Preparation of an Aminated Lignin/Fe(III)/Polyvinyl Alcohol Film: A Packaging Material with UV Resistance and Slow-Release Function

To reduce the usage of petroleum-based plastic products, a lignin-based film material named aminated lignin/Fe(III)/PVA was developed. The mixture of 8 g lignin, 12 mL diethylenetriamine, 200 mL NaOH solution (0.4 mol & BULL;L-1), and 8 mL formaldehyde was heated at 85 & DEG;C for 4 h; after the aminated lignin was impregnated in the Fe(NO3)(3) solution, a mixture of 3 g aminated lignin/Fe(III), 7 g PVA, and 200 mL NaOH solution (pH 8) was heated at 85 & DEG;C for 60 min; after 2 mL of glycerin was added, the mixture was spread on a glass plate to obtain the aminated lignin/Fe(III)/PVA film. This film demonstrated hydrophobicity, an UV-blocking function, and a good slow-release performance. Due to the formation of hydrogen bonds between the hydroxyl groups of lignin and PVA, the tensile strength, the elongation at break, and the fracture resistance of the film were 9.1%, 107.8%, and 21.9% higher than that of pure PVA film, respectively. The iron content of aminated lignin/Fe(III)/PVA was 1.06 wt%, which mainly existed in a trivalent form. The aminated lignin/Fe(III)/PVA film has the potential to be used as a food packaging material with anti-ultraviolet light function and can also be developed as other packaging materials, such as seedling bowls, pots for transplanting, and coating films during transport.

Automated summary

In order to reduce the usage of petroleum-based plastic products, a lignin-based film material called aminated lignin/Fe(III)/PVA was developed. This film demonstrated hydrophobicity, UV-blocking function, and good slow-release performance. The aminated lignin/Fe(III)/PVA film showed higher tensile strength, elongation at break, and fracture resistance compared to pure PVA film due to the hydrogen bonding between lignin and PVA. It has the potential to be used as a food packaging material with UV-blocking function and can also be developed for other packaging applications such as seedling bowls, pots, and coating films during transport.