Crystallization and Melting Behavior of Trogamid

摘要

Non-isothermal and isothermal crystallization and subsequent melting behavior have been studied for Trogamid CX7323, a chemical relative of nylon 6. Using temperature modulated differential scanning calorimetry, we monitored the melt crystallization process for various cooling rates, and isothermally for different degrees of undercooling. Crystallization rate strongly depends on the isothermal crystallization temperature, T_c. As is typical, crystals nucleate and grow much faster at higher undercooling (lower value of T_c). The crystallization kinetics, as indicated by time development of relative crystallinity, follows an Avrami equation, giving an Avrami exponent n≈2 for the primary process of crystallization. Significant differences between crystals formed at high and low temperatures are observed by heating samples at 5 °C/min immediately after isothermal crystallization without cooling. Crystals formed at lower temperatures (160 °C and 180 °C) give rise to two endothermic peaks, at 250 °C and 262 °C, while crystals formed at higher temperature (220 °C to 230°C) show only one endothermic peak at 255 °C.