Lignin-based materials through thiol - maleimide "click" polymerization
Auteurs
P. Buono, A. Duval, L. Averous, and Y. Habibi
Référence
ChemSusChem, vol. 10, no. 5, pp. 984-992, 2017
Description
In the present work we propose an environmentally friendly approach to transform renewable feedstocks into value-added materials. This transformation pathway is conducted under green conditions, without the use of solvents and catalyst. First, controlled modification of lignin, a major biopolymer present in wood and plants, was achieved through the esterification with 11-maleimidoundecylenic acid (11-MUA), a derivative from ocastor oil that contains maleimide groups. Different degrees of substitution were achieved by using various amounts of the 11-MU acyl chloride leading to an efficient conversion of lignin hydroxyl groups as demonstrated by 1H and 31P NMR analyses. These fully biobased maleimide-lignin derivatives were reacted through an extremely fast (about one minute) thiol-ene "click" polymerization with thiol-containing linkers. Aliphatic and aromatic thiol-linkers bearing from 2 to 4 thiol groups were used in order to tune the reactivity and crosslinking density. The properties of the resulting materials were evaluated by swelling tests, thermal and mechanical analyses showing that varying the linker functionality and structure allows to accurately tailor the thermal and mechanical properties of the final materials, thus providing interesting perspectives for lignin towards functional aromatic polymers.
