Oligolignols within lignin-adhesive formulations drive their Young's modulus: A ReaxFF-MD study

Adhesive formulations based on depolymerized lignins were studied to investigate the contribution of their oligolignols content in the determination of its Young's modulus towards the contact with a cellulose surface. Four lignins with low molar mass, tested and reported in an earlier study, Were employed to model oligolignol molecular sub-structures. Over these oligolignols, several Reactive Force Field (ReaxFF) molecular dynamic simulations were considered to elucidate the contribution of each molecular structure to the adhesive capacity of the lignin mixture, modelling the interaction of each oligolignol over one model of cellulose 1-13. One important result obtained from these simulations is, that coupling energies obtained for the oligolignol-cellulose complexes correlate quite well with experimental values of Young's modulus, yielding the insight to describe how oligolignols within lignin-adhesive formulations drive their Young's modulus from an atomistic point of view. This study opens a new perspective to design novel wood adhesive formulations based on lignins, considering the oligolignols present in their composition.