Chongqing, China – Self-emulsification and dual dynamic bonds have been used to extend the lifespan of polyurethane-modified emulsified asphalt. Scientists at Chongqing Jiaotong University’s school of material science and engineering prepared a recyclable PU incorporating disulfide bonds and hydrogen bonds, which confer self-healing and regeneration properties.
They used particle dispersion and zeta potential tests to show that both the PU and the modified asphalt had good dispersion and stability properties. Microscopic and thermal analysis showed that the PU had dynamic bonds, remaining thermally stable below 250°C.
The PU gave the modified asphalt a strong physical cross-linking network, and a stress–strain healing efficiency of more than 73%. They concluded that the disulfide and hydrogen bonds in the PU conferred regenerative properties, and self-healing capabilities to the modified asphalt.
The work has been published in the journal Science of the Total Environment.
