Enhanced intrinsic thermal conductivity of liquid crystalline polyester dispersed films through hydrogen bond interaction

Polymer-dispersed liquid crystal (MHxFy) films comprising liquid crystal polymer (LCPH and LCPF) were successfully obtained by the method of solution casting & thermal compressing. At a LCPH mass fraction of 67 %, thermal conductivity (λ) value in through-plane (λ ⊥ ) and in-plane (λ ∥ ) direction of MH 2 F 1 films reach up to 0.305 W/(m·K) and 2.879 W/(m·K), respectively. In comparison to pure LCPF, the thermal conductivity of MH 2 F 1 exhibited an increase of 4.42 times, which is 14.4 times than that of conventional thermoplastics. Meanwhile, the crystallinity of MHxFy films around 50 % which is indicate the crystal phase become more integrated and regular. The FTIR spectra reveals a significant blue shift (3432 cm −1 to 3421 cm −1 ) in the absorption peak of the –OH group in MH 2 F 1 , suggesting a robust interaction between LCPF and LCPH. The primary cause of elevated thermal conduction in these films was determined to be the consistent presence of “thermal bridges” and a high degree of crystallinity. Furthermore, the T 5% , T max and residual carbon at 800 °C of MH 2 F 1 were 347.8 °C, 409.4 °C and 8 %, respectively. This is attributed to the ordered distribution of LCPH in LCPF matrix through hydrogen bonding interaction, forming an interpenetrating network of LCPF-LCPH. The result show that MHxFy films demonstrating superior intrinsic thermal conductivities, thermal stabilities, and mechanical properties.