Water- absorbent polymers or Hydrogels
Water- absorbent polymers or hydrogels are water-insoluble hydrophilic polymers, able to swell and absorb amounts of water, saline solutions, or physiological fluids as high as 10- 1000 times their own weight. They consist of water, saline solutions, or physiological fluids as high as 10- 1000 times their own weight. They consist of polyelectrolytes or other highly hydrophilic polymeric matrices, usually bearing crosslinking sites along the macromolecular chains in order to avoid dissolution. These polymers generally contain carboxylic groups that are in equilibrium with their dissociated form in the presence of water or carboxylate groups. The polymer coils extend themselves and widen in consequence of the electrostatic repulsion of negative charges. Carboxylate groups are also able to interact through hydrogen bonding with additional quantities of water.
Water absorbent polymer also rere to as sush powdenis a polymer which wll absorb and etin erardinariy massive amounts of a lquid rltive to their own mass Water giping polymers that are casfed as hydrogels once cross- inked, absorb iquid sluions thrugh chemical element bonding with water molecules. An SAPs abitly to soak up water could be an isue of the ionic concentation of the souion. The lrgest use of water absobentis found in personal dsposable hygiene merchandise, like baby dapers, adut potcting undrclothes and santay napkins.