Ecofriendly UV-protective films based on poly(propylene carbonate) biocomposites filled with TiO2 decorated lignin

It is highly desirable to develop biodegradable UV-shielding materials from the renewable resources as the ever-increasing demand for the sustainable environment. In this work, TiO2 decorated lignin particles (TiO2@lignin) were synthesized successfully by hydrothermal method in aqueous solution to improve the UV shielding performance of lignin particles. The poly(propylene carbonate) (PPC) composite films (thickness of ~23 μm) with different contents of TiO2@lignin were prepared via a blade-casting method. Morphological analysis showed that the TiO2@lignin dispersed uniformly in the PPC matrix with a good miscibility. UV–vis transmission spectra results revealed that the PPC composite film containing 5 wt% TiO2@lignin could absorb about 90% of UV light in the full UV band (200–400 nm), indicating the TiO2@lignin had a good UV-shielding property. Moreover, the presence of TiO2@lignin could significantly improve the thermal stability of the PPC/TiO2@lignin composite films. The DMA results showed that the introduction of TiO2@lignin could enhance the storage modulus and glass transition temperature simultaneously.