DSC法测定联苯的热力学性质与纯度

摘要

The melting point,melting enthalpy and enthalpy of crystallization were determined with DSC(Differential Scanning Calorimeter). The research showed that heating/cooling rate had a great influence on the melting point of biphenyl,but little effect on the melting enthalpy or enthalpy of crystallization. Solid specific heat capacity at constant pres-sure(283.15~323.15,K)and liquid specific heat capacity at constant pressure(363.15~443.15,K)were measured. A model of the relationship between specific heat capacity at constant pressure and temperature was developed. Meanwhile,a method of determining biphenyl purity with DSC was introduced.%利用差示扫描量热仪(DSC)对联苯的熔点、熔融焓、结晶焓进行测定，实验结果显示在不同升温/降温速率下DSC 法对联苯的熔点的测定结果影响较大，而对熔融焓和结晶焓并无影响．测定联苯固体比定压热容(283.15～323.15,K)、液体比定压热容(363.15～443.15,K)，并将比定压热容与温度进行关联，导出计算比定压热容的方程．同时介绍利用DSC测得联苯纯度的方法．