Rok vydání: | 2015 |
| Předmět: |
chemistry.chemical_classification
Millisecond Materials science Polymers and Plastics Organic Chemistry Relaxation (NMR) Nanotechnology 02 engineering and technology Polymer 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Inorganic Chemistry Superposition principle Orders of magnitude (time) chemistry Chemical physics Materials Chemistry medicine Proton NMR Time domain Swelling medicine.symptom 0210 nano-technology |
| Zdroj: | Macromolecules. 49:387-394 |
| ISSN: | 1520-5835 0024-9297 |
| DOI: | 10.1021/acs.macromol.5b01806 |
| Popis: | A series of end-linked polymer networks with varying contents of linear guest chains were investigated through swelling and time-domain NMR temperature dependent experiments. Taking advantage of the thermorheological simplicity of polydimethylsiloxane polymers, time–temperature superposition (TTS) was employed to expand the characteristic time scales of NMR exploration by about 2 orders of magnitude. A comparison between swelling data and tube model predictions reveals that NMR captures the dominant features of the equilibrium and dynamic properties of defects trapped in slightly cross-linked, entanglement-dominated polymer networks. As high-temperature experiments ensures a complete relaxation of the guest linear chains on the millisecond time scale of the NMR experiments, an accurate description of the network architecture can be provided. Contents of guest chains determined by NMR were found to agree within a 1 wt % accuracy with data of swelling experiments. |
| Databáze: | OpenAIRE |
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