Superabsorbent materials

Superabsorbent materials are frequently used in disposable absorbent articles to help improve the absorbent properties of such articles. Superabsorbent materials are generally polymer-based and are available in many forms, such as powders, granules, microparticles, films and fibers. Upon contact with fluids, superabsorbent materials swell by absorbing fluid into their structure. The superabsorbent materials quickly absorb fluids insulted into the articles and retain such fluids to prevent leakage and provide a dry feel even after fluid insult (3). 

Certain biodegradable superabsorbent materials, such as those composed of crosslinked polysaccharides, tend to exhibit lower absorbency properties, particularly absorbency under load and gel bed permeability, in comparison to the conventional non biodegradable polyacrylate superabsorbents. 

An absorbent composition is made from a biodegradable absorbent polymer and a surface modifying agent. The superab- 

The cationic polymer is selected from salts of poly(vinyl amine) or copolymers from 2-(acryloyloxy)ethyl-trimethylammonium chloride and 3-(trimethoxysilyl)propyl methacrylate (3). 

Ahmed and A.W. Emiru, Breathable biodegradable hot melt composition, US Patent 7910645, assigned to H.B. Fuller Company (St. Paul, MN), March 22, 2011. 

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Recently, the oxidative formation of the Ce group in carbohydrates has became a strong focus of investigation, since when it is applied to the starch molecule, superabsorbing material based on renewable resources can be produced. Therefore, the development of new catalytic methods for the selective oxidation of terminal alcohols Cg by applying simple and cheap oxidants such as hydrogen peroxide still remains challenging. 

Starch from surplus corn has been converted into a superabsorbent material known as SUPER SLURPER. This is being marketed under license by several companies for use in removing water from refined petroleum products and as an absorbent in bandages and diapers. Biodegradable plastic films of starch mixed with other polymers find application as mulches in agriculture and as a... 

These amino acid anhydrides are usuaiiy made with phosgene. The use of dimethyi carbonate shouid be tested in the preparation of the monomers. Poiyaspartic acid can be made by heating aspartic acid without soivent to form a polysuccinimide which is then hydrolyzed (12.34).186 It can also be made directly from maleic anhydride and ammonia. It promises to be useful as a scale inhibitor in water, an antiredeposition agent in detergents, and such. Gamma-irradiation converts it to a biodegradable superabsorbent material that takes up 3400 g water per gram of dry polymer.187 (Most superabsorbent polymers are based on acrylamide, a neurotoxin.)... 

Clay and mineral fillers have been used for reducing production costs and improving the comprehensive water absorbing properties of superabsorbent materials For example, a poly(acrylic acid)/mica superabsorbent has been synthesized with water absorbency higher than 1100 g H20/g In a typical method of preparation, acrybc acid monomer is neutralized at ambient temperature with an amount of aqueous sodium hydroxide solution to achieve 65% neutralization (optimum) Dry ultrafine (<0.2 tm) mica powder (10 wt%) is added, followed by cross-linker N,N-methylene-bisacrylamide (0.10 wt%) and radical initiator, potassium persulfate The mixture is heated to 60-70°C in a water bath for 4 h. The product is washed, dried under vacuum at 50°C, and screened. 

This paper showed a new method in utilizing textile cellulose wastes such as cotton linter, cotton yarn waste and flax yarn waste, in the production of superabsorbent material. The introduction ofthem into superabsorbentcouldsignificantly reduce theproduction... 

Title Superabsorbent Materials and Uses Thereof Country Patent No. 

Thus, polyelectrolyte gels are highly valuable superabsorbent materials that can be and are employed in various fields. The area of their application will significantly expand when robust composites of the superabsorbent gels with nonwoven materials, mbbets, and so on, will be created. " ... 

Superabsorbent materials (particulates, pulps, and fibres) are frequently incorporated into nonwoven structures for better liquid absorption and retention properties. In addition to the methods for the evaluation of the quality and stmctoral parameters... 

However, when superabsorbent powders incorporated with other nonwoven materials, the blend materials have special porous structure in wet and swelling properties under pressure. The capacity of superabsorbent materials to hold absorbed water inside the network under certain external stress on the material were defined as absorbency under load, " " which simulate the performance of superabsorbent materials in various applications, such as baby diapers and sanitary napkins. 

Dutkiewicz established a model to characterise the change in the void volume in the absorbent stmeture containing superabsorbent materials and also proposed a new testing method to measure the new defined fluid acquisition and storage efficiency, m which water absorbency is measured when a certain weight is placed uniformly on the surface of the swollen gel for a period of time, and the rate of fluid acquisition is measured under load of 2.8 kPa, three insults of 0.9% saline in 75 ml each. The water absorption capacity measurement under near-vacuum suction by using a Buchner funnel (equivalent to a pressure of 22.1 kPa) was also designed. " ... 

Acrylic/methacrylic acid hydrogels exhibit extremely high swelling capacities, e.g., poly (acrylic acid) hydrogels can have water content as high as 99%, and hence are used as a superabsorbing material. The commercially important superabsorbent polymers are cross-linked polymers of partially neutralized acrylic acid or terpolymers of acrylic acid, sodium acrylate, and a cross-linker, or graft terpolymers with starch or poly(vinyl alcohol)... 

The largest use of SAPs, however, is in disposable personal hygiene products. These products include, in the order of volume of superabsorbent materials used, diapers, training pants, adult incontinence products and feminine hygiene products. 

Superabsorbent material was also reported to play a role as a matrix material or binder. Superabsorbent particles can occlude odor control additives, such as zeolites (15). 

White mineral oil (22) Drytech 2035 Superabsorbent material (22) Ethenier -F-UHV Lignocellulosic pulp (17) Favor 953... 

Superabsorbent material, paper diapers, feminine products, oil-water separation materials Drying agents, antifiost agents Drug substrates, horticultural water holding agents, air fresheners... 

Highly branched or cross-linked polymer materials can be obtained through copolymerization of vinyl/divinyl monomers. Such products have applications as ion-exchange resins, chromatographic packings, superabsorbent materials, contact lenses, photoresists, and dmg deliveries. Widely used divinyl monomers are divinylbenzene and ethylene glycol dimethaaylate. 

The functional layers vary greatly for different products because of the variations in their intended uses. For the majority of wounds, the main issues in wound management are to contain exudate, control microbial growth, and combat odor. In these cases, a layer of superabsorbent material, antimicrobial substance, and activated carbon fabric respectively can be laminated into the wound dressing to provide the functional layer. 

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