【摘要】 应用自行研制的亚微米/微米薄膜材料热物理性质多功能测试仪和差示扫描量热仪(DSC)对聚酰亚胺PI及其渗碳改性复合薄膜PI/C的热膨胀系数、热扩散系数和比热进行了实验研究和理论分析,揭示了在20℃至150℃温区内温度对渗碳量30wt%的PI/C复合薄膜的热物性的影响规律和机制。结果显示渗碳量30wt%的复合薄膜比纯PI热膨胀系数减小,导热性能明显提高,且没有改变性能对温度的依赖关系。对PI/C(30wt%)应用加和原理计算的比热值与实测值相吻合,应用Nielson模型和Cheng-Vachon模型的预测值与导热系数实测值基本吻合。更多还原

【Abstract】 CCD imaging technique,laser flash method and differential scanning calorimeter were utilized to measure the thermal expansion,thermal diffusivity and specific heat of polyimide(PI) films and carbon modified PI composite films(PI/C) at different temperatures.Influences of carbon and temperature on the thermophysical properties of PI/C(30wt%) were analyzed.Results show that the addition of carbon increases the thermal conductivity apparently and decreases thermal expansion between 20℃ and 150℃.The temperature dependences of thermal expansion and thermal conductivity were not changed.The specific heat of PI/C(30wt%) calculated by the addition principle and thermal conductivity of PI/C(30wt%) calculated by the Nielson model and Cheng-Vachon model agree with the measured values.更多还原