Abstract:

Hydrogel, as a kind of polymer material with broad application prospects, is a hot field of scientific research at present. Synthesis of hydrogel is relatively simple, and it combines organic synthesis chemistry, polymer chemistry, inorganic coordination chemistry and analytical chemistry, showing the potential to be adapted to laboratory teaching. Hydrogel is environmentally friendly and fits the theme of green chemistry, which facilitates the introduction of relevant content in the design of laboratory teaching projects. Although green chemistry education plays an increasingly important role in the cultivation of chemical professionals, it has encountered some obstacles in the practical promotion, such as quantitative descriptions, ambiguous concepts and difficulty in stimulating students' interest. Meanwhile, present quantitative calculation of green chemistry only focuses on the mass change before and after reaction. In response to the teaching dilemma of green chemistry as well as translation of advanced scientific achievements, the latest semi-quantitative evaluation method of green chemistry have also been, together with synthesis of hydrogel, introduced to guide students to find the hydrogels synthesis route with high green degree at the stage of experimental preparation. Finally, sodium carboxymethyl cellulose was extracted and modified from waste cotton, and its degree of substitution was determined by titration. Then, metal ion crosslinking method was used to prepare the colored hydrogel product, and its adsorption performance was tested.

Key words: Semi-quantitative green evaluation method, Waste cotton, Sodium carboxymethyl cellulose, Metal ion crosslinking, Hydrogels