Compositional Optimization of Carboxymethyl Cellulose-Based Adhesive Hydrogels for Simultaneous Toughness Enhancement...

Hydrogels are highly hydrated cross-linked polymer networks whose composition and structure can be engineered to achieve desirable mechanical properties, adhesion, and biocompatibility for biomedical, functional material, and environmental applications. In this study, acrylamide (AAM) was employed as the primary backbone monomer to construct the fundamental polymer network. Methacrylated lysine (LysMA), methacrylated poly(vinyl alcohol) (PVAMA), and carboxymethyl cellulose (CMC) were incorporated as functional comonomers, while N,N'-methylenebis(acrylamide) (MBAA) served as the chemical cross-linker to establish a stable and tunable three-dimensional structure. The multiple intermolecular interactions of the amine and carboxyl groups provided by LysMA effectively enhanced interfacial adhesion. Meanwhile, PVAMA and CMC synergistically reinforced the network toughness and maintained overall mechanical integrity through hydrogen bonding and chain entanglement effects. After optimizing the compositional ratios, the hydrogel exhibited significantly enhanced mechanical performance, with the tensile stress increasing by approximately 680.2% and the toughness improving by 393.5% compared to the control group without PVAMA, indicating a markedly improved ability to withstand deformation and effectively absorb and dissipate mechanical energy. In terms of adhesion performance, the optimized hydrogel achieved a maximum adhesion strength of 213.63 kPa on aluminum substrates, which is markedly superior to most previously reported systems. Notably, the optimized formulation not only balanced high adhesion strength and enhanced mechanical performance, but also exhibited good fatigue resistance and biocompatibility, confirming its stability and safety under long-term application scenarios. These findings highlight a rational molecular design and compositional optimization strategy for developing high-performance functional hydrogels with broad cross-disciplinary application potential.