Molecules, Vol. 25, Pages 4921: Biocatalytic Strategy for Grafting Natural Lignin with Aniline

Molecules, Vol. 25, Pages 4921: Biocatalytic Strategy for Grafting Natural Lignin with Aniline
Molecules doi: 10.3390/molecules25214921
Authors:
Sabina Gabriela Ion
Teodor Brudiu
Anamaria Hanganu
Florentina Munteanu
Madalin Enache
Gabriel-Mihai Maria
Madalina Tudorache
Vasile Parvulescu

This paper presents an enzyme biocatalytic method for grafting lignin (grafting bioprocess) with aniline, leading to an amino-derivatized polymeric product with modified properties (e.g., conductivity, acidity/basicity, thermostability and amino-functionalization). Peroxidase enzyme was used as a biocatalyst and H2O2 was used as an oxidation reagent, while the oxidative insertion of aniline into the lignin structure followed a radical mechanism specific for the peroxidase enzyme. The grafting bioprocess was tested in different configurations by varying the source of peroxidase, enzyme concentration and type of lignin. Its performance was evaluated in terms of aniline conversion calculated based on UV-vis analysis. The insertion of amine groups was checked by 1H-NMR technique, where NH protons were detected in the range of 5.01–4.99 ppm. The FTIR spectra, collected before and after the grafting bioprocess, gave evidence for the lignin modification. Finally, the abundance of grafted amine groups was correlated with the decrease of the free –OH groups (from 0.030 to 0.009 –OH groups/L for initial and grafted lignin, respectively). Ad...

Source: Molecules - October 24, 2020 Category: Chemistry Authors: Sabina Gabriela Ion Teodor Brudiu Anamaria Hanganu Florentina Munteanu Madalin Enache Gabriel-Mihai Maria Madalina Tudorache Vasile Parvulescu Tags: Article Source Type: research