Colloidal lignin nanoparticles from acid hydrotropic fractionation for producing tough, biodegradable, and UV blocking PVA nanocomposite

作者：Wang, Huihui; Tang, Xiaoyan; Arvanitis, Matthew A.; Yang, Vina; Stark, Nicole; Liu, Chuanfu; Considine, John M.; Zhu, J. Y.^*

来源：INDUSTRIAL CROPS AND PRODUCTS, 2021, 168: 113584.

DOI：10.1016/j.indcrop.2021.113584

• Lignin nanoparticles (LNPs)
• Colloidal LNP
• Composite film
• Toughness
• Biodegradability
• UV blocking

Colloidal lignin nanoparticles (LNPs) from low temperature acid hydrotropic fractionation (AHF) of poplar wood and commercial alkali lignin using p-Toluenesulfonic acid (p-TsOH) were directly mixed with PVA to make PVA/ AHF-LNP nanocomposite films. p-TsOH itself acted as a plasticizer for PVA; however the application of p-TsOH alone reduced PVA film tensile strength and therefore toughness. At proper loadings of LNPs and p-TsOH, both the failure strain and tensile strength of PVA/AHF-LNP composites were improved. The formation of hydrogen bonding between the p-TsOH/AHF-LNP aggregates with hydroxyl groups on PVA molecular chains, and the breakage and reforming of p-TsOH/AHF-LNP aggregates, along with the nanophase crazing due to the presence of p-TsOH/AHF-LNP aggregates were identified as the main mechanisms for improving the toughness of PVA/ AHF-LNP nanocomposite. The composite also had improved UV shielding performance and biodegradability due to the presence of p-TsOH and LNPs compared with neat PVA. This nanocomposite film could be used as biodegradable anti-ultraviolet packing film.