Low-Density Polyethylene/Poly(Lactic Acid) Blends Reinforced by Waste Wood Flour

The main purpose of this work was the valorization of waste wood flour as reinforcement in order to develop new wood-based polymer composites (WBPCs). For that purpose, low-density polyethylene/poly(lactic acid) (LDPE/PLA) blends were prepared in presence of poly(ethylene-co-glycidyl methacrylate) (PE-g-GMA) as compatibilizer and reinforced with 0-40 wt% of wood flour. The tensile properties, Charpy impact strength, morphology, and thermal properties (differential scanning calorimetry (DSC) and thermogravimetric analysis [TGA, DTG]) of the LDPE/PLA/PE-g-GMA (20/80/5) composites were characterized. The results showed that Young's modulus increased with increasing the wood flour content and the composites are brittle. Globally, stress at break, elongation at break, and Charpy impact decreased with increasing the content of wood flour. Morphological investigation revealed a good interfacial adhesion between LDPE/PLA/PE-g-GMA blend and wood flour. The stability of composites was affected by the incorporation of 10 wt% of wood flour and varied slightly with the increase in load. The values of speed of maximal weight loss of the composites were lower than that obtained for the blend without wood flour. The dispersion of wood flour decreased the onset degradation temperature of PLA, while the rate of thermal degradation of composites was improved. On the other hand, the degree of crystallinity of composites increased by the addition of wood flour indicating the possibility that wood flour can act as nucleating agent. Finally, the water absorption of the composites depends on the immersion time, the nature, and the content of the load. J. VINYL ADDIT. TECHNOL., 2020. (c) 2020 Society of Plastics Engineers