X-ray Diffraction Study of iPP/clay and iPP/TiO2 Composites Relating to Micromechanical Properties
Composites of isotactic polypropylene with various contents of white clay or titanium dioxide TiO2 were prepared by extrusion molding. The extruded composites were melt-pressed at two different temperatures, and,thereafter, either slowly cooled, or quenched to room temperatures. It is shown that the...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2012 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/79494 |
| Acceso en línea: | http://hdl.handle.net/10261/79494 |
| Access Level: | acceso abierto |
| Palabra clave: | Composites WAXS SAXS Calorimetry Mechanical properties Hardness |
| Sumario: | Composites of isotactic polypropylene with various contents of white clay or titanium dioxide TiO2 were prepared by extrusion molding. The extruded composites were melt-pressed at two different temperatures, and,thereafter, either slowly cooled, or quenched to room temperatures. It is shown that the structure of all the samples, as revealed by wide-angle X-ray scattering and small-angle X-ray scattering (SAXS), depends on the processing conditions. The lack of SAXS maxima in the composites suggests that the presence of the microadditives hinders the stacking of iPP lamellae. Furthermore, the microindentation hardness H in the slowly cooled composites is influenced by the type and amount of the filler used. However, in the quenched samples H depends only on the amount of the filler used, and not on its type. In case of the quenched iPP/clay composites, the relationship between H and the Young’s modulus E is found to be H/E approx. equal to 0.12, in good agreement with Struik’s theoretical predictions of sigma e approx. equal to E/30, in consonance with results previously obtained for a series of polyethylene samples with different morphology. |
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