Novel transparent lignin/epoxy resin nanocomposite film development with enhanced UV resistance performance

Abstract The increased importance of nanostructured lignin exhibits a plethora of multifunctional groups, making it a highly adaptable material basis with significant potential for use in the rapidly expanding composite sector. Initially, lignin nanoparticles (NPs) were incorporated into epoxy networks via an in situ polymerization process where isophorone diamine functioned as a hardener to produce lignin/epoxy resin nanocomposites (lignin@TN). These lignin@TN exhibit promising characteristics, enhancing UV‐blocking efficiency (35.69% at 404 nm with 3.72 wt% lignin) in transparent nanocomposite films while simultaneously improving mechanical properties compared with neat epoxy resin. Adding lignin nanoparticles to epoxy nanocomposites boost up tensile strength by an impressive 24% compared with the pristine epoxy but it affected the glass transition temperature ( T g ). After all, this study has opened new possibilities for utilizing renewable, sustainable, and economic lignin feedstocks as a potential ingredient for reinforcing with thermoset polymers like epoxy.