Characteristics of bioepoxy based on waste cooking oil and lignin and its effects on asphalt binder

Abstract

Epoxy asphalts are specialty high performance binders that are composed of expensive petroleum-based bisphenol A type epoxies. In this study an environmentally friendly bioepoxy resin is used to modify the asphalt binder. The bioepoxy resin is composed of a waste cooking oil-based epoxy (WCO-EP) and a Kraft lignin-based polycarboxylic acid (KL-COOH) curing agent. Nadic methyl anhydride (NMA) is used as a co-curing agent to adjust the processability of the epoxy. The effects of the KL-COOH/NMA molar ratio on the dynamic mechanical properties, and thermal stability of the cured bioepoxy were investigated. Results show that higher ratios of KL-COOH/NMA resulted in enhanced mechanical properties of bioepoxy resin. In addition, the Multiple Stress Creep Recovery (MSCR) and Dynamic Shear Rheometer (DSR) tests were used to evaluate the high temperature performance of bioepoxy modified asphalt binders. These results show that addition of bioepoxy considerably improved the rutting resistance of asphalt binder. In addition, Bending Beam Rheometer (BBR) test was utilized to evaluate the low temperature resistance of the bioepoxy modified asphalt binder. Although the addition of bioepoxy increased the stiffness of asphalt binder, its negative effect on the thermal cracking resistance is found to be negligible.