Hydrogels have a broad range of applications, but their inherent mechanical weakness limits their practical use. Furthermore, conventional chemical hydrogel cross‐linkers are often toxic and nonbiodegradable. This research is aimed at developing a simple method for creating mechanically robust, biodegradable hydrogels using chemically cross‐linked nano‐starch as a crosslinking agent. We employ a uniform dispersion of nanoparticles for the synthesis of hydrogels using different amounts of vinyl modified nano‐starch cross‐linker (MNSC). Mechanically strong hydrogel is prepared by free radical polymerization of N‐isopropylacrylamide (NIPA) monomer in the presence of MNSC as a cross‐linking agent and potassium persulfate (KPS) as a redox initiator. First, nano‐starch particles (NSPs) are synthesized from micro‐starch granules via acid hydrolysis. The synthesized NSP is then converted to carboxylated nano‐starch particle (CNS) using 2,2,4,4‐tetramethyl‐1‐oxyalpiperidine (TEMPO) mediated selective oxidation of NSP. MNSC cross‐linker is synthesized by the coupling reaction between CNS and 2‐Aminoethyl methacrylate hydrochloride (2‐AEM) in the presence of the coupling agent N‐(3‐dimethylaminopropyl)‐N‐ethylcarbodiimide hydrochloride (EDC). In another approach, a biofriendly cross‐linker has been developed by modifying NSP with the silane coupler 3‐methacryloxypropyl‐trimethoxysilane (MPTS) to fabricate a mechanically strong nanocomposite hydrogel. Synthesized MNSCs can act as cross‐linkers during free‐radical polymerization. The NIPA‐MNSC hydrogels can be prepared only with a small amount of MNSC to overcome the inherent poor mechanical properties of traditionally cross‐linked polymeric hydrogels. The surface morphologies of NSP and MNSCs are observed by field emission scanning electron microscopy (FE‐SEM) images. The superior mechanical properties of the hydrogels are determined using a universal testing machine (UTM).
Majumder et al. (2026) studied this question.