尼龙66的多重熔融行为

摘要

Either of the two endothermic melting peaks of nylon 66 found by differential thermal analysis can be convert-ed to the other by appropriate choice of annealing conditions. The two peaks are considered due to the melting of two mor-phological species, forms 1 and forms 2. Form 1 is relatively fixed in melting temperature, while the melting temperatureof form 2 varies with annealing conditions. It has been shown that form 1 results from rapid cooling from the melt, andform 2 results from slow cooling. Form 1 appears to be kinetically favored, while form 2 is thermodynamically preferred.The variability in the form 2 melting point is attributed to variable crystal size and/or perfection.%研究了尼龙66的双重熔融峰的转变行为。高温峰(峰1)的熔融温度几乎不变，低温峰(峰2)的熔融温度随着退火时间的延长逐渐升高。全部退火时间内双峰的总面积保持不变，而高温峰、低温峰的相对面积比变小。高温峰被认为来自于熔体的快速冷却(动力学优先)，低温峰则来自于缓慢冷却(热力学优先)。低温峰向高温峰的转变是由于不同的结晶尺寸和/或完善程度引起。