In this work, polylactide (PLA) was loaded with wood flour (WF) or hazelnut shells (HSs) (10% and 20% of fillers). The matrix and biocomposites were fully characterized from a mechanical and rheological point of view to test their processability and mechanical performance. Compost burial degradation test (30 days), with or without a prior photo-oxidation step, assessed their biodegradability after an outdoor application, and was monitored by weight loss (WL). The viscosity of the biocomposites was lower than that of the matrix and this unusual result can be attributed to a limited adhesion between the PLA and fillers. Both fillers increased the elastic modulus but decreased the tensile strength and elongation at break. As for the weathering, the degradation of PLA was mostly due to hydrolytic chain scission due to the presence of humidity. Resistance of PLA to UV irradiation improved in presence of both the two fillers. Their lignocellulosic nature was responsible for this behavior. Both fillers induced a high resistance and lower degradation in compost: WL percentages of virgin PLA was about 26%, biocomposites with 20% of WF or HS showed WL of about 10% and 14%, respectively. Photo-oxidation (36 h with condensation cycle) increased the compost degradation rate of both biocomposites and WL of PLA with 20% of WF or HS were about 15% and 21%, respectively, after 30 days.Highlights Poor adhesion between the matrix and fillers reduced the biocomposites viscosity. Fillers increased the elastic modulus but decreased the properties at break. Both fillers improved the resistance of PLA to UV irradiation. Biocomposites showed a lower susceptibility to compost degradation than PLA. Photo-oxidation increased the compost degradation rate of biocomposites. A biocomposites studying from the cradle to the grave. image
Developing biodegradable polyurethane (PU) materials as an alternative to non-degradable petroleum-based PU is a crucial and challenging task. This study utilized lactide as the starting material to synthesize polylactide polyols (PLA-OH). PLA-based polyurethanes (PLA-PUs) were successfully synthesized by introducing PLA-OH into the PU molecular chain. A higher content of PLA-OH in the soft segments resulted in a substantial improvement in the mechanical attributes of the PLA-PUs. This study found that the addition of PLA-OH content significantly improved the tensile stress of the PU from 5.35 MPa to 37.15 MPa and increased the maximum elongation to 820.8%. Additionally, the modulus and toughness of the resulting PLA-PU were also significantly improved with increasing PLA-OH content. Specifically, the PLA-PU with 40% PLA-OH exhibited a high modulus of 33.45 MPa and a toughness of 147.18 MJ m-3. PLA-PU films can be degraded to carbon dioxide and water after 6 months in the soil. This highlights the potential of synthesizing PLA-PU using biomass-renewable polylactide, which is important in green and sustainable chemistry.