Waterborne polyurethane coatings capable of excellent transparency, solvent resistance and hardness, have been widely used in furniture, leather and other industries. However, waterborne polyurethane used as coatings may be inevitably damaged during long-term use, which has bad effect on their service life. Therefore, it is of great significance to prepare self-healable waterborne polyurethane coatings with high strength, as well as other new functions. In this work, a class of carboxyl-type waterborne polyurethanes (CWPU) was facilely prepared. The average hydrodynamic diameter size and dispersion index of the prepared CWPU were 56 nm and 0.219, showing uniform size distribution and stable emulsification system. The key point of this work is using polymine (PEI), whose molecular structure containing primary amine and secondary amine can form ionic bonds and hydrogen bonds with CWPU. PEI can be introduced as crosslinking agent to prepare cross-linked CWPU (WPUs). The tensile strength and the elongation at break of WPUs can arrive at 17.12 MPa and 512.25%. After self-healing at 30 °C for 24 h, the tensile strength and elongation at break of the WPUs can reach 3.26 MPa and 450.94%, respectively. Importantly, these synthesized WPUs not only have outstanding mechanical properties, but also exhibit excellent self-healing performance. Additionally, as for coatings, the visible light transmittance of prepared WPUs coatings is all higher than 75%, showing excellent optical properties. Especially, incorporating carbon quantum dots (CQs) can endow these prepared WPUs with obvious photoluminescence performance. The aforementioned functions of self-healing and photoluminescence performance have expanded the service life and application of WPUs coatings. This kind of coatings is expected to be used in plexiglass protective coating, light emitting diode, road signs, optical anti-counterfeiting and other fields.

水性聚氨酯涂料具有优异的透明性、耐溶剂性和硬度，已广泛应用于家具、皮革等行业。然而，作为涂料的水性聚氨酯在长期使用过程中不可避免地会受到损坏，从而影响其使用寿命。因此，制备具有高强度等新功能的自修复水性聚氨酯涂料具有重要意义。在这项工作中，我们很容易地制备了一类羧基型水性聚氨酯（CWPU）。制备的 CWPU 的平均流体力学直径尺寸和分散指数分别为 56 nm 和 0.219，显示出均匀的尺寸分布和稳定的乳化体系。这项工作的关键点是使用聚胺（PEI），其分子结构中含有伯胺和仲胺，可与CWPU形成离子键和氢键。PEI 可作为交联剂引入以制备交联 CWPU (WPU)。WPU 的拉伸强度和断裂伸长率可以达到 17.12 MPa 和 512.25%。在30℃下自愈24小时后，WPUs的拉伸强度和断裂伸长率分别达到3.26 MPa和450.94%。重要的是，这些合成的 WPU 不仅具有出色的机械性能，而且还表现出出色的自愈性能。此外，在涂层方面，制备的WPUs涂层的可见光透射率均高于75%，显示出优异的光学性能。特别是，加入碳量子点（CQs）可以赋予这些制备的 WPUs 明显的光致发光性能。上述自修复和光致发光性能的功能扩展了WPUs涂料的使用寿命和应用。该类涂料有望应用于有机玻璃保护涂料、发光二极管、路标、光学防伪等领域。