[Macromolecules] Liquid Crystalline Polyimide Films with High Intrinsic Thermal Conductivities and Robust Toughness
作者：Kunpeng Ruan, Yongqiang Guo and Junwei Gu*
關鍵字：Thermally conductive composites
論文來源：期刊
具體來源：Macromolecules
發表時間：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 272~388oC, 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.
聚酰亞胺（PI）膜較低的本征導熱系數（λ）限制了其在易發熱柔性電子器件的進一步應用。通過優化調控液晶區間與固化溫度相匹配，制備出一種本征高導熱液晶聚酰亞胺（LC-PI）膜。結果表明，當4, 4’-二氨基二苯醚（ODA）和1, 4-雙（4-氨基苯氧基）苯（TPE-Q）的摩爾比為1：3時（IV號樣品），preLC-PIIV膜的液晶區間為272~388oC（包含其固化溫度350oC）；液晶區間內固化的LC-PIIV膜在室溫下保留液晶織構，室溫下的面內λ（λ∥）與面間λ（λ⊥）分別達到2.11 W/(m·K)和0.32 W/(m·K)，明顯高于液晶區間外固化的LC-PII膜的λ∥（0.77 W/(m·K)）與λ⊥（0.15 W/(m·K)）。同時LC-PIIV膜具有優異的力學性能和熱性能，展現出在高發熱量柔性電子領域中的應用前景。