Innovative structural modification process of Kraft lignin using continuous-flow regime

An innovative process for the structural modification of kraft lignin (KL), followed by the incorporation of the herbicide picloram (PCL; C6H3Cl3N2O2; CAS, 1918-02-1) to obtain a nanoformulation, was developed by means of a hydroxymethylation reaction in a continuous-flow regime to reach the technological readiness level (TRL) 4. The modified KL-PCL nanoformulation obtained should be used to validate formulations for the controlled release of the herbicide in the subsequent stage (TRL5) to prove the environmental benefit of this type of formulation against a conventional formulation. It is expected that structural modification will improve properties such as surface area, adsorption, and the availability of chemical groups for interaction. The developed modification process proved to be more efficient because it was performed with a reaction time 12 times shorter on average than the same reaction already described in the literature, and the nanoformulation resulting from the continuous-flow processing showed an excellent polydispersity index compared to the batch method. The modification process, which uses flow synthesis and includes the incorporation of an agrochemical molecule, not only represents an innovative approach but also aligns with the United Nations Sustainable Development Goals.