Interactions between PLA, PE and wood flour: effects of compatibilizing agents and ionic liquids

The differences in hydrophilicity are a main drawback for wood polymer composites (WPCs). This work aims at compatibilizing bio-derived poly(lactic acid) (PLA), high density polyethylene (PE) and wood fibers (WFs) with either functional PEs [PE-graft-maleic anhydride (MA) (Polybond 3029) or random copolymer of ethylene and glycidyl methacrylate (PE-g-GMA) (Lotader AX8840)] or trihexyl(tetradecyl)phosphonium bistriflamide ionic liquid (IL). The interactions and possible chemical reactions between PLA and functional PE or IL were studied including their mechanical properties. PE-g-GMA significantly increased elongation at break of PLA. According to scanning electron microscopy (SEM), the latter also displays good compatibility with WF. Addition of IL plastifies PLA without degrading it and improves the thermal stability of WF.