The sodium polyacrylate is a superabsorbent polymer that comes in the form of a white powder and when it absorbs water it takes on the form and texture of a white water gel. This water-absorbing capacity is the main reason for the uses of sodium polyacrylate that we are going to see below.
SUPERABSORBENT IN BABY NