Application of bioethanol derived lignin for improving physico-mechanical properties of thermoset biocomposites

• Lignin from ethanol production can serve as a functional filler in thermoset composites.
• Type of lignin and loading fraction level can help to design and engineer composite properties.
• Addition of 15% wheat or corn stover bioethanol lignin shows minimal impact on mechanical properties of epoxy based composites.
• Impact strength of epoxy based composites can be improved by addition of lignin.
• Lignin can improve the thermal stability of epoxy composites through barrier effect.

Lignin is the most abundant of renewable polymers next to cellulose with a global annual production of 70 million tons, largely produced from pulping and second generation biofuel industries. Low value of industrial lignin makes it an attractive biomaterial for wide range of applications. The study investigated the application of wheat straw and corn stover based lignin derived from ethanol production for use in thermoset biocomposites. The biocomposite matrix constituted a two component low viscosity Araldite®LY 8601/Aradur® 8602 epoxy resin system and the lignin content varied from 0 to 25% by weight fraction. The analysis of the physical and mechanical properties of the biocomposites show bioethanol derived lignin can improve selective properties such as impact strength, and thermal stability without compromising the modulus and strength attributes.