Fanbin Meng

Boron Nitride Quasi-Nanoscale Fibers: Controlled Synthesis and Improvement on Thermal Properties of PHA Polymer

High-purity h-BN quasi-nanoscale fibers were successfully synthesized by annealing oriented fiber-like precursor, an adduct of melamine with boric acid at a ratio of 1:2 (M · 2B), under ammonia flow. A series of experiments have been conducted to obtain an optimum condition for generating nanoscale precursor for the synthesis of h-BN quasi nanofibers with an average diameter of ∼500 nm and length of several hundred micrometers, respectively. The fiber is a polycrystal composed of numerous disordered h-BN layers, with some stacking voids and defaults. In addition, the effects of BN fibers on the thermal conductivity and stability of biodegradable polyhydroxyalkanoate (PHA) have been studied. It is worth noting that with the addition of 2 wt% BN fibers, the thermal properties (thermostability and thermal conductivity) of the as-prepared composites have been influenced substantially.

Electrospun CF-PHA Nanocomposites: Effect of Surface Modifications of Carbon Fibers

Biodegradable polyhydroxyalkanoate (PHA) based polymer nanocomposite filled with nanoscale carbon fibers (CFs) were prepared by electrospinning. To enhance the processability and thermal properties of the composites, the carbon fibers were treated with chemical reagents, namely n-octanol, silane coupling agent (KH-550), and nitric acid (HNO3). The SEM result shows that the composite fibers with nitric acid treated CFs have the finest diameters and many uniform thickness distributions. All surface treatments on carbon fibers have increased the glass transition temperatures and crystallinities of the composites, with nitric acid treatment being the best. The improvements further depended on the volume fraction of the carbon fibers.