Preparation
of Highly Thermally Conductive Polymer Composite at Low Filler Content
via a Self-Assembly Process between Polystyrene Microspheres and Boron Nitride Nanosheets
posted on 2017-05-23, 00:00authored byXiongwei Wang, Peiyi Wu
Rational distribution
and orientation of boron nitride nanosheets (BNNSs) are very significant
for a polymer/BNNS composite to obtain a high thermal conductivity
at low filler content. In this paper, a high-performance thermal interface
material based on exfoliated BNNSs and polystyrene (PS) microspheres
was fabricated by latex blending and subsequent compression molding.
In this case, BNNSs and PS microspheres first self-assembled to form
the complex microspheres via strong electrostatic interactions between
them. The as-prepared complex microspheres were further hot-pressed
around the glass transition temperature, which brought the selective
distribution of BNNSs at the interface of the deformed PS microspheres.
As a consequence, a polymer composite with homogeneous dispersion
and high in-plane orientation of BNNSs in PS matrix was obtained.
Benefitted from this unique structure, the resultant composite exhibits
a significant thermal conductivity enhancement of 8.0 W m–1 K–1 at a low filler content of 13.4 vol %. This
facile method provides a new strategy to design and fabricate highly
thermally conductive composites.