Kunpeng Ruan, Yongqiang Guo and Junwei Gu*. Liquid Crystalline Polyimide Films with High Intrinsic Thermal Conductivities and Robust Toughness. Macromolecules, 2021, 54(10): 4934-4944. 2019IF=5.918.(1區化學Top期刊)
(https://doi.org/10.1021/acs.macromol.1c00686)
AbstractLow 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。