Morphology-Mechanical Performance Relationship at the Micrometrical Level within Molded Polypropylene Obtained with Non-Symmetric Mold Temperature Conditioning
The control of the structural properties of a polymeric material at the micro and nano-metrical scale is strategic to obtaining parts with high performance, durability and free from sudden failures. The characteristic skin-core morphology of injection molded samples is intimately linked to the compl...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-01-01
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| Series: | Polymers |
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| Online Access: | https://www.mdpi.com/2073-4360/13/3/462 |
| _version_ | 1797417291201118208 |
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| author | Sara Liparoti Andrea Sorrentino Vito Speranza |
| author_facet | Sara Liparoti Andrea Sorrentino Vito Speranza |
| author_sort | Sara Liparoti |
| collection | DOAJ |
| description | The control of the structural properties of a polymeric material at the micro and nano-metrical scale is strategic to obtaining parts with high performance, durability and free from sudden failures. The characteristic skin-core morphology of injection molded samples is intimately linked to the complex shear flow, pressure and temperature evolutions experienced by the polymer chains during processing. An accurate analysis of this morphology can allow for the assessment of the quality and confidence of the process. Non-symmetric mold temperature conditions are imposed to produce complex morphologies in polypropylene parts. Morphological and micromechanical characterizations of the samples are used to quantify the effects of the processing conditions on the part performance. Asymmetric distribution of temperatures determines asymmetric distribution of both morphology and mechanical properties. The inhomogeneity degree depends on the time that one side of the cavity experiences high temperatures. The spherulites, which cover the thickest of the parts obtained with high temperatures at one cavity side, show smaller values of elastic modulus than the fibrils. When the polymer molecules experience high temperatures for long periods, the solid-diffusion and the partial melting and recrystallization phenomena determine a better structuring of the molecules with a parallel increase of the elastic modulus. |
| first_indexed | 2024-03-09T06:17:42Z |
| format | Article |
| id | doaj.art-5df55b57950144689ebdc679f99a2e55 |
| institution | Directory Open Access Journal |
| issn | 2073-4360 |
| language | English |
| last_indexed | 2024-03-09T06:17:42Z |
| publishDate | 2021-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Polymers |
| spelling | doaj.art-5df55b57950144689ebdc679f99a2e552023-12-03T11:51:35ZengMDPI AGPolymers2073-43602021-01-0113346210.3390/polym13030462Morphology-Mechanical Performance Relationship at the Micrometrical Level within Molded Polypropylene Obtained with Non-Symmetric Mold Temperature ConditioningSara Liparoti0Andrea Sorrentino1Vito Speranza2Department of Industrial Engineering, University of Salerno, via Giovanni Paolo II, 132, 84084 Fisciano, ItalyInstitute for Polymers, Composites and Biomaterials (IPCB-CNR), Via Previati, 1/C, 23900 Lecco, ItalyDepartment of Industrial Engineering, University of Salerno, via Giovanni Paolo II, 132, 84084 Fisciano, ItalyThe control of the structural properties of a polymeric material at the micro and nano-metrical scale is strategic to obtaining parts with high performance, durability and free from sudden failures. The characteristic skin-core morphology of injection molded samples is intimately linked to the complex shear flow, pressure and temperature evolutions experienced by the polymer chains during processing. An accurate analysis of this morphology can allow for the assessment of the quality and confidence of the process. Non-symmetric mold temperature conditions are imposed to produce complex morphologies in polypropylene parts. Morphological and micromechanical characterizations of the samples are used to quantify the effects of the processing conditions on the part performance. Asymmetric distribution of temperatures determines asymmetric distribution of both morphology and mechanical properties. The inhomogeneity degree depends on the time that one side of the cavity experiences high temperatures. The spherulites, which cover the thickest of the parts obtained with high temperatures at one cavity side, show smaller values of elastic modulus than the fibrils. When the polymer molecules experience high temperatures for long periods, the solid-diffusion and the partial melting and recrystallization phenomena determine a better structuring of the molecules with a parallel increase of the elastic modulus.https://www.mdpi.com/2073-4360/13/3/462nano-indentationpolymer morphologymechanical propertiespolymer processing |
| spellingShingle | Sara Liparoti Andrea Sorrentino Vito Speranza Morphology-Mechanical Performance Relationship at the Micrometrical Level within Molded Polypropylene Obtained with Non-Symmetric Mold Temperature Conditioning Polymers nano-indentation polymer morphology mechanical properties polymer processing |
| title | Morphology-Mechanical Performance Relationship at the Micrometrical Level within Molded Polypropylene Obtained with Non-Symmetric Mold Temperature Conditioning |
| title_full | Morphology-Mechanical Performance Relationship at the Micrometrical Level within Molded Polypropylene Obtained with Non-Symmetric Mold Temperature Conditioning |
| title_fullStr | Morphology-Mechanical Performance Relationship at the Micrometrical Level within Molded Polypropylene Obtained with Non-Symmetric Mold Temperature Conditioning |
| title_full_unstemmed | Morphology-Mechanical Performance Relationship at the Micrometrical Level within Molded Polypropylene Obtained with Non-Symmetric Mold Temperature Conditioning |
| title_short | Morphology-Mechanical Performance Relationship at the Micrometrical Level within Molded Polypropylene Obtained with Non-Symmetric Mold Temperature Conditioning |
| title_sort | morphology mechanical performance relationship at the micrometrical level within molded polypropylene obtained with non symmetric mold temperature conditioning |
| topic | nano-indentation polymer morphology mechanical properties polymer processing |
| url | https://www.mdpi.com/2073-4360/13/3/462 |
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