Qiu L, Ouyang Y, Feng Y, Zhang X
School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China.
Rev Sci Instrum. 2018 Sep;89(9):096112. doi: 10.1063/1.5052692.
Porous polyimide fiber enjoys a good reputation as a high temperature resistant thermal insulation material in an aircraft-carrier, a spacecraft, and other military sophisticated products. Understanding its thermal conductivity is especially important for the design optimization and thermal management in these applications. In this study, a modified wire-shape 3 method is developed to measure the thermal conductivity of individual porous polyimide fibers, utilizing a platinum layer heater/thermometer deposited along the circumferential direction of the fiber. The new method is first validated using a platinum wire with known thermophysical properties such as thermal conductivity at room temperature and then applied to porous polyimide fibers with diverse porosities. The thermal conductivity of porous polyimide fibers at room temperature is 0.06-0.15 W m K, which reflects a good thermal insulation performance.
多孔聚酰亚胺纤维作为一种耐高温隔热材料，在航空母舰、航天器及其他军事尖端产品中享有良好声誉。了解其热导率对于这些应用中的设计优化和热管理尤为重要。在本研究中，开发了一种改进的丝状3方法来测量单个多孔聚酰亚胺纤维的热导率，该方法利用沿纤维圆周方向沉积的铂层加热器/温度计。首先使用具有已知热物理性质（如室温下的热导率）的铂丝对新方法进行验证，然后将其应用于具有不同孔隙率的多孔聚酰亚胺纤维。多孔聚酰亚胺纤维在室温下的热导率为0.06 - 0.15 W m K，这反映了其良好的隔热性能。
