Crystallization Regimes and Spherulitic Morphology of Poly(trimethylene terephthalate/isophthalate) Random Copolyesters

摘要

The crystallization regimes and spherulitic morphology of poly(trimethylene terephthalate/isophthalate) (TI) random copolyesters were studied in this work. A hot stage polarizing microscope was used to observe morphology and measure growth rate of the spherulite of TI copolyesters. Lauritzen-Hoffman secondary nucleation theory was applied to investigate crystallization kinetics and regimes of TI copolyesters. Results show that the spherulitic growth rate decreased with an increase in isophthalic acid content of the copolyesters. The analysis of Lauritzen-Hoffman secondary nucleation theory shows that regime I, II, and III were observed in TI11 and TI21. Regime I→II was observed in TI29. The spherulitic morphology of TI11, TI21, and TI29 changed from elliptical-shaped spherulite to irregular spherulite and then to normal spherulite at the regime transitions.