聚氨酯泡沫低温下平均线膨胀系数的测定

使用相对比较法对聚氨酯泡沫从液氮温度到室温的平均线膨胀系数进行了测试。采用的试验装置具有微机自动测温系统、抽真空系统以及电加热系统 ,保证了测试的准确性。结果表明 :聚氨酯泡沫具有非常低的平均线膨胀系数 ,在平行与垂直发泡方向的膨胀性能差异不大。最后对试验进行了误差分析 ,得到最大相对误差为 8%。

Measurement of Mean Linear Thermal Expansion Coefficient of Polyurethane Foam in the Temperature Range from Liquid Nitrogen to Room Temperature by Means of Relative Comparison Method

The mean linear thermal expansion coefficient of polyurethane foam was measured from liquid temperature to room temperature by means of relative comparison method in this paper. The result was accurate because such properties as automatic temperature measuring system? pumped vacuum system and electrical heating system were adopted in the measuring equipment. A very low mean linear thermal expansion coefficient and little discrepancy between rising direction of the foam and direction perpendicular to bubble blowing were showed by the measuring result. At last, the maximum relative error about the experiment was got, which is 8%.