Polyacrylamide
Polyacrylamide is an acrylate polymer formed from acrylamide subunits that is readily cross-linked. Acrylamide needs to be handled using Good Laboratory Practices (GLP) to avoid poisoning since it is a neurotoxin. Polyacrylamide is not toxic, but un-polymerized acrylamide can be present near the polymerized acrylamide. Therefore it is recommended to handle it with caution. It is highly water-absorbent, forming a soft gel used in such applications as polyacrylamide gel electrophoresis and in manufacturing soft contact lenses.
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)".
Ionic substances like salt cause Polyacrylamide to release its absorbed substance.
External Links
http://scifun.chem.wisc.edu/CHEMWEEK/polymers/polymers.html