Question

How is the water drawn into the polymer?
How is the polymer held in the polymer? What are the intermolecular bonds between the polymer and the water? A diagram again may help.
What factors affect the effectiveness of SAP?

Answer 1

Polymers can be synthesized containing highly electronegative components such as amide linkages. These structures can interact with water by forming physical 'hydrogen bonds'. The H-Bond is an electrostatic interaction between a highly electronegative element and hydrogen such that the hydrogen (say in water) is also covalently bonded to a highly electronegative element, oxygen. => -CONH- => Amide link ... The electronegative carbonyl oxygen will attract the electopositive hydrogen of water forming the H-Bond. High molecular weight structures in water are very 'hydroscopic' polymeric systems that absorb large quanties of water at the polymer surface and at a moderate distance from the polymeric surface. This in turn accounts for the high viscosity (thickness) of such systems in water. Small amounts result in a significant increase in viscosity. Some liquid soaps contain small quantities of Hydroxyethyl Cellulose as a thickening agent along with detergent and antibacterial agents for disinfecting.