J. Mater. Sci. Technol. ›› 2021, Vol. 68: 209-215.DOI: 10.1016/j.jmst.2020.08.027

• Research Article • Previous Articles     Next Articles

Intrinsic high thermal conductive liquid crystal epoxy film simultaneously combining with excellent intrinsic self-healing performance

Xutong Yanga,b, Xiao Zhongb, Junliang Zhanga,b,c, Junwei Gua,b,*()   

  1. a Research & Development Institute of Northwestern Polytechnical University in Shenzhen, Guangdong, 518057, China
    b Shaanxi Key Laboratory of Macromolecular Science and Technology, School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi’an, Shaanxi, 710072, China
    c School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang, 471023, China
  • Received:2020-05-27 Revised:2020-07-13 Accepted:2020-07-23 Published:2021-03-30 Online:2021-05-01
  • Contact: Junwei Gu
  • About author:*Research & Development Institute of Northwestern Polytechnical University in Shenzhen, Guangdong, 518057, China. E-mail addresses: gjw@nwpu.edu.cn,nwpugjw@163.com (J. Gu).

Abstract:

One kind of side chain liquid crystal epoxy (S-LCE) based on biphenyl mesomorphic unit is synthesized from 2, 2-bis(hydroxymethyl)propionic acid, 4-phenylphenol, and epichlorohydrin. And the intrinsic thermal conductive liquid crystal epoxy film (LCEF) simultaneously combining with intrinsic self-healing performance is then prepared via thiol-epoxide nucleophilic ring-opening reaction and coating method. 1H NMR and FTIR show that S-LCE and LCEF have been successfully prepared. S-LCE presents nematic liquid crystal from room temperature to 160 °C. LCEF maintains nematic liquid crystal performance and shows highly intrinsic thermal conductivity & excellent self-healing performance. Thermal conductivity coefficient (λ) values in vertical direction (λ) and parallel direction (λ//) of LCEF are 0.33 and 1.25 W/mK, respectively, much higher than that of general bisphenol A epoxy resin (E-51, λ of 0.19 W/mK and λ// of 0.65 W/mK). Tensile strength of LCEF is 10.6 MPa, which can maintain at 90.6 % and 61.3 % after one and four cycles of self-healing behavior, respectively. In addition, LCEF presents a wide service temperature range (-9.8-251 °C) and good thermal stability (THRI of 148.5 °C). Simultaneously, LCEF has good transparency, flexibility, and tailorability, expected to be utilized in the fields of flexible electronic devices and intelligent structures.

Key words: Liquid crystal epoxy, Self-healing performance, Intrinsic thermal conductivity, Thermal stability