Intrinsic high thermal conductive liquid crystal epoxy film simultaneously combining with excellent intrinsic self-healing performance. (30th March 2021)

• Record Type: Journal Article
• Authors: Yang, Xutong; Zhong, Xiao; Zhang, Junliang; Gu, Junwei
• Is Part Of: Journal of materials science & technology. Volume 68(2021)
• Page Start: 209
• Page End: 215
• Publication Date: 2021-03-30
• Subjects: Liquid crystal epoxy -- Self-healing performance -- Intrinsic thermal conductivity -- Thermal stability; Metals -- Periodicals; Materials science -- Periodicals; Materials science; Metals; Periodicals; 620.1105
• DOI: 10.1016/j.jmst.2020.08.027
• Languages: English
• ISSNs: 1005-0302

Abstract

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. 1 H 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.