Weathering-Induced Aging of Polyethylene-Based Lignocellulosic Composites in the Context of the Circular Economy

Abstract

Polyethylene (PE)-based composites reinforced with lignocellulosic fillers undergo a gradual decline in performance under weathering conditions. This review combines a bibliometric analysis using VOSviewer 1.6.20 with a critical assessment of the literature to examine the weathering behavior of these composites and discuss its implications for the circular economy, particularly with respect to extending service life. The literature shows that mechanical property retention depends primarily on the lignocellulosic filler content (below 50 wt%), fiber-matrix interfacial adhesion, composite microstructure, and environmental exposure conditions. Because lignocellulosic fibers are inherently hydrophilic, water uptake and subsequent microcrack formation can compromise the structural integrity of the composite. Conversely, lignin present in the lignocellulosic reinforcement, coupling agents such as maleic anhydride-grafted polyethylene (PE-g-MA), and ultraviolet (UV) stabilizers such as zinc oxide enhance fiber–matrix adhesion, mitigate photo-oxidative degradation and improve the retention of mechanical properties during weathering. Although the relationship between weathering and the circular economy has rarely been explicitly addressed, the available evidence identifies the material compositions and exposure conditions that favor property retention, thereby supporting longer service life and increasing the potential for circular use of PE-based lignocellulosic composites.