Enamine Approach for Versatile and Reversible Functionalization on Cellulose Related Porous Sponges

Abstract

A readily modifiable cellulose sponge was prepared from cellulose acetoacetate (CAA). Facile postsynthetic modification with primary amino-containing modifiers such as octadecyl amine (ODA), cysteine (CYS), and l-glutamic acid (GLU) could be achieved demonstrating the ease of anchoring a broad selection of functional groups to the surface of the sponges. This postsynthetic modification process was systematically characterized by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy, which confirmed the formation of the enamine bonds. Besides, the microstructures and mechanical properties of the sponges were well preserved throughout the postsynthetic modification process. The enamine bonds, as one of the dynamic covalent bonds, were easily formed under mild and neutral conditions and broken under exposure to a low pH stimulus. The enamine bonds were used to modify the CAA sponges, which can achieve the versatility and recycling of cellulose porous materials. Therefore, the resulting...