Synthesis of Biobased Polyamide PA5T and Its Furan Copolymer and Study on Non‑isothermal Crystallization Kinetics

The biobased monomers have been widely used to address climate change and biodiversity loss. In this study, the high heat-resistant poly(pentamethylene terephthalamide) (PA5T) and furan copolymer poly(pentamethylene terephthalamide/pentamethylene furanamide) (PA5T/5F) were synthesized successfully. Importantly, the 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD)-catalyzed bulk polymerization combining the solid state polycondensation (SSP) as a facile, green and robust route was chosen. The PA5T and PA5T/5F had high melting temperatures at 350.8 and 309.8 °C, respectively. Besides, their initial decomposition temperatures, evaluated as the temperature at 5% mass loss ( T 5% ) were at 420.0 and 413.2 °C, respectively, higher than melting temperatures, which demonstrated that furan unit had considerable thermal stability with benzene ring and they had great melt processing without thermal decomposition. It was first found that end amino groups after side reaction of N-methylation still could react with esters to form amides in solid state polycondensation. Additionally, the non-isothermal crystallization kinetics of PA5T and PA5T/5F were systematically studied by Jeziorny method and Mo method. It is found that crystallization rate of PA5T was greater, and the crystallization activation energy of PA5T/5F determined by the differential isoconversional method of Friedman was larger at the same relative crystallinities.