Enhanced thermal conductivity of polyimide films via a hybrid of micro- and nano-sized boron nitride.
A new thermally conductive polyimide composite film has been developed. It is based on a dispersion of different particle sizes of boron nitride (BN) in a polyimide (PI) precursor, polyamic acid (PAA). Subsequently, thermal imidization of PAA at 350 degrees C produced the corresponding polyimide composites. 3-Mercaptopropionic acid was used as the surfactant to modify the BN surface for the dispersion of BN in the polymer. The PI/BN composites showed different thermal conductivities at different proportion of BN particle sizes and contents. The thermal conductivity of the PI/BN composite was up to 1.2 W/m-k, for a mixture containing 30 wt % of micro and nanosized BN fillers in the polyimide matrix. The PI/BN composites had excellent thermal properties. Their glass transition temperatures were above 360 degrees C, and thermal decomposition temperatures were over 536 degrees C.
Li
Tung-Lin
TL
Department of Materials Science and Engineering, Center for Micro/Nano Science and Technology, National Cheng-Kung University, No.1, University Road, Tainan City 701 Tainan, Taiwan, ROC.
Hsu
Steve Lien-Chung
SL