Molecular weight and tacticity effect on morphological and mechanical properties of Ziegler–Natta catalyzed isotactic polypropylenes
Abstract The morphological and mechanical properties of Ziegler–Natta catalyzed isotactic polypropylenes as influenced by the molecular weight and tacticity was investigated. Polypropylene samples were injection moulded into standard disks with a HAAKE MiniJet II injection moulder at 190 °C and 200...
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| Format: | Article |
| Language: | English |
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Associação Brasileira de Polímeros
2015-01-01
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| Series: | Polímeros |
| Subjects: | |
| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0104-14282015005001109&lng=en&tlng=en |
| _version_ | 1818310849122533376 |
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| author | Ismael Amer Albert van Reenen Touhami Mokrani |
| author_facet | Ismael Amer Albert van Reenen Touhami Mokrani |
| author_sort | Ismael Amer |
| collection | DOAJ |
| description | Abstract The morphological and mechanical properties of Ziegler–Natta catalyzed isotactic polypropylenes as influenced by the molecular weight and tacticity was investigated. Polypropylene samples were injection moulded into standard disks with a HAAKE MiniJet II injection moulder at 190 °C and 200 bar for morphological and mechanical tests. The morphological and mechanical properties of specimens were investigated by means of optical microscope (OM), scanning electron microscopy (SEM), microhardness (MH) and dynamic mechanical analysis (DMA). The samples exhibited a typical α-modification spherulite structure of isotactic polypropylenes crystallized from the melt. It was found that the most important factor affecting the structure and properties of these polymers is the isotacticity content. A clear molecular weight effect was also found for samples with low molecular weights. The microhardness and storage modulus values increased as crystallinity did. Accordingly, isotacticity degree is considered as the main parameter affecting the crystallinity of samples. |
| first_indexed | 2024-12-13T07:52:36Z |
| format | Article |
| id | doaj.art-ffa24305615b4f6d899c072c9ab8c455 |
| institution | Directory Open Access Journal |
| issn | 1678-5169 |
| language | English |
| last_indexed | 2024-12-13T07:52:36Z |
| publishDate | 2015-01-01 |
| publisher | Associação Brasileira de Polímeros |
| record_format | Article |
| series | Polímeros |
| spelling | doaj.art-ffa24305615b4f6d899c072c9ab8c4552022-12-21T23:54:37ZengAssociação Brasileira de PolímerosPolímeros1678-51692015-01-0100010.1590/0104-1428.2158S0104-14282015005001109Molecular weight and tacticity effect on morphological and mechanical properties of Ziegler–Natta catalyzed isotactic polypropylenesIsmael AmerAlbert van ReenenTouhami MokraniAbstract The morphological and mechanical properties of Ziegler–Natta catalyzed isotactic polypropylenes as influenced by the molecular weight and tacticity was investigated. Polypropylene samples were injection moulded into standard disks with a HAAKE MiniJet II injection moulder at 190 °C and 200 bar for morphological and mechanical tests. The morphological and mechanical properties of specimens were investigated by means of optical microscope (OM), scanning electron microscopy (SEM), microhardness (MH) and dynamic mechanical analysis (DMA). The samples exhibited a typical α-modification spherulite structure of isotactic polypropylenes crystallized from the melt. It was found that the most important factor affecting the structure and properties of these polymers is the isotacticity content. A clear molecular weight effect was also found for samples with low molecular weights. The microhardness and storage modulus values increased as crystallinity did. Accordingly, isotacticity degree is considered as the main parameter affecting the crystallinity of samples.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0104-14282015005001109&lng=en&tlng=enmechanical propertymolecular weightmorphological propertypolypropylenetacticity |
| spellingShingle | Ismael Amer Albert van Reenen Touhami Mokrani Molecular weight and tacticity effect on morphological and mechanical properties of Ziegler–Natta catalyzed isotactic polypropylenes Polímeros mechanical property molecular weight morphological property polypropylene tacticity |
| title | Molecular weight and tacticity effect on morphological and mechanical properties of Ziegler–Natta catalyzed isotactic polypropylenes |
| title_full | Molecular weight and tacticity effect on morphological and mechanical properties of Ziegler–Natta catalyzed isotactic polypropylenes |
| title_fullStr | Molecular weight and tacticity effect on morphological and mechanical properties of Ziegler–Natta catalyzed isotactic polypropylenes |
| title_full_unstemmed | Molecular weight and tacticity effect on morphological and mechanical properties of Ziegler–Natta catalyzed isotactic polypropylenes |
| title_short | Molecular weight and tacticity effect on morphological and mechanical properties of Ziegler–Natta catalyzed isotactic polypropylenes |
| title_sort | molecular weight and tacticity effect on morphological and mechanical properties of ziegler natta catalyzed isotactic polypropylenes |
| topic | mechanical property molecular weight morphological property polypropylene tacticity |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0104-14282015005001109&lng=en&tlng=en |
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