Coarse-Grained Simulations on Polyethylene Crystal Network Formation and Microstructure Analysis
Understanding and characterizing semi-crystalline models with crystalline and amorphous segments is crucial for industrial applications. A coarse-grained molecular dynamics (CGMD) simulations study probed the crystal network formation in high-density polyethylene (HDPE) from melt, and shed light on...
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MDPI AG
2024-04-01
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| Series: | Polymers |
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| Online Access: | https://www.mdpi.com/2073-4360/16/7/1007 |
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| author | Mohammed Althaf Hussain Takashi Yamamoto Syed Farooq Adil Shigeru Yao |
| author_facet | Mohammed Althaf Hussain Takashi Yamamoto Syed Farooq Adil Shigeru Yao |
| author_sort | Mohammed Althaf Hussain |
| collection | DOAJ |
| description | Understanding and characterizing semi-crystalline models with crystalline and amorphous segments is crucial for industrial applications. A coarse-grained molecular dynamics (CGMD) simulations study probed the crystal network formation in high-density polyethylene (HDPE) from melt, and shed light on tensile properties for microstructure analysis. Modified Paul–Yoon–Smith (PYS/R) forcefield parameters are used to compute the interatomic forces among the PE chains. The isothermal crystallization at 300 K and 1 atm predicts the multi-nucleus crystal growth; moreover, the lamellar crystal stems and amorphous region are alternatively oriented. A one-dimensional density distribution along the alternative lamellar stems further confirms the ordering of the lamellar-stack orientation. Using this plastic model preparation approach, the semi-crystalline model density (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi>ρ</mi></mrow><mrow><mi>c</mi><mi>r</mi></mrow></msub></mrow></semantics></math></inline-formula>) of ca. 0.913 g·cm<sup>−3</sup> and amorphous model density (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi>ρ</mi></mrow><mrow><mi>a</mi><mi>m</mi></mrow></msub></mrow></semantics></math></inline-formula>) of ca. 0.856 g·cm<sup>−3</sup> are obtained. Furthermore, the ratio of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mrow><mrow><msub><mrow><mi>ρ</mi></mrow><mrow><mi>c</mi><mi>r</mi></mrow></msub></mrow><mo>/</mo><mrow><msub><mrow><mi>ρ</mi></mrow><mrow><mi>a</mi><mi>m</mi></mrow></msub></mrow></mrow></mrow></semantics></math></inline-formula> ≈ 1.06 is in good agreement with computational (≈1.096) and experimental (≈1.14) data, ensuring the reliability of the simulations. The degree of crystallinity (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi>χ</mi></mrow><mrow><mi>c</mi></mrow></msub></mrow></semantics></math></inline-formula>) of the model is ca. 52% at 300 K. Nevertheless, there is a gradual increase in crystallinity over the specified time, indicating the alignment of the lamellar stems during crystallization. The characteristic stress–strain curve mimicking tensile tests along the z-axis orientation exhibits a reversible sharp elastic regime, tensile strength at yield ca. 100 MPa, and a non-reversible tensile strength at break of 350%. The cavitation mechanism embraces the alignment of lamellar stems along the deformation axis. The study highlights an explanatory model of crystal network formation for the PE model using a PYS/R forcefield, and it produces a microstructure with ordered lamellar and amorphous segments with robust mechanical properties, which aids in predicting the microstructure–mechanical property relationships in plastics under applied forces. |
| first_indexed | 2024-04-24T10:35:50Z |
| format | Article |
| id | doaj.art-a5b7c774512b41d9a37af4144b2b7e56 |
| institution | Directory Open Access Journal |
| issn | 2073-4360 |
| language | English |
| last_indexed | 2024-04-24T10:35:50Z |
| publishDate | 2024-04-01 |
| publisher | MDPI AG |
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| series | Polymers |
