10-290K环境下聚酰亚胺纤维导热性能研究.

Tn this experiment, the thermal conductivity of polyimide fibers at different temperatures is obtained by using transient electrothermal technology in order to explore the rule and cause of the variation of the thermal conductivity of polyimide fibers with temperature. The experimental results show that when the temperature is in the range of 1 0-290 K, with the decrease of temperature, the thermal diffusion coefficient of polyimide fiber increases gradually, and the thermal conductivity decreases gradually. Tn this paper, we start from the lattice vibration (phonon) thermal conductivity, and study the relationship between temperature and lattice vibration, phonon concentration, phonon mean free path and other experimental parameters. After excluding the influence of macroscopic defects such as pores, it is concluded that the crystallization rate is the main factor affecting the thermal conductivity of polyimide fibers near the glass transition temperature while the lattice vibration is the main factor affecting the thermal conductivity of polyimide fibers near the Debye temperature. Therefore, polyimide fibers can be prepared by changing the crystallization rate and improving process conditions to meet the needs of different life, production and scientific research. [ABSTRACT FROM AUTHOR]