Enhancing thermal conductivity and near-infrared radiation reflectance of poly(ε-caprolactone)/poly(lactic acid)-based nanocomposites by incorporating hexagonal boron nitride

This work aims to develop multifunctional biodegradable ternary nanocomposites with heat dissipation capability. The effects of adding hexagonal boron nitride (hBN), regarding phase morphology, near-infrared radiation (NIR) reflectance and thermal conductivity of poly(epsilon-caprolactone) (PCL) and poly(lactic acid) (PLA) blends were investigated. The hBN nanoparticles were selectively localized in the PCL phase. Scanning electron microscopy showed that the increased hBN concentration in the PCL/PLA blend led to a more fibrillar PLA phase and, after compression molding, its morphology presented a co-continuous structure. Adding hBN nanoplatelets increased the reflectance in the NIR region by 184%, the thermal conductivity of the PCL/PLA by 400%, and increased the blend's thermal stability. The co-continuous morphology could favor the heat flow, because it promotes the confinement of the hBN nanoplatelets in the PCL phase, favoring the conductive thermal pathway formation. POLYM. COMPOS., 40:3464-3471, 2019. (c) 2019 Society of Plastics Engineers