15 - Biodegradable biosourced epoxy thermosets, blends, and composites

Abstract

Bio-epoxies, their blends, and composites derived from renewable resources have received considerable attention in recent years due to their characteristics of being light weight, high toughness, excellent viscoelastic properties, easy processing, environment friendliness, and most importantly biodegradable potential. Epoxy is the most important thermoset polymer because of its unique properties. Many biorenewable resources like plant oil, cardanol, lignin, furan, rosin, eugenol, etc. have been chemically modified to form epoxy prepolymers, of which some resins have shown comparable or even greater properties with petro-based epoxy on curing. Further, the inherent brittleness, higher cost, toxic nature, and processability issues of epoxy limit its wide application in polymer and composite industries. Recently, many bioresins have overcome the brittleness and toughened the matrix effectively with moderate mechanical and thermal properties and higher damping ability. Reinforcement of natural fibers within the bioresin toughened epoxy blend is a suitable method to maintain the stiffness–toughness balance. Natural fibers with high strength and stiffness and an inherent eco-friendly nature are capable of reinforcing the polymer matrix to produce composites with the desired attributes. This chapter is based on recent developments in the design, synthesis, and preparation of novel sustainable epoxies with higher biosource content with biodegradation potential meant for industrial applications.