Synthesis of a novel bio-based curing agent and the curing behavior of the corresponding epoxy asphalt system

Abstract

Traditional epoxy asphalt is made from petroleum resources. However, petroleum-based materials may cause environmental pollution and are not renewable. In this study, a bio-based curing agent MYM was synthesized from Maleic anhydride and Myrcene. The cured epoxy EP/MYM with the weight ratio of 1:1 were prepared. When preparing the modified asphalt, carboxyl-terminated liquid nitrile butadiene rubber (CTBN) was incorporated into the EP/MYM system to obtain the EP/MYM/CTBN modified asphalt system (referred to EMC epoxy asphalt). Firstly, the chemical structure of MYM was characterized using Fourier transform infrared spectroscopy (FTIR). Secondly, the mechanical properties and thermal stability of the cured EP/MYM were investigated by tensile test and thermogravimetric analysis (TG). Thirdly, the novel EMC epoxy asphalt was prepared and its composition was optimized. The curing behavior of the EMC epoxy asphalt was investigated by differential scanning calorimetry (DSC). And the time-temperature-transition diagrams (TTT diagrams) were plotted to determine the optimal curing process. Then the surface micro-morphology of EMC epoxy asphalt was investigated by atomic force microscopy (AFM). Finally, the high-temperature viscoelastic properties of EMC epoxy asphalt were investigated using dynamic shear rheology (DSR) tests. The results showed that EP/MYM has better mechanical strength and more excellent flexibility than those of EP/MTHPA and EP/MHHPA. The weight ratio of EP:MYM:CTBN was 10:8:1.5, and the optimal amount of diluent was 8 % of the total weight of the modifier. The semi-empirical kinetic modes of curing reaction were used to plot the TTT diagram of EMC epoxy asphalt, thus determining its curing technique as 120℃/2 h+160℃/3 h. The cured EMC epoxy asphalt showed uniform alternation of light and dark areas in the AFM images, indicating good compatibility and stability. The high-temperature deformation resistance of EMC epoxy asphalt was significantly improved compared to the base asphalt. The novel epoxy asphalt system prepared in this research provides a new route for the development of echo-friendly epoxy asphalt.