Preparation of Highly Reactive Lignin by Ozone Oxidation: Application as Surfactants with Antioxidant and Anti-UV Properties

Abstract

Enhancement of lignin reactivity plays a critical role in the chemical modification of lignin. In the current study, a simple, green, and effective method, of ozone oxidation, was developed to improve the reactivity of enzymatic lignin through the formation of carboxyl groups. The resultant ozonate of enzymatic lignin (OzEL) indicated a higher reactivity of esterification. The ozonated enzymatic lignin grafted to polyethylene glycol (OzEL-PEGs) afforded satisfactory water solubility, good surface activity, and good emulsifying properties. The remaining phenolic hydroxyl groups in OzEL-PEGs also maintain excellent antioxidant and UV absorbing properties. This ozone oxidation process provides an effective and green method for the preparation of highly reactive lignin, which can be applied in the manufacture of a multifunctional lignin polymer.

Lignin as a UV Light Blocker—A Review

“…An enzymatic lignin product modified with ozone oxidation grafted with polyethylene glycol was reported to exhibit excellent antioxidant and UV absorbing properties in the UVA and UVB spectral region [34]. The ozone oxidation process provided an effective and green method for the preparation of highly reactive lignin, which can be applied in the manufacturing of a multifunctional lignin polymer.…”

Nonleachable Antibacterial Nanocellulose with Excellent Cytocompatible and UV-Shielding Properties Achieved by Counterion Exchange with Nature-Based Phenolic Acids

“…As shown in Table S1, the UVA (400−320 nm), UVB (320−280 nm), and UV (200−400 nm) blocking percentages and the ultraviolet protection factor (UPF) of the PCA-Q-NFC1.0 film were 94.1%, 99.9%, 97.7% and 304, respectively, which were significantly higher than those (that is 20.0%, 28.1%, 33.9%, and 1) of the Q-NFC1.0 one. This should be attributed to chromophores (unsaturated groups, i.e., benzene ring, carbonyl, and vinyl groups) and auxochromes (groups with lone pairs of electrons, i.e., phenolic hydroxyl) 53 in the attached PCA moieties. Briefly, the chromophores could adsorb lights with a fixed wavelength and exert a protective effect via the n → π* and π → π* transitions.…”

Recent Developments in the Formulation and Use of Polymers and Particles of Plant‐based Origin for Emulsion Stabilizations

“…Lignin‐PEO [poly(ethylene oxide)] was successfully used for the emulsion polymerization of styrene, while that with a lower M w demonstrated higher stabilizing efficiency [174] . Similarly, the surface activity (surface tension decline) and emulsifying properties of ozone oxidized‐PEGylated (polyethylene glycol) lignin derivatives were dependent on the length of grafted PEG, as the medium DS showed the better properties [175] …”