Affiliation:
1. Coal and Energy Division CSIR‐North East Institute of Science and Technology Jorhat India
2. Academy of Scientific and Innovative Research (AcSIR) Ghaziabad India
3. Materials Sciences and Technology Division CSIR‐North East Institute of Science and Technology Jorhat India
Abstract
AbstractThe recent advancements on the development of sustainable copolymers from lignin, has led us to explore a novel two‐step methodology for the development of lignin‐derived copolymers for flexible film preparation. In this work, firstly, chemical modification of lignin with itaconic acid (IA) in green solvent followed by grafting with lactic acid (LA) via solvent free polycondensation pathway was used to produce Lig‐g‐PLA copolymers. The effect of various reaction parameters like IA and LA amount, reaction time, solvent, temperature was studied to optimize yield of the reaction. Analytical techniques (FT‐IR, NMR, and XPS) confirmed successful chemical modification of lignin and copolymer (Lig‐g‐PLA) synthesis. The change in flexibility behavior of the polymer thin films (250 microns) prepared through hydraulic hot press method found to be dependent on the LA grafting. Notably, smooth surface of the films prepared with LA amount (IAL:LA 1:3 wt ratio) indicates enhanced compatibility between copolymer molecules due to the grafting of LA. Additionally, films prepared with a higher LA amount (i.e., IAL:LA 1:4 wt ratio) exhibited superior mechanical property with 3 times higher storage modulus as compared to the film prepared with lower LA amount (i.e., IAL:LA 1:2 wt ratio).