mz8b00456_si_001.pdf (1.6 MB)
Enhanced Thermal Conductivity of Liquid Crystalline Epoxy Resin using Controlled Linear Polymerization
journal contribution
posted on 2018-09-14, 15:21 authored by Akherul
Md. Islam, Hongjin Lim, Nam-Ho You, Seokhoon Ahn, Munju Goh, Jae Ryang Hahn, Hyeonuk Yeo, Se Gyu JangA powerful strategy
to enhance the thermal conductivity of liquid
crystalline epoxy resin (LCER) by simply replacing the conventional
amine cross-linker with a cationic initiator was developed. The cationic
initiator linearly wove the epoxy groups tethered on the microscopically
aligned liquid crystal mesogens, resulting in freezing of the ordered
LC microstructures even after curing. Owing to the reduced phonon
scattering during heat transport through the ordered LC structure,
a dramatic improvement in the thermal conductivity of neat cation-cured
LCER was achieved to give a value ∼141% (i.e., 0.48 W/mK) higher
than that of the amorphous amine-cured LCER. In addition, at the same
composite volume fraction in the presence of a 2-D boron nitride filler,
an approximately 130% higher thermal conductivity (maximum ∼23
W/mK at 60 vol %) was observed. The nanoarchitecture effect of the
ordered LCER on the thermal conductivity was then examined by a systematic
investigation using differential scanning calorimetry, polarized optical
microscopy, X-ray diffraction, and thermal conductivity measurements.
The linear polymerization of LCER can therefore be considered a practical
strategy to enable the cost-efficient mass production of heat-dissipating
materials, due to its high efficiency and simple process without the
requirement for complex equipment.