| spelling | doaj.art-a5b7c774512b41d9a37af4144b2b7e562024-04-12T13:25:19ZengMDPI AGPolymers2073-43602024-04-01167100710.3390/polym16071007Coarse-Grained Simulations on Polyethylene Crystal Network Formation and Microstructure AnalysisMohammed Althaf Hussain0Takashi Yamamoto1Syed Farooq Adil2Shigeru Yao3Central Research Institute, Fukuoka University, Fukuoka 814-0180, JapanGraduate School of Science and Engineering, Yamaguchi University, Yamaguchi 753-8512, JapanDepartment of Chemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi ArabiaCentral Research Institute, Fukuoka University, Fukuoka 814-0180, JapanUnderstanding and characterizing semi-crystalline models with crystalline and amorphous segments is crucial for industrial applications. A coarse-grained molecular dynamics (CGMD) simulations study probed the crystal network formation in high-density polyethylene (HDPE) from melt, and shed light on tensile properties for microstructure analysis. Modified Paul–Yoon–Smith (PYS/R) forcefield parameters are used to compute the interatomic forces among the PE chains. The isothermal crystallization at 300 K and 1 atm predicts the multi-nucleus crystal growth; moreover, the lamellar crystal stems and amorphous region are alternatively oriented. A one-dimensional density distribution along the alternative lamellar stems further confirms the ordering of the lamellar-stack orientation. Using this plastic model preparation approach, the semi-crystalline model density (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi>ρ</mi></mrow><mrow><mi>c</mi><mi>r</mi></mrow></msub></mrow></semantics></math></inline-formula>) of ca. 0.913 g·cm<sup>−3</sup> and amorphous model density (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi>ρ</mi></mrow><mrow><mi>a</mi><mi>m</mi></mrow></msub></mrow></semantics></math></inline-formula>) of ca. 0.856 g·cm<sup>−3</sup> are obtained. Furthermore, the ratio of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mrow><mrow><msub><mrow><mi>ρ</mi></mrow><mrow><mi>c</mi><mi>r</mi></mrow></msub></mrow><mo>/</mo><mrow><msub><mrow><mi>ρ</mi></mrow><mrow><mi>a</mi><mi>m</mi></mrow></msub></mrow></mrow></mrow></semantics></math></inline-formula> ≈ 1.06 is in good agreement with computational (≈1.096) and experimental (≈1.14) data, ensuring the reliability of the simulations. The degree of crystallinity (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi>χ</mi></mrow><mrow><mi>c</mi></mrow></msub></mrow></semantics></math></inline-formula>) of the model is ca. 52% at 300 K. Nevertheless, there is a gradual increase in crystallinity over the specified time, indicating the alignment of the lamellar stems during crystallization. The characteristic stress–strain curve mimicking tensile tests along the z-axis orientation exhibits a reversible sharp elastic regime, tensile strength at yield ca. 100 MPa, and a non-reversible tensile strength at break of 350%. The cavitation mechanism embraces the alignment of lamellar stems along the deformation axis. The study highlights an explanatory model of crystal network formation for the PE model using a PYS/R forcefield, and it produces a microstructure with ordered lamellar and amorphous segments with robust mechanical properties, which aids in predicting the microstructure–mechanical property relationships in plastics under applied forces.https://www.mdpi.com/2073-4360/16/7/1007MD simulationssemi-crystalline structurepolymer physicspolymer networkcrystallizationrelaxation |
| spellingShingle | Mohammed Althaf Hussain Takashi Yamamoto Syed Farooq Adil Shigeru Yao Coarse-Grained Simulations on Polyethylene Crystal Network Formation and Microstructure Analysis Polymers MD simulations semi-crystalline structure polymer physics polymer network crystallization relaxation |
| title | Coarse-Grained Simulations on Polyethylene Crystal Network Formation and Microstructure Analysis |
| title_full | Coarse-Grained Simulations on Polyethylene Crystal Network Formation and Microstructure Analysis |
| title_fullStr | Coarse-Grained Simulations on Polyethylene Crystal Network Formation and Microstructure Analysis |
| title_full_unstemmed | Coarse-Grained Simulations on Polyethylene Crystal Network Formation and Microstructure Analysis |
| title_short | Coarse-Grained Simulations on Polyethylene Crystal Network Formation and Microstructure Analysis |
| title_sort | coarse grained simulations on polyethylene crystal network formation and microstructure analysis |
| topic | MD simulations semi-crystalline structure polymer physics polymer network crystallization relaxation |
| url | https://www.mdpi.com/2073-4360/16/7/1007 |
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