Structural Hierarchy of PA6 Macromolecules after Hydrostatic Extrusion
This article presents the influence of severe plastic deformation by hydrostatic extrusion (HE) on the thermal and structural properties of polyamide 6 (PA6). During the hydrostatic extrusion process, a fibrous structure oriented along the extrusion direction is formed, which was visualized during m...
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MDPI AG
2023-04-01
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| Online Access: | https://www.mdpi.com/1996-1944/16/9/3435 |
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| author | Monika Skorupska Mariusz Kulczyk Piotr Denis Dominik Grzęda Anna Czajka Joanna Ryszkowska |
| author_facet | Monika Skorupska Mariusz Kulczyk Piotr Denis Dominik Grzęda Anna Czajka Joanna Ryszkowska |
| author_sort | Monika Skorupska |
| collection | DOAJ |
| description | This article presents the influence of severe plastic deformation by hydrostatic extrusion (HE) on the thermal and structural properties of polyamide 6 (PA6). During the hydrostatic extrusion process, a fibrous structure oriented along the extrusion direction is formed, which was visualized during microscopic observations. The degree of crystallinity was analyzed by differential scanning calorimetry (DSC). Wide-angle X-ray scattering diffraction (WAXS) analysis was used to partially characterize the PA6 structure after the HE process. The contents of various forms of the crystalline phase in PA6 samples before and after the HE process were analyzed in fragments of spectroscopy in infrared (FTIR). The favorable properties of PA6 after the HE process were obtained after deformation under conditions generating an adiabatic temperature higher than the glass transition temperature and lower than the temperature of the onset of melting of the crystalline phase. Thermal analysis using DSC allowed us to conclude that in the PA6 after the HE process generating deformations in the range of 0.68–1.56, the proportion of the crystalline phase α increases in PA6. As the deformation increases in the HE process, the crystalline phase proportion increases by 12% compared to the initial material (before HE). The glass transition temperature of PA6 is ca. 50.6 °C, reduced for the sample after the HE process at a small deformation of 0.68 (PA6_0.68) to ca. 44.2 °C. For other samples, T<sub>g</sub> is ca. 53.2–53.5 °C. As a result of the analysis of WAXS diffractograms of PA6 samples after various deformations in the HE process, the presence of typical peaks of phases α<sub>1</sub> and α<sub>2</sub> and γ was observed. The results of the FTIR spectroscopic analysis confirm these observations that as the deformation increases, the proportion of the crystalline phase α increases. |
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| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-11T04:14:17Z |
| publishDate | 2023-04-01 |
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| record_format | Article |
| series | Materials |
| spelling | doaj.art-864e13507ff04805a53efeb5d2c368fa2023-11-17T23:16:03ZengMDPI AGMaterials1996-19442023-04-01169343510.3390/ma16093435Structural Hierarchy of PA6 Macromolecules after Hydrostatic ExtrusionMonika Skorupska0Mariusz Kulczyk1Piotr Denis2Dominik Grzęda3Anna Czajka4Joanna Ryszkowska5Institute of High Pressure Physics, Polish Academy of Sciences (Unipress), Sokołowska 29, 01-142 Warsaw, PolandInstitute of High Pressure Physics, Polish Academy of Sciences (Unipress), Sokołowska 29, 01-142 Warsaw, PolandInstitute of Fundamental Technological Research, Polish Academy of Sciences, Pawinskiego 5B, 02-106 Warsaw, PolandFaculty of Materials Science and Engineering, Warsaw University of Technology, Ul. Wołoska 141, 02-507 Warsaw, PolandFaculty of Materials Science and Engineering, Warsaw University of Technology, Ul. Wołoska 141, 02-507 Warsaw, PolandFaculty of Materials Science and Engineering, Warsaw University of Technology, Ul. Wołoska 141, 02-507 Warsaw, PolandThis article presents the influence of severe plastic deformation by hydrostatic extrusion (HE) on the thermal and structural properties of polyamide 6 (PA6). During the hydrostatic extrusion process, a fibrous structure oriented along the extrusion direction is formed, which was visualized during microscopic observations. The degree of crystallinity was analyzed by differential scanning calorimetry (DSC). Wide-angle X-ray scattering diffraction (WAXS) analysis was used to partially characterize the PA6 structure after the HE process. The contents of various forms of the crystalline phase in PA6 samples before and after the HE process were analyzed in fragments of spectroscopy in infrared (FTIR). The favorable properties of PA6 after the HE process were obtained after deformation under conditions generating an adiabatic temperature higher than the glass transition temperature and lower than the temperature of the onset of melting of the crystalline phase. Thermal analysis using DSC allowed us to conclude that in the PA6 after the HE process generating deformations in the range of 0.68–1.56, the proportion of the crystalline phase α increases in PA6. As the deformation increases in the HE process, the crystalline phase proportion increases by 12% compared to the initial material (before HE). The glass transition temperature of PA6 is ca. 50.6 °C, reduced for the sample after the HE process at a small deformation of 0.68 (PA6_0.68) to ca. 44.2 °C. For other samples, T<sub>g</sub> is ca. 53.2–53.5 °C. As a result of the analysis of WAXS diffractograms of PA6 samples after various deformations in the HE process, the presence of typical peaks of phases α<sub>1</sub> and α<sub>2</sub> and γ was observed. The results of the FTIR spectroscopic analysis confirm these observations that as the deformation increases, the proportion of the crystalline phase α increases.https://www.mdpi.com/1996-1944/16/9/3435hydrostatic extrusionpolyamide 6structurethermal properties |
| spellingShingle | Monika Skorupska Mariusz Kulczyk Piotr Denis Dominik Grzęda Anna Czajka Joanna Ryszkowska Structural Hierarchy of PA6 Macromolecules after Hydrostatic Extrusion Materials hydrostatic extrusion polyamide 6 structure thermal properties |
| title | Structural Hierarchy of PA6 Macromolecules after Hydrostatic Extrusion |
| title_full | Structural Hierarchy of PA6 Macromolecules after Hydrostatic Extrusion |
| title_fullStr | Structural Hierarchy of PA6 Macromolecules after Hydrostatic Extrusion |
| title_full_unstemmed | Structural Hierarchy of PA6 Macromolecules after Hydrostatic Extrusion |
| title_short | Structural Hierarchy of PA6 Macromolecules after Hydrostatic Extrusion |
| title_sort | structural hierarchy of pa6 macromolecules after hydrostatic extrusion |
| topic | hydrostatic extrusion polyamide 6 structure thermal properties |
| url | https://www.mdpi.com/1996-1944/16/9/3435 |
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