par Noukaze, Laurette 
Président du jury Cannella, David
Promoteur Gonçalves, Thiago Augusto
Publication Non publié, 2023-08-28
Président du jury Cannella, David
Promoteur Gonçalves, Thiago Augusto
Publication Non publié, 2023-08-28
Mémoire
| Résumé : | For many years, lignin has been considered as an undesirable by product until his great poten-tial was discovered and many applications based on lignin were found. Nowadays, lignin seems to be a crucial element in the transition of the world economy essentially based on non-renewable energy source to a bioeconomy which will be based on renewable energy source. For instance, lignin can be used as an alternative feedstock in the production of biofu-els, biopolymers, biochemicals aromatics compounds and many others. Despite the numerous investigations that have been done to study and characterize lignin on very detailed ways this last decades, a certain number of things remain unknow such as the biosynthesis pathways, the lignin native structure and a full characterization of lignin. So many efforts keep being done to fill the gaps. Currently, graft copolymerization of polysaccharides has become the most used technique to improve the polysaccharides properties. In this work, I attempted to characterize lignin in different pH conditions but also to do an enzymatic graft copolymeriza-tion of cellulose cotton and lignin molecules. To succeed the grafting of lignin on cellulose, we first try to find the optimal conditions to have soluble lignin molecules and active laccases responsible of the grafting. UV, fluorescence, and FTIR-infrared spectroscopy have been used to characterize the lignin and the grafted cellulose cottons. |
