Cardanol-lignin-based epoxy resins: Synthesis and characterization

The synthesis of cardanol-lignin-based epoxy resins by the reaction of epichlorohydrin (ECH) with cardanol-lignin (CL) in the presence of KOH as a catalyst has been investigated. The epoxidation reaction was found to be dependent on the cardanol content in CL. The characteristics of the obtained cardanol-lignin-based epoxy resins (CLE) were controlled by IR and C-13 NMR spectra. The characterization of the films prepared from the epoxy resins, such as glass transition temperature, T-g, and mechanical properties, have also been determined The results indicate that the increase of the cardanol content increases the tensile strength and young modulus of the film products-and decreases the T-g of the samples from CLE1 to CLE4 and then increases in the samples of CLE5 and above.