Molecular Orientation and Mechanical Properties of Biomass-Derived Aliphatic Polyamide (PA11) by High-Pressure Compression Molding.
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| Title: | Molecular Orientation and Mechanical Properties of Biomass-Derived Aliphatic Polyamide (PA11) by High-Pressure Compression Molding. |
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| Authors: | Ura, Keisuke1,2 (AUTHOR) nishitsuji@yz.yamagata-u.ac.jp, Nishitsuji, Shotaro2 (AUTHOR), Kobayashi, Yutaka3 (AUTHOR), Ito, Hiroshi1,2,3 (AUTHOR) ihiroshi@yz.yamagata-u.ac.jp |
| Source: | Materials (1996-1944). Feb2026, Vol. 19 Issue 3, p513. 18p. |
| Subjects: | Compression molding, Molecular orientation, Plant polymers, Tensile strength, Polyamides, Phase transitions, Mechanical behavior of materials, Crystallization |
| Abstract: | Highlights: What are the main findings? This study demonstrated that high-pressure thermal compression molding significantly modifies the crystalline structure and mechanical properties of biomass-derived aliphatic polyamide PA11, specifically the grade Rilsan® BMN O TLD manufactured by Arkema—a fully bio-based resin derived from castor oil. The tensile fracture strength reached a maximum—approximately 2.4 times higher than that of the uncompressed sample—under experimental conditions of 140 °C and 1000 kN. This enhancement is proposed to be primarily attributable to the molecular orientation and crystallization of the δ', which remained stable without undergoing Brill transition even after cooling to room temperature, while its crystallinity increased, as supported by POM observations, WAXS analysis, and DSC analysis. In contrast, at 180 °C, although the degree of crystallinity increased, molecular orientation decreased, resulting in reduced tensile strength. These findings indicate that the mechanical properties of a fully biomass-derived aliphatic polyamide, PA11, which exhibits crystal polymorphism, are governed by a complex interplay among phase transitions, molecular orientation, and crystallization, all of which are strongly influenced by temperature and pressure conditions. What are the implications of the main findings? If the mechanical properties of the biomass-derived polyamide PA11 can be enhanced through high-pressure thermal compression molding, it could be utilized in a wider range of applications. This suggests the potential to shift from petroleum-derived polymers to renewable, biomass-derived polymers, thereby contributing to environmental sustainability. These results suggest that, even for polymers whose crystalline phases or structures typically change upon cooling to room temperature, the method has the potential to suppress such phase transformations. This capability may improve durability against strength degradation and dimensional changes under service conditions, and we therefore consider it a topic for future study. Expanding the application of this method to other biomass-derived polymers with various crystal polymorphs may allow temperature and pressure conditions to be combined to control phase transitions, molecular orientation, and crystallization. This approach has the potential to contribute not only to improved mechanical strength but also to enhancements in a range of other material properties. This study investigates the effects of high-pressure compression molding on the molecular orientation and mechanical properties of biomass-derived aliphatic polyamide (PA11). Tensile fracture strength exhibited a significant increase—up to 2.4 times that of untreated samples—under conditions of 1000 kN and 140 °C. Differential Scanning Calorimetry (DSC) and Wide-Angle X-ray Scattering (WAXS) analyses revealed a temperature- and pressure-dependent shift in crystalline phases, suggesting a transition from α' to phase. The δ' phase, formed by high-pressure compression molding, is retained even after cooling to room temperature (i.e., Brill transition was not observed). In addition, polarized optical microscopy (POM) observations further supported the presence of changes in molecular orientation. This enhancement (under conditions of 1000 kN and 140 °C) is primarily attributed to the molecular orientation. However, it is also noteworthy that the formation of the δ' phase is accompanied by an increase in the degree of crystallinity, and that this δ' phase is retained even after cooling to room temperature without undergoing a Brill transition. In contrast, at 180 °C, although the degree of crystallinity increased, molecular orientation decreased, resulting in reduced tensile strength. These findings indicate that the mechanical properties of PA11 are governed by a complex interplay among phase transitions, molecular orientation, and crystallization, all of which are strongly influenced by temperature and pressure conditions. These findings demonstrate that high-pressure compression molding is an effective method for enhancing the mechanical properties of PA11 through controlled phase transition and orientation [ABSTRACT FROM AUTHOR] |
| Copyright of Materials (1996-1944) is the property of MDPI and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
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| Items | – Name: Title Label: Title Group: Ti Data: Molecular Orientation and Mechanical Properties of Biomass-Derived Aliphatic Polyamide (PA11) by High-Pressure Compression Molding. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Ura%2C+Keisuke%22">Ura, Keisuke</searchLink><relatesTo>1,2</relatesTo> (AUTHOR)<i> nishitsuji@yz.yamagata-u.ac.jp</i><br /><searchLink fieldCode="AR" term="%22Nishitsuji%2C+Shotaro%22">Nishitsuji, Shotaro</searchLink><relatesTo>2</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Kobayashi%2C+Yutaka%22">Kobayashi, Yutaka</searchLink><relatesTo>3</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Ito%2C+Hiroshi%22">Ito, Hiroshi</searchLink><relatesTo>1,2,3</relatesTo> (AUTHOR)<i> ihiroshi@yz.yamagata-u.ac.jp</i> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Materials+%281996-1944%29%22">Materials (1996-1944)</searchLink>. Feb2026, Vol. 19 Issue 3, p513. 18p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Compression+molding%22">Compression molding</searchLink><br /><searchLink fieldCode="DE" term="%22Molecular+orientation%22">Molecular orientation</searchLink><br /><searchLink fieldCode="DE" term="%22Plant+polymers%22">Plant polymers</searchLink><br /><searchLink fieldCode="DE" term="%22Tensile+strength%22">Tensile strength</searchLink><br /><searchLink fieldCode="DE" term="%22Polyamides%22">Polyamides</searchLink><br /><searchLink fieldCode="DE" term="%22Phase+transitions%22">Phase transitions</searchLink><br /><searchLink fieldCode="DE" term="%22Mechanical+behavior+of+materials%22">Mechanical behavior of materials</searchLink><br /><searchLink fieldCode="DE" term="%22Crystallization%22">Crystallization</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: Highlights: What are the main findings? This study demonstrated that high-pressure thermal compression molding significantly modifies the crystalline structure and mechanical properties of biomass-derived aliphatic polyamide PA11, specifically the grade Rilsan® BMN O TLD manufactured by Arkema—a fully bio-based resin derived from castor oil. The tensile fracture strength reached a maximum—approximately 2.4 times higher than that of the uncompressed sample—under experimental conditions of 140 °C and 1000 kN. This enhancement is proposed to be primarily attributable to the molecular orientation and crystallization of the δ', which remained stable without undergoing Brill transition even after cooling to room temperature, while its crystallinity increased, as supported by POM observations, WAXS analysis, and DSC analysis. In contrast, at 180 °C, although the degree of crystallinity increased, molecular orientation decreased, resulting in reduced tensile strength. These findings indicate that the mechanical properties of a fully biomass-derived aliphatic polyamide, PA11, which exhibits crystal polymorphism, are governed by a complex interplay among phase transitions, molecular orientation, and crystallization, all of which are strongly influenced by temperature and pressure conditions. What are the implications of the main findings? If the mechanical properties of the biomass-derived polyamide PA11 can be enhanced through high-pressure thermal compression molding, it could be utilized in a wider range of applications. This suggests the potential to shift from petroleum-derived polymers to renewable, biomass-derived polymers, thereby contributing to environmental sustainability. These results suggest that, even for polymers whose crystalline phases or structures typically change upon cooling to room temperature, the method has the potential to suppress such phase transformations. This capability may improve durability against strength degradation and dimensional changes under service conditions, and we therefore consider it a topic for future study. Expanding the application of this method to other biomass-derived polymers with various crystal polymorphs may allow temperature and pressure conditions to be combined to control phase transitions, molecular orientation, and crystallization. This approach has the potential to contribute not only to improved mechanical strength but also to enhancements in a range of other material properties. This study investigates the effects of high-pressure compression molding on the molecular orientation and mechanical properties of biomass-derived aliphatic polyamide (PA11). Tensile fracture strength exhibited a significant increase—up to 2.4 times that of untreated samples—under conditions of 1000 kN and 140 °C. Differential Scanning Calorimetry (DSC) and Wide-Angle X-ray Scattering (WAXS) analyses revealed a temperature- and pressure-dependent shift in crystalline phases, suggesting a transition from α' to phase. The δ' phase, formed by high-pressure compression molding, is retained even after cooling to room temperature (i.e., Brill transition was not observed). In addition, polarized optical microscopy (POM) observations further supported the presence of changes in molecular orientation. This enhancement (under conditions of 1000 kN and 140 °C) is primarily attributed to the molecular orientation. However, it is also noteworthy that the formation of the δ' phase is accompanied by an increase in the degree of crystallinity, and that this δ' phase is retained even after cooling to room temperature without undergoing a Brill transition. In contrast, at 180 °C, although the degree of crystallinity increased, molecular orientation decreased, resulting in reduced tensile strength. These findings indicate that the mechanical properties of PA11 are governed by a complex interplay among phase transitions, molecular orientation, and crystallization, all of which are strongly influenced by temperature and pressure conditions. These findings demonstrate that high-pressure compression molding is an effective method for enhancing the mechanical properties of PA11 through controlled phase transition and orientation [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Materials (1996-1944) is the property of MDPI and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.3390/ma19030513 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 18 StartPage: 513 Subjects: – SubjectFull: Compression molding Type: general – SubjectFull: Molecular orientation Type: general – SubjectFull: Plant polymers Type: general – SubjectFull: Tensile strength Type: general – SubjectFull: Polyamides Type: general – SubjectFull: Phase transitions Type: general – SubjectFull: Mechanical behavior of materials Type: general – SubjectFull: Crystallization Type: general Titles: – TitleFull: Molecular Orientation and Mechanical Properties of Biomass-Derived Aliphatic Polyamide (PA11) by High-Pressure Compression Molding. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Ura, Keisuke – PersonEntity: Name: NameFull: Nishitsuji, Shotaro – PersonEntity: Name: NameFull: Kobayashi, Yutaka – PersonEntity: Name: NameFull: Ito, Hiroshi IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 02 Text: Feb2026 Type: published Y: 2026 Identifiers: – Type: issn-print Value: 19961944 Numbering: – Type: volume Value: 19 – Type: issue Value: 3 Titles: – TitleFull: Materials (1996-1944) Type: main |
| ResultId | 1 |
