Novel Degradable Superabsorbent Polymers Based on Carboxymethyl Cellulose

In this study, biocompatible and biodegradable superabsorbent polymers (SAPs) were prepared from carboxymethyl cellulose (CMC) using citric acid as a crosslinking agent, utilizing a high-concentration CMC paste and a short annealing process. The effects of CMC molecular weight, annealing temperature and time, and crosslinker concentration on the absorption properties in saline solution were evaluated. In addition, the effects of mixing CMC SAPs with different molecular weights were explored to optimize performance. The results showed that CMC molecular weight significantly affected absorption properties, with medium molecular weight (395 kDa) exhibiting the best overall performance. The content of the crosslinking agent and annealing conditions were also critical—higher crosslinking improved absorption under load but reduced free swell absorption and retention. In addition, the absorption properties could be optimized by appropriately mixing the CMC SAPs with different molecular weights, indicating complementary interactions that enhance performance beyond the individual contributions of each SAPs. These findings can contribute to the development of environmentally friendly, high-performance superabsorbent materials for personal care products as a sustainable alternative to conventional petroleum-derived SAPs.