Polyamides (PAs) are widely utilized in the textiles and automotive industry due to their high durability and strength. However, the inherent low thermal conductivity limits its usage, especially as electronic devices. For higher thermal conductivity, the strategy to add thermal-conductive particles such as BN in polymer matrix has been employed. The resultant conductive network in the composites depends on the shape, concentration, and alignment of the particles. In this work, demethylated lignin with enhanced polyphenol structure was prepared and dissolved in an aqueous solution at pH=13. The negative charged functional groups of demethylated lignin along with the free OH<sup>-</sup> in the solution helps exfoliate the h-BN and stabilize the exfoliated nanosheets during ultrasonic treatment. The hybrid particles of demethylated-lignin/h-BN were then blended with PA 12 for filament and 3D-printed on a fused depositional modeling (FDM) printer. The printed samples showed an improved thermal conductivity compared to that of PA 12. In addition, along with the interaction between demethylated lignin and PA 12, the printable polymer composites with enhanced thermal conductivity can remain comparable tensile properties as pure PA by adding extra demethylated lignin, which makes the potential of the composite in printing structure-complex electrical devices.

3D printing of polymer composites with lignin-assisted-exfoliated boron nitride (BN) for enhanced thermal conductivity

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.