Consequences of Radiothermal Ageing on the Crystalline Morphology of Additive-Free Silane-Crosslinked Polyethylene
The radiothermal ageing of silane-crosslinked low-density PE (Si-XLPE) films was studied in the air under three different <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="sans-serif">γ&...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2022-07-01
|
| Series: | Polymers |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2073-4360/14/14/2912 |
| _version_ | 1797433119371952128 |
|---|---|
| author | Sarah Hettal Sébastien Roland Xavier Colin |
| author_facet | Sarah Hettal Sébastien Roland Xavier Colin |
| author_sort | Sarah Hettal |
| collection | DOAJ |
| description | The radiothermal ageing of silane-crosslinked low-density PE (Si-XLPE) films was studied in the air under three different <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="sans-serif">γ</mi></semantics></math></inline-formula> dose rates (8.5, 77.8, and 400 Gy·h<sup>−1</sup>) at a low temperature close to ambient (47, 47, and 21 °C, respectively). Changes in crystalline morphology were investigated using a multi-technique approach based on differential scanning calorimetry (DSC), wide- (WAXS) and small-angle X-ray scattering (SAXS), and density measurements. In particular, the changes in four structural variables were accurately monitored during radiothermal ageing: crystallinity ratio (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi mathvariant="normal">X</mi><mi mathvariant="normal">C</mi></msub></mrow></semantics></math></inline-formula>), crystalline lamellae thickness (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi mathvariant="normal">L</mi><mi mathvariant="normal">C</mi></msub></mrow></semantics></math></inline-formula>), long period (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi mathvariant="normal">L</mi><mi mathvariant="normal">p</mi></msub></mrow></semantics></math></inline-formula>), and interlamellar spacing (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi mathvariant="normal">L</mi><mi mathvariant="normal">a</mi></msub></mrow></semantics></math></inline-formula>). Concerning the changes in <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi mathvariant="normal">X</mi><mi mathvariant="normal">C</mi></msub></mrow></semantics></math></inline-formula>, a perfect agreement was found between DSC and WAXS experiments. Successive sequences of self-nucleation and annealing (SSA) were also performed on aged Si-XLPE samples in the DSC chamber in order to assess the thickness distribution of crystalline lamellae. This method allowed the thermally splitting of the melting domain of Si-XLPE into a series of elementary melting peaks, with each one characterised by a distinct thickness of crystalline lamellae. DSC (used with the SSA method) showed a slight increase in <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi mathvariant="normal">L</mi><mi mathvariant="normal">C</mi></msub></mrow></semantics></math></inline-formula> during the oxidation of Si-XLPE, while SAXS confirmed a catastrophic decrease in <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi mathvariant="normal">L</mi><mi mathvariant="normal">a</mi></msub></mrow></semantics></math></inline-formula>. The critical value of the interlamellar spacing characterising the ductile/brittle transition of Si-XLPE was found to be of the same order of magnitude as that for linear polyethylene (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi mathvariant="normal">L</mi><mrow><mi>aF</mi></mrow></msub><mo>≈</mo><mn>6</mn></mrow></semantics></math></inline-formula> nm). This structural end-of-life criterion can now be used for predicting the lifetime of Si-XLPE in a nuclear environment. |
| first_indexed | 2024-03-09T10:12:35Z |
| format | Article |
| id | doaj.art-7e638dda6ebc488bb52c4989a9d5d76b |
| institution | Directory Open Access Journal |
| issn | 2073-4360 |
| language | English |
| last_indexed | 2024-03-09T10:12:35Z |
| publishDate | 2022-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Polymers |
| spelling | doaj.art-7e638dda6ebc488bb52c4989a9d5d76b2023-12-01T22:36:54ZengMDPI AGPolymers2073-43602022-07-011414291210.3390/polym14142912Consequences of Radiothermal Ageing on the Crystalline Morphology of Additive-Free Silane-Crosslinked PolyethyleneSarah Hettal0Sébastien Roland1Xavier Colin2Laboratoire Procédés et Ingénierie en Mécanique et Matériaux, Arts et Métiers Institute of Technology, CNRS, CNAM, HESAM University, 151 Boulevard de l’Hôpital, 75013 Paris, FranceLaboratoire Procédés et Ingénierie en Mécanique et Matériaux, Arts et Métiers Institute of Technology, CNRS, CNAM, HESAM University, 151 Boulevard de l’Hôpital, 75013 Paris, FranceLaboratoire Procédés et Ingénierie en Mécanique et Matériaux, Arts et Métiers Institute of Technology, CNRS, CNAM, HESAM University, 151 Boulevard de l’Hôpital, 75013 