Current pavement marking materials (PMMs) have good durability but lack repairability and are difficult to remove requiring costly environmentally hazardous energy-intensive techniques to remove them for replacement. A solution is vitrimers, a class of thermosetting polymers, that retain good durability of thermosets and also allow for self-healing at elevated temperatures. This research was aimed at developing a vitrimer two-part epoxy pavement marking material that can self-heal micro-cuts and is selectively removable in a mild acidic solution. This vitrimer -based material was made by synthesizing Schiff base diamine (SBDA) epoxy curing agents containing dynamic bonds. Novel formulations that met durability and curing rate requirements were then developed by mixing the SBDAs with commercial polyamines, dual curing with acrylates, creating an adduct crosslinker, and adding a hardener to increase the reactivity. The properties of promising formulations were confirmed using DOT standards for hardness, curing rate, and abrasion resistance while ensuring that they retained their self-healing properties and selective removability in mildly acidic solutions. The formulations were then applied at the North Dakota State University campus, the MnROAD low-volume test track, and MnROAD I-94 test section. The formulations performed on par or better than commercial formulations in coverage after 6-12 months on new concrete and hot melt asphalt (HMA). A life-cycle cost analysis found the raw chemicals used in the novel material could potentially cost 13-17% more than the commercial two-part epoxy markings but would need to be replaced less often and also decrease labor costs and road downtime. It was also found that the developed formulation would be less expensive than commercial temporary marking materials when operating in its dual-purpose role. Further research on the topic will focus on reducing the synthesis and material costs, improving the self-healing efficiency, and further developing the removal process by synthesizing the material on-site, allowing for greater control over the material's properties.
The final report is available.