作者：Kunpeng Ruan, Yongqiang Guo and Junwei Gu*
关键字：Thermally conductive composites
论文来源：期刊
具体来源：Macromolecules
发表时间：2021年

Low intrinsic thermal conductivity coefficients (λ) of polyimide (PI) films limit their application in heat-prone flexible electronics. By optimizing liquid crystal range to fit curing temperature, a novel kind of intrinsically highly thermally conductive liquid crystalline PI (LC-PI) films are fabricated. When the molar ratio of 4, 4''-diaminodiphenyl ether (ODA) to 1, 4-bis(4-aminophenoxy)benzene (TPE-Q) is 1:3 (sample No. IV), liquid crystal range of preLC-PIIV films is 272~388^oC, including curing temperature of 350oC. The LC-PIIV films cured in liquid crystal range retain liquid crystal texture to room temperature, and the in-plane λ (λ∥) and through-plane λ (λ⊥) at room temperature reach 2.11 W/(m·K) and 0.32 W/(m·K), respectively, significantly higher than λ∥ (0.77 W/(m·K)) and λ⊥ (0.15 W/(m·K)) of LC-PII films which are cured out of liquid crystal range. Meanwhile, LC-PIIV films possess excellent mechanical and thermal properties, showing application prospects in high-heating flexible electronics.

聚酰亚胺（PI）膜较低的本征导热系数（λ）限制了其在易发热柔性电子器件的进一步应用。通过优化调控液晶区间与固化温度相匹配，制备出一种本征高导热液晶聚酰亚胺（LC-PI）膜。结果表明，当4, 4’-二氨基二苯醚（ODA）和1, 4-双（4-氨基苯氧基）苯（TPE-Q）的摩尔比为1：3时（IV号样品），preLC-PIIV膜的液晶区间为272~388oC（包含其固化温度350^oC）；液晶区间内固化的LC-PIIV膜在室温下保留液晶织构，室温下的面内λ（λ∥）与面间λ（λ⊥）分别达到2.11 W/(m·K)和0.32 W/(m·K)，明显高于液晶区间外固化的LC-PII膜的λ∥（0.77 W/(m·K)）与λ⊥（0.15 W/(m·K)）。同时LC-PIIV膜具有优异的力学性能和热性能，展现出在高发热量柔性电子领域中的应用前景。