Paris, FranceThe radiothermal ageing of silane-crosslinked low-density PE (Si-XLPE) films was studied in the air under three different <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="sans-serif">γ</mi></semantics></math></inline-formula> dose rates (8.5, 77.8, and 400 Gy·h<sup>−1</sup>) at a low temperature close to ambient (47, 47, and 21 °C, respectively). Changes in crystalline morphology were investigated using a multi-technique approach based on differential scanning calorimetry (DSC), wide- (WAXS) and small-angle X-ray scattering (SAXS), and density measurements. In particular, the changes in four structural variables were accurately monitored during radiothermal ageing: crystallinity ratio (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi mathvariant="normal">X</mi><mi mathvariant="normal">C</mi></msub></mrow></semantics></math></inline-formula>), crystalline lamellae thickness (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi mathvariant="normal">L</mi><mi mathvariant="normal">C</mi></msub></mrow></semantics></math></inline-formula>), long period (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi mathvariant="normal">L</mi><mi mathvariant="normal">p</mi></msub></mrow></semantics></math></inline-formula>), and interlamellar spacing (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi mathvariant="normal">L</mi><mi mathvariant="normal">a</mi></msub></mrow></semantics></math></inline-formula>). Concerning the changes in <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi mathvariant="normal">X</mi><mi mathvariant="normal">C</mi></msub></mrow></semantics></math></inline-formula>, a perfect agreement was found between DSC and WAXS experiments. Successive sequences of self-nucleation and annealing (SSA) were also performed on aged Si-XLPE samples in the DSC chamber in order to assess the thickness distribution of crystalline lamellae. This method allowed the thermally splitting of the melting domain of Si-XLPE into a series of elementary melting peaks, with each one characterised by a distinct thickness of crystalline lamellae. DSC (used with the SSA method) showed a slight increase in <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi mathvariant="normal">L</mi><mi mathvariant="normal">C</mi></msub></mrow></semantics></math></inline-formula> during the oxidation of Si-XLPE, while SAXS confirmed a catastrophic decrease in <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi mathvariant="normal">L</mi><mi mathvariant="normal">a</mi></msub></mrow></semantics></math></inline-formula>. The critical value of the interlamellar spacing characterising the ductile/brittle transition of Si-XLPE was found to be of the same order of magnitude as that for linear polyethylene (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi mathvariant="normal">L</mi><mrow><mi>aF</mi></mrow></msub><mo>≈</mo><mn>6</mn></mrow></semantics></math></inline-formula> nm). This structural end-of-life criterion can now be used for predicting the lifetime of Si-XLPE in a nuclear environment.https://www.mdpi.com/2073-4360/14/14/2912silane-crosslinked polyethyleneradiothermal oxidationchain scissionschemicrystallisationlamellar thickeningembrittlement |
| spellingShingle | Sarah Hettal Sébastien Roland Xavier Colin Consequences of Radiothermal Ageing on the Crystalline Morphology of Additive-Free Silane-Crosslinked Polyethylene Polymers silane-crosslinked polyethylene radiothermal oxidation chain scissions chemicrystallisation lamellar thickening embrittlement |
| title | Consequences of Radiothermal Ageing on the Crystalline Morphology of Additive-Free Silane-Crosslinked Polyethylene |
| title_full | Consequences of Radiothermal Ageing on the Crystalline Morphology of Additive-Free Silane-Crosslinked Polyethylene |
| title_fullStr | Consequences of Radiothermal Ageing on the Crystalline Morphology of Additive-Free Silane-Crosslinked Polyethylene |
| title_full_unstemmed | Consequences of Radiothermal Ageing on the Crystalline Morphology of Additive-Free Silane-Crosslinked Polyethylene |
| title_short | Consequences of Radiothermal Ageing on the Crystalline Morphology of Additive-Free Silane-Crosslinked Polyethylene |
| title_sort | consequences of radiothermal ageing on the crystalline morphology of additive free silane crosslinked polyethylene |
| topic | silane-crosslinked polyethylene radiothermal oxidation chain scissions chemicrystallisation lamellar thickening embrittlement |
| url | https://www.mdpi.com/2073-4360/14/14/2912 |
| work_keys_str_mv | AT sarahhettal consequencesofradiothermalageingonthecrystallinemorphologyofadditivefreesilanecrosslinkedpolyethylene AT sebastienroland consequencesofradiothermalageingonthecrystallinemorphologyofadditivefreesilanecrosslinkedpolyethylene AT xaviercolin consequencesofradiothermalageingonthecrystallinemorphologyofadditivefreesilanecrosslinkedpolyethylene |