Molecular mobility in hyperbranched polymers and their interaction with an epoxy matrix
The molecular mobility related to the glass transition and secondary relaxations in a hyperbranched polyethyleneimine, HBPEI, and its relaxation behaviour when incorporated into an epoxy resin matrix are investigated by dielectric relaxation spectroscopy (DRS) and dynamic mechanical analysis (DMA)....
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2016 |
| País: | España |
| Institución: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:upcommons.upc.edu:2117/87626 |
| Acceso en línea: | https://hdl.handle.net/2117/87626 https://dx.doi.org/10.3390/ma9030192 |
| Access Level: | acceso abierto |
| Palabra clave: | Nanocomposites (Materials) dielectric relaxation spectroscopy (DRS) differential scanning calorimetry (DSC) dynamic mechanical analysis (DMA) hyperbranched polymer epoxy poly(ethyleneimine) Nanocompostos (Materials) Àrees temàtiques de la UPC::Enginyeria dels materials::Materials compostos |
| Sumario: | The molecular mobility related to the glass transition and secondary relaxations in a hyperbranched polyethyleneimine, HBPEI, and its relaxation behaviour when incorporated into an epoxy resin matrix are investigated by dielectric relaxation spectroscopy (DRS) and dynamic mechanical analysis (DMA). Three systems are analysed: HBPEI, epoxy and an epoxy/HBPEI mixture, denoted ELP. The DRS behaviour is monitored in the ELP system in three stages: prior to curing, during curing, and in the fully cured system. In the stage prior to curing, DRS measurements show three dipolar relaxations: , and , for all systems (HBPEI, epoxy and ELP). The -relaxation for the ELP system deviates significantly from that for HBPEI, but superposes on that for the epoxy resin. The fully cured thermoset displays both - and -relaxations. In DMA measurements, both - and -relaxations are observed in all systems and in both the uncured and fully cured systems, similar to the behaviour identified by DRS. |
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