Super absorbent polymer has a unique three-dimensional network structure, and contains a large number of carboxyl, hydroxyl and other hydrophilic groups, and the moisture absorption ratio can reach hundreds or even thousands of times. At the same time, it has strong water retention capacity. At present, it has been widely used in the fields of health products, agriculture, medical treatment and environmental protection. It is a research hotspot in polymer material industry in recent years. This paper briefly introduces SAP powder prepared from chitosan.
Solution polymerization has the advantages of low viscosity, simple operation and high production efficiency. It is the main synthesis method at present. Freeze induced phase separation and microwave irradiation assisted synthesis are still in the laboratory stage. Inverse suspension polymerization is suitable for the production of granular products, but it can only be produced intermittently. The preparation of super absorbent polymer by organic-inorganic composite method not only solves the defects of traditional resin such as poor salt resistance and slow water absorption rate, but also reduces the product cost, which is an important development direction.
Super absorbent polymer made from natural product chitosan not only has excellent water absorption and water retention capacity, but also the raw materials can be regenerated, non-toxic, excellent biodegradability, and also has the advantages of antibacterial and pH sensitivity. It has a wide application prospect in medical and health care and drug delivery. However, its application in agriculture and other fields is limited because of its high price.
With the deepening of research and the refinement of market demand, the following issues will become the focus of future research: ①Basic theoretical research on the synthesis, response mechanism, swelling kinetics and thermodynamics of intelligent environment responsive water absorbent resin; ②Study on the synthesis and structure-activity relationship mechanism of organic-inorganic composite super absorbent polymer with high efficiency and low cost; ③The synthesis and properties of water absorbent resin with good biocompatibility and high degradability, and the preparation and structure-activity relationship of salt resistant water absorbent resin.
In recent years, the research on super absorbent polymer has become more and more sophisticated, and environmental responsive, low toxicity, degradable and so on have become a research hotspot. Understanding the relevant knowledge of chitosan based SAP powder is conducive to the better application of this kind of polymer materials.