Polyacrylamide 498674 213899977 2008-05-21T07:32:00Z Alexandrov 411053 [[Image:Polyacrylamide.png|thumb|Polyacrylamide]] '''Polyacrylamide''' ([[IUPAC]] '''poly(2-propenamide)''' or '''poly(1-carbamoylethyelene)''') is a polymer (-CH<sub>2</sub>CHCONH<sub>2</sub>-) formed from [[acrylamide]] subunits that can also be readily cross-linked. Acrylamide needs to be handled using [[Good Laboratory Practice|good laboratory practices]] (GLP) to avoid poisonous exposure since it is a [[neurotoxin]]. Polyacrylamide is not toxic, but unpolymerized acrylamide can be present in the polymerized acrylamide. Therefore it is recommended to handle it with caution. In the cross-linked form, it is highly water-absorbent, forming a soft [[gel]] used in such applications as [[SDS-PAGE|polyacrylamide gel electrophoresis]] and in manufacturing soft [[contact lens]]es. In the straight-chain form, it is also used as a [[thickener]] and [[suspension (chemistry)|suspending]] agent. More recently, it has been used as a subdermal filler for æsthetic facial surgery (see [[Aquamid]]). ==Uses of polyacrylamide== One of the largest uses for polyacrylamide is flocculate or coagulate solids in a liquid. This process applies to [[industrial wastewater treatment|wastewater treatment]], and processes like [[paper mill|paper making]]. Most polyacrylamide is supplied in a liquid form. The liquid is subcategorized as solution and emulsion polymer. Even though these products are often called 'polyacrylamide', many are actually [[copolymer]]s of [[acrylamide]] and one or more other chemical species. The main consequence of this is to give the 'modified' polymer some [[ionic potential|ionic]] character. It has also been advertised as a [[soil conditioner]] called [[Krilium]] by [[Monsanto]] in the 1950s and today "MP", which is stated to be a "unique formulation of PAM (water-soluble polyacrylamide)". The anionic form of polyacrylamide is frequently used as a soil conditioner on farm land and [[construction sites]] for [[erosion control]], in order to protect the [[water quality]] of nearby [[rivers]] and streams.<ref>Wisconsin Department of Transportation. Madison, WI.[http://www.dot.wisconsin.gov/library/research/docs/finalreports/tau-finalreports/polyacryl.pdf "Polyacrylamide as a Soil Stabilizer for Erosion Control."] January 2001. Report No. WI 06-98.</ref> The polymer is also used to make Gro-Beast toys, which expand when placed in water, as the [[Test Tube Aliens]]. The non-ionic form of polyacrylamide has found an important role in the potable [[water industry|water treatment industry]]. Trivalent metal salts like [[ferric chloride]] and [[aluminium chloride]] are bridged by the long polymer chains of polyacrylamide. This results in significant enhancement of the [[flocculation]] rate. This allows [[water purification|water treatment]] plants to greatly improve the removal of total organic content (TOC) from raw water. ==Environmental effects== Some research <ref>Smith, E. A., S. L. Prues, F. W. Oehme.[http://www.mindfully.org/Plastic/Polymers/Polyacrylamides-Degradation1jun97.htm "Environmental Degradation of Polyacrylamides and its Effects of Environmental (Outdoor) Exposure."] ''Ecotoxicology and Environmental Safety 37(1).'' June 1, 1997.</ref> indicates that polyacrylamide can degrade under normal environmental conditions, releasing acrylamide, a known nerve toxin. Some older research at first indicated that Polyacrylamide had the potential to host a nerve toxin, however recent research shows otherwise.<ref>http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VB5-3YXB1NM-D&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=0bc485f58dfc0c83d608bdd91bd019ca</ref> ==See also== * [[Chitosan]] * [[Sodium polyacrylate]], a similar material ==External links== * [http://scifun.chem.wisc.edu/CHEMWEEK/polymers/polymers.html Chemical of the Week: Polymers] - "Science is Fun" site at University of Wisconsin-Madison * [http://science.howstuffworks.com/question581.htm How do polymer crystals work and why do they absorb so much water?] - "How Stuff Works" site * [http://www.gel-electrophoresis.com/gels/articles/polyacrylamide-gels/ Polyacrylamide Gels] ==References== {{reflist}} [[Category:Gels]] [[Category:Neurotoxins]] [[Category:Polyacrylates]] [[Category:Polyelectrolytes]] {{Polymer-stub}} [[de:Polyacrylamid]] [[fr:Polyacrylamide]] [[nl:Polyacrylamide]] [[pl:Poliakrylamid]] [[pt:Poliacrilamida]] [[ru:Полиакриламид]] [[sv:Polyakrylamid]] [[zh:聚丙烯酰胺]]