Abrasion resistant waterborne polyurethane coatings based on dual crosslinked structure

The abrasion of materials leads to huge economic losses and resource waste. It is a common measure to protect substrates with organic coatings. To obtain a type of waterborne polyurethane coating with excellent abrasion resistance, 6,6′-(1,4-butanediyl)-bis-(1,3,5-triazine-2,4-diamine) (BBTDA) was synthesized and employed to prepare crosslinked waterborne polyurethane (CWPU). The introduction of BBTDA allows the construction of covalent bonding crosslinking and hydrogen bonding crosslinking networks, which contribute to improving the mechanical properties and wear resistance of the CWPU coatings. The effects of BBTDA content on the mechanical properties, thermal stability, water resistance and wear resistance of CWPU were researched. The test result indicated that the addition of BBTDA improved the mechanical properties and wear resistance of the CWPU coatings significantly. When the BBTDA content was 0.5 %, the tensile strength of the film reached 26 MPa, the water absorption decreased to 4.7 %, the hardness of the coating was 4H, and the abrasion value was only 0.4 mg. CWPU-0.5 coating offered the optimum combination property.