Lamellar crystallization of poly(trimethylene terephthalate)

• Published in: Polymer journal Vol. 55; no. 7; pp. 775 - 783
• Main Authors: Tadokoro, Daisuke, Konishi, Takashi, Fukao, Koji, Miyamoto, Yoshihisa
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.07.2023; Nature Publishing Group
• Subjects: 639/301/923/1028; 639/766; Biomaterials; Bioorganic Chemistry; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Crystallization; Lamellar structure; Melt temperature; Melting; Mesophase; Nucleation; Optical microscopy; Original Article; Polymer Sciences; Supercooling; Surfaces and Interfaces; Temperature dependence; Terephthalate; Thickness; Thin Films; X-ray scattering
• ISSN: 0032-3896; 1349-0540
• DOI: 10.1038/s41428-023-00777-6

The dependence of lamellar thickness on the melting temperature and crystallization temperature and the crystallization temperature dependence of the growth rate for poly(trimethylene terephthalate) (PTT) were examined with small-angle X-ray scattering (SAXS), wide angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC) and optical microscopy. The melting temperature of the isothermally crystallized PTT lamellar stack structure was determined by X-ray measurements. The equilibrium melting temperature of PTT was determined to be 290.5 °C from the relationship between the melting temperature and the lamellar thickness. The relationships of supercooling to the lamellar thickness and the growth rate were analyzed. The excess thickness δl  = 7.1 Å was obtained from the data provided above for the crystallization temperature, T c  = 173.7 °C. The temperature dependence of the lamellar thickness below T c  = 173.7 °C suggested crystallization through a mesophase. The temperature dependence of the growth rate was explained by secondary nucleation theory over a wide crystallization temperature range. The melting temperature of the isothermally crystallized poly(trimethylene terephthalate) (PTT) lamellar stack structure was determined by X-ray measurements. The equilibrium melting temperature of PTT was determined to be 290.5 °C from the relationship between the melting temperature and the lamellar thickness. The temperature dependence of the lamellar thickness below T c  = 173.7 °C suggested crystallization through a mesophase. The temperature dependence of the growth rate was explained by secondary nucleation theory over a wide crystallization temperature range.