CelluloseＧbasedsuperabsorbent materials are mainly prepared byetherificationandcrosslinking,graft copolymerization and composite modification． Among them, the composite modification mainly includes cellulose/polymercomposite and cellulose/inorganic composite． After modification,the water absorption rate of material can
reachseveral hundredto severalthousandtimes．CelluloseＧbased water absorbing materials also have biodegradability,so the application prospectis broad．
Since the 1960s, the super absorbent material is an insoluble hydrophilic polymer with a rapid development speed, presenting a moderately cross-linked three-dimensional network structure. It can absorb hundreds to thousands of times of distilled water, emulsions and physiological fluids, gel-like and good water retention . Super absorbent materials are generally divided into starch series, synthetic resin series and cellulose series , and the most widely used is super absorbent resin (SAPs). , It can absorb thousands of times the weight of water, has excellent water absorption and water retention capacity, and is widely used in disposable sanitary products, industry, agriculture and medicine . ) And carbonic acid (AA). These crosslinking agents are mainly non-renewable petroleum resources, which are biologically incompatible and non-degradable materials, which will cause environmental pollution . Super absorbent material based on World Health Organization cellulose. Compared with environmental protection and sustainable development of resources, the preparation of cellulose-based superabsorbent materials has shifted the focus of research to biodegradable materials.
Study on the preparation and performance of cellulose-based superabsorbent materials Cellulose is one of the most abundant biological resources in the world, with easily degradable physical and chemical properties . It is widely derived from various agricultural products such as cotton, straw, and grass. Among them, the annual output can reach 10 billion tons, which is an environmentally friendly bio-renewable material. Cellulose is a polymer of linear polysaccharide macromolecules composed of glucose as a small unit through βG1, 4G glycosidic bonds. It contains primary hydroxyl groups with higher activity, which is conducive to the formation of intramolecular and intermolecular hydrogen bonds, which is of great significance to the formation of chains. At the same time, the presence of a large number of primary hydroxyl groups is also conducive to the modification and chemical modification of cellulose. Thereby forming derivatives . Natural cellulose itself has certain water absorption properties, but because of the highly dense crystalline structure, most of the hydroxyl groups are in a hydrogen bond association state, which limits its own water absorption capacity. Therefore, people pass A series of chemical reactions connecting hydrophilic hydroxyl groups, carboxyl groups, and amide groups to destroy this crystal structure, and then moderate cross-linking to ensure the gel strength after water absorption.
Post time: Dec-19-2020