Influence of the melt extrusion process on the mechanical behavior and the thermal properties of ethylene vinyl alcohol copolymer by applying the successive self-nucleation and annealing thermal fractionation
Ethylene vinyl alcohol copolymer was processed three times in a twin-screw extrusion pilot plant in order to reproduce the processing steps required to obtain EVOH nanocomposites. Thin film of the extruded EVOH was prepared by using a cast-film line. The melt flow index and rheological behavior of t...
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2021 |
| 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:2117/366978 |
| Acceso en línea: | https://hdl.handle.net/2117/366978 https://dx.doi.org/10.1007/s12221-021-0386-2 |
| Access Level: | acceso abierto |
| Palabra clave: | Copolymers Copolímers Àrees temàtiques de la UPC::Enginyeria dels materials |
| Sumario: | Ethylene vinyl alcohol copolymer was processed three times in a twin-screw extrusion pilot plant in order to reproduce the processing steps required to obtain EVOH nanocomposites. Thin film of the extruded EVOH was prepared by using a cast-film line. The melt flow index and rheological behavior of the film were determined. Viscoelastic parameters were evaluated in a dynamic mechanical testing instrument that revealed the presence of two signals, one attributed to the glass transition temperature and the other one related to the structural modifications associated to interlamellar separation. Thermal properties were evaluated in a differential scanning calorimetry by applying a standard evaluation and successive self-nucleation and annealing approach, finding structural modifications influenced by the melt extrusion process, although the overall percentage of crystallinity degree remains similar. Based on the structural results, the mechanical properties were evaluated considering the ethylene content and resulting on distinct mechanical behavior. Lower ethylene content allows the chain orientation induced during the processing of the film that favors the mechanical performance. Higher ethylene content promotes different deformation mechanisms and a relevant ductility |
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