Fabrication and characterization of cellulose/ lignin microspheres films with UV-blocking

With the rapid development of packaging industry and the improvement of environmental protection requirements of human society, biodegradable functional packaging film materials have attracted great attention. However, commercial biodegradable functional package film materials have been constrained by its high cost, low mechanical properties and water resistance. The lignin microspheres were firstly prepared by self-assembling and were adhered to the surface of cellulose film <i>via</i> self-depositing, resulting in fabrication of novel cellulose-based UV-blocking film materials. Subsequently, the surface morphology, ultraviolet resistance and mechanical properties of the obtained functional film materials were studied. The surface properties of films were investigated by scanning microscopy (SEM),infrared spectroscopy (FTIR) and confocal laser scanning microscopy.The mechanical properties and UV resistance of cellulose based films were characterized by tensile test and UV transmittance test.It is noteworthy that the lignin microspheres with 1-2 μm in size are uniformly distributed on cellulose films and hydrophobic modification of cellulose-based films facilitated the deposition of lignin. Moreover, the deposited contents of lignin microspheres increase with the increase of the lignin concentration in solution. Due to the introduction of lignin microspheres, the strength of cellulose composites film increases by 22% and the UVB-shielding capacity reaches 94% as compared with the controlled cellulose films.