(346c) Synthesis and Curing of Bio-Based Epoxy Resin Derived From Organosolv Lignin

Epoxidation of lignin is a promising way to promote its performance and develop its new application in coatings and adhesive industries. In the present work, bio-based epoxy resin was synthesized by the reaction of de-polymerized organosolv lignin with epichlorohydrin in alkaline condition and in presence of a phase transfer catalyst. The effects of reaction time, reaction temperature and sodium hydroxide/lignin ratio were investigated. A statistical optimization process was also conducted to achieve a bio-based epoxy resin with high epoxy index and low molecular weight. The obtained bio-based epoxy resins were characterized using FTIR to investigate the chemical structure of lignin and confirm the grafting of epoxy groups on the structure on lignin and gel permeation chromatography (GPC) for their molecular weights and dispersion. The curing kinetic of the synthesized epoxy resin/ Diethylenetriamine (DETA) was studied by non-isothermal differential scanning calorimetry (DSC). The kinetics of the curing reaction was evaluated by the advanced isoconversional method which is proposed by Vyazovkin to obtain the activation energies of the curing reaction as a function of the degree of cure.