Liquid crystalline texture and hydrogen bond on the thermal conductivities of intrinsic thermal conductive polymer films

Polymer-dispersed liquid crystal (PDLC) films comprising polyvinyl alcohol (PVA) and liquid crystal monomer (LCM) were successfully obtained by the method of solution casting & thermal compressing. LCM was distributed orderly in PVA matrix by hydrogen bond interaction, to form PVA-LCM interpenetrating-layered networks. When the mass fraction of LCM was up to 35 wt%, the corresponding in-plane thermal conductivity coefficient (lambda//) of PDLC film was significantly increased to 1.41 W m(-1) K-1, about 10.8 times that of neat PVA (0.13 W m(-1) K-1). High intrinsic lambda// values of PDLC films were mainly attributed to the formed microscopic-ordered structures from ordered stacking of LCM, ordered arrangement of PVA chains, and their hydrogen bond interaction. This work would offer a new way to design and prepare novel intrinsic high thermal conductive polymers. (C) 2021 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Automated summary

PDLC films composed of PVA and LCM were successfully prepared by solution casting & thermal compressing method, showing significantly improved thermal conductivity compared to neat PVA due to the hydrogen bond interaction between LCM and PVA. The high thermal conductivity of PDLC films was mainly attributed to the ordered structures formed by LCM stacking, PVA chain arrangement, and their hydrogen bond interaction, providing a new approach for designing and preparing novel high thermal conductive polymers.