DSC测试中样品内部的温度分布及其对比热测试的影响  

TEMPERATURE DISTRIBUTION IN THE SAMPLE AND ITS EFFECT ON THE DETERMINATION OF HEAT CAPACITY IN DSC MEASUREMENTS

作　　者：赵冬梅[1] 李丽霞[1] 郑扬[1] 左阳[1] 刘国栋[1] 

机构地区：[1]河北工业大学化工学院,天津300130

出　　处：《高分子学报》2012年第7期754-758,共5页Acta Polymerica Sinica

基　　金：国家自然科学青年基金(基金号20804013);河北省自然科学基金(基金号B2012202148);教育部功能高分子材料重点实验室开放基金资助

摘　　要：由傅里叶导热定律结合Tools-Narayanaswamy-Moynihan(TNM)松弛模型提出了一种计算聚合物样品内温度分布的方法.对PS的计算结果表明温度梯度随样品厚度、升温速率增大而增大,对于1.0 mm的PS以1 K/min降温后再以10 K/min升温时样品内部最大温差为0.882 K.在此基础上提出了不同样品厚度、不同热处理条件下聚合物测定比热的计算方法,结果表明计算结果与实测数据基本一致.A method for calculating the temperature distribution in the polymer sample during DSC measurements was proposed in this paper based on the one-dimensional heat conduction equation and Tools- Narayanaswamy-Moynihan （TNM） model. It was found that the temperature lag increased remarkably with increasing sample thickness and heating rate. A maximum temperature difference between the center and the surface of a PS sample with 1.0 mm thickness was calculated to be 0. 882 K when it was heated at a rate of 10 K/min after cooling at 1 K/min. Meanwhile, a method for calculating the sensible heat capacity of the polymer with different thicknesses after different thermal treatments was proposed. The theoretical results were consistent with the experimental data.

关 键 词：DSC 比热 玻璃化转变 焓松弛 聚苯乙烯 温度梯度 

分 类 号：TB302[一般工业技术—材料科学与工程]