Biobased thermosetting polymers have attracted interest owing to their renewable source materials, long service life, and properties comparable to those of petroleum-based materials. However, the fabrication of those that merge exquisite mechanical properties with fast self-healing performance has not been demonstrated to date. In this work, a biobased polyurethane coating was constructed using curcumin dioxime (CD), castor oil (CO), and isophorone diisocyanate (IPDI) to fulfill these features. The biobased CD monomer was prepared using curcumin and hydroxylamine hydrochloride and confirmed by nuclear magnetic resonance, flourier-transform infrared (FT-IR) spectra, and high-resolution mass spectrometry (HR-MS). To investigate the correlation between the mechanical properties and self-healing performance, a series of polyurethane coatings were fabricated by varying the ratio of CO to CD. The results showed that the crosslinking density (v_e), glass transition temperature (T_g), and Young modulus of these coatings increased with the decrease in the ratio of CO to CD, leading to tunable mechanical properties. In particular, the tensile strength and elongation of the COPU-4 coating were as high as 17.2 MPa and 295 %, respectively. The stress relaxation experiments revealed that these coatings exhibited low activation energy ($E_a$), as low as 28.3 kJ/mol for COPU-5. Besides, all COPU-X coatings demonstrated self-healing efficiency higher than 71 % within 1 min at 90 °C, and some of them even reached >90 % after 8 min. The results demonstrate the promising tunable mechanical and excellent self-healing properties of these novel biobased polyurethane coatings and pave the way for the development of bioderived sustainable thermosetting polymers.

生物基热固性聚合物因其可再生原料、较长的使用寿命以及与石油基材料相当的性能而引起了人们的兴趣。然而，迄今为止，将精致的机械性能与快速自愈性能相结合的材料的制造尚未得到证实。在这项工作中，使用姜黄素二肟（CD）、蓖麻油（CO）和异佛尔酮二异氰酸酯（IPDI）构建了生物基聚氨酯涂料来实现这些特性。生物基CD单体使用姜黄素和盐酸羟胺制备，并通过核磁共振、傅里叶变换红外（FT-IR）光谱和高分辨率质谱（HR-MS）证实。为了研究机械性能和自修复性能之间的相关性，通过改变 CO 与 CD 的比例制备了一系列聚氨酯涂层。结果表明，这些涂层的v_e)、玻璃化转变温度 (T_g) 和杨氏模量特别是拉伸强度COPU-4涂层的抗拉强度和伸长率分别高达17.2 MPa和295%。应力松弛实验表明这些涂层表现出低活化能（${乙}_A$），COPU-5 低至 28.3 kJ/mol。此外，所有COPU-X涂层在90℃下1分钟内的自修复效率均高于71%，其中一些涂层在8分钟后甚至达到>90%。结果证明了这些新型生物基聚氨酯涂料具有良好的可调节机械性能和优异的自修复性能，并为生物源可持续热固性聚合物的开发铺平了道路。