Strong, ductile and biodegradable polylactic acid/lignin-containing cellulose nanofibril composites with improved thermal and barrier properties

Currently, it is challenging to produce biodegradable polylactic acid (PLA) composite with both high strength and great ductility. In this work, lignin-containing cellulose nanofibrils (LCNF) derived from old newspaper were amalgamated with a biodegradable PLA matrix to prepare multifunctional composites with integrated strength and ductility. Owing to the lignin content of LCNF, the interfacial interaction and compatibility between LCNF and PLA matrix were improved by hydrogen bonding and van der Waals interactions, thereby the mechanical properties of PLA/LCNF composite films were successfully enhanced. After blending LCNF with PLA, the prepared PLA/LCNF composite films exhibited excellent UV-shielding, water vapor barrier performance, and good thermal stability. This study reveals a feasible strategy to design full biodegradable multifunctional composite using the green LCNF and biodegradable PLA.