Influenceof Microscopic Ordered Arrangement and High-Voltage Directional Molding in Epoxy Liquid Crystal Dispersed Membranes on Intrinsic Thermal Conductivity

Abstract

Flexible epoxy liquid crystal dispersed membranes (ELCMs) with high thermal conductivity (TC) were successfully prepared by using high-voltage directional molding. Epoxy liquid crystal monomers (Epoxy-LC1 and Epoxy-LC2) were uniformly dispersed into flexible epoxy polymers cured by pentaerythritol tetra (3-mercaptopropionate). TC of ELCM1 and ELCM2 reached 1.27 W·(m·K)−1 and 2.36 W·(m·K)−1 with 30 wt% content of Epoxy-LC1 and Epoxy-LC2, which were 4.5 times and 8.43 times higher than that of pure epoxy polymer, respectively. Tensile strength and elongation at break of ELCM1 and ELCM2 were up to 8.1 MPa, 23 % and 23.8 MPa, 46.7 %, respectively. On the one hand, the favorable results are attributed to the molecular chains’ microscopic ordered arrangement by using high-voltage directional molding. On the other hand, the more important reason is that the hydrogen-bond interactions between -C=O and -OH of molecular chains in Epoxy-LC2 and epoxy polymer. This work offers a new way to design flexible epoxy resins and intrinsic thermal conductive polymers.

Keywords: Epoxy liquid crystal monomer, Intrinsic thermal conductivity, Microscopic ordered arrangement, High-voltage directional molding, The uniform layered structures, The dense scaly structures