Supersorbents 8/29/2008

Supersorbents

8/29/2008

Hit Counter

“Superabsorbent polymers (SAP) (also called slush powder) are polymers that can absorb and retain extremely large amounts of a liquid relative to its own mass.”
Wikipedia: http://en.wikipedia.org/wiki/Superabsorbent_polymer (11/3/2008)

Notes

Review Articles

US Patents

Journal Articles

Back to Sorbents

Back to Applications

Back to Plastipedia

Back to Alphabetical Index

Concrete Forms

Warning: Sometimes the older links no longer work. Go to the US Patent Patent number search page, copy the Patent number into the search box and search. For the articles, use your browser to go the Journal site.

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Notes

“Water absorbing polymers, classified as hydrogels, absorb aqueous solutions through hydrogen bonding with the water molecule. So an SAP's ability to absorb water is a factor of the ionic concentration of an aqueous solution. In deionized and distilled water, SAP may absorb 500 times its weight (from 30-60 times its own volume), but when put into a 0.9% saline solution, the absorbency drops to maybe 50 times its weight. The presence of valent cations in the solution will impede the polymers ability to bond with the water molecule.”
Wikipedia: http://en.wikipedia.org/wiki/Superabsorbent_polymer (11/3/2008)

“Superabsorbent polymers are now commonly made from the polymerization of acrylic acid blended with sodium hydroxide in the presence of an intiator to form a poly-acrylic acid, sodium salt(sometimes referred to as cross-linked sodium polyacrylate). This polymer is the most common type of SAP made in the world today. Other materials are also used to make a superabsorbent polymer, such as polyacrylamide copolymer, ethylene maleic anhydride copolymer, cross-linked carboxy-methyl-cellulose, polyvinyl alcohol copolymers, cross-linked polyethylene oxide, and starch grafted copolymer of polyacrylonitrile to name a few. The latter is one of the oldest SAP forms created.”
Wikipedia: http://en.wikipedia.org/wiki/Superabsorbent_polymer (11/3/2008)

Most of the supersorbents for absorbing large amounts of liquid in a short time are lightly crosslinked synthetic polymers. They include acrylic acid or acrylamides which are not biorenewable or biodegradable. They also have little strength in the swollen gel state. Mertens and Holler developed supersorbents based on biodegradable, surface crosslinked polycarboxypolysaccharides having excellent age-stable absorption, even under loads with high attrition resistance. These resins include carboxymethylguar, carboxylated hydroxyethyl or hydroxypropylcellulose, carboxymethylcellulose, carboxymethylstarch, oxidized starch, carboxylated phosphatestarch and xanthan. The supersorbent polymers may, also, be modified by adding carboxyl-free polysaccharides. These supersorbent polymers are swollen, dried and surface crosslinked with covalent and ionic crosslinking agents such as citric acid, butanetetracarboxylic acid polyacrylic acid and divalent metal salts. (RDC 8/29/2008)
Mertens and Holler, US Patent 7,407,912 (8/5/2008) [8/29/2008]

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Review Articles

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

US Patents

12/2/2008

7,459,501
Superabsorbent polymers in agricultural applications

11/11/2008

7,449,219
Superabsorbent polymers having radiation activatable surface cross-linkers and method of making them

10/21/2008

7,438,951
Aqueous super absorbent polymer and methods of use

9/30/2008

7,429,632
Method of manufacturing superabsorbent polymers