Abstract: This paper introduces a comprehensive applied chemistry experiment on the synthesis and application of an active ester cross-linking agent. The experiment involves the preparation of decanedioic acid-N-hydroxysuccinimide ester (NHS-DA), identification of its structure, and its application in improving collagen thermal stability. Initially, NHS-DA is synthesized from decanedioic acid, and N-hydroxysuccinimide using 1-(3-dimethylaminopropyl)-3-ethylcarbondiimide hydrochloride as a condensing agent, achieving a yield of approximately 85%. The product’s structure is confirmed through nuclear magnetic resonance and Fourier-transform infrared spectroscopy, indicating the successful synthesis of high-purity NHS-DA. Subsequently, NHS-DA is applied to cross-link collagen sponge, with differential scanning calorimetry demonstrating enhanced thermal stability, thus promoting its application potential. The experiment is characterized by mild conditions, rapid reaction rates, high yields, and the recyclability of waste acetone, incorporating the use of various advanced instruments. It effectively integrates theoretical knowledge with practical application, fostering students' innovative thinking and expanding their scientific perspectives.

Key words: Decanedioic acid, N-hydroxysuccinimide, Collagen modification, Comprehensive applied chemistry experiment