Abstract
Nylon 5I is one of the new bio-based nylon materials. Its raw material 1,5-pentanediamine (PDA) is prepared by biological methods using biomass as the raw material. The high-performance polymer materials require the original high-quality monomers. 1,5-Pentanediamine–isophthalate (PDA–IPA) was taken as the direct monomer for the preparation of nylon 5I, and the crystallization was a valuable and essential approach to preparing the good-performance monomer salt. In this report, we found and obtained two crystal forms of PDA–IPA, monohydrate and an anhydrous form. Their crystal structures were determined and analyzed by single crystal X-ray diffraction (SCXRD), powder X-ray diffraction (PXRD), and Fourier transform infrared spectroscopy (FTIR). Hirshfeld surface maps were employed to capture the differences in the interactions present in the two forms. The thermal behaviors were characterized by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Moreover, the monohydrate and anhydrous phase can transform to each other through solid–solid transformation or solution-mediated phase transformation, and the critical values of the phase transformation were determined. Finally, the relative stability of the two forms under different thermodynamic conditions was discussed, especially the influence of temperature and water activity on the stability.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.