采用差示扫描量热法测定蜡滴熔点

Determination of drop melting point of wax by differential scanning calorimetry

采用差示扫描量热(DSC)法测定蜡滴熔点,研究了升(降)温速率、升温次数对测试结果的影响,并在最优条件下考察了DSC法测蜡滴熔点的重复性、准确性和再现性。结果表明:确定熔融曲线终止边的拐点温度为DSC法的滴熔点;DSC法测蜡滴熔点的最优条件为:第1次升(降)温速率均为20℃/min,第2次升温速率为5℃/min;该方法的重复性在0~0.2℃,再现性在0~1.1℃,均满足GB/T 8026—2014的要求。

The drop melting point of wax was determined by using differential scanning calorimetry(DSC),and the effects of heating(cooling)rate and heating times on the test results were studied.The repeatability,accuracy and reproducibility of DSC method for measuring wax drop melting point were investigated under the optimal conditions.The results showed that the inflection point temperature at the end of the melting curve was determined to be the drop melting point of the DSC method.The optimal conditions for measuring the drop melting point of wax by DSC method were as follows:the first heating(cooling)rate was 20℃/min,the second heating rate was 5℃/min.The repeatability of the method was 0-0.2℃,and the reproducibility was 0-1.1℃,which both met the requirements of GB/T 8026—2014.