In this work, lignin-decorated ZnO (QAL/ZnO) composites were prepared via an in-situ synthesis method using industrial alkali lignin (AL). Firstly, the AL was modified by quaternization to prepare quaternized alkali lignin (QAL). The microstructure and optical properties of the QAL/ZnO composites were characterized by scanning electron microscope (SEM), Transmission electron microscopy (TEM), X-ray diffraction (XRD), UV-Vis and photoluminescence (PL), respectively. It showed that the prepared QAL/ZnO composites possessed a flower-like structure and showed excellent synergistic UV-absorbent property. Interestingly, the anti-UV performance and mechanical properties of the polyurethane (PU) were significantly improved when blended with the resulting QAL/ZnO. Comparing with pure PU film, the UV transmittance of the PU film was rapidly reduced. Furthermore, the tensile strength and elongation at break of PU film blended with QAL/ZnO were significantly improved, which was due to the good compatibility between QAL/ZnO and PU matrix. Results of this work provided a significant and practical approach for the high value-added utilization of lignin as functional materials.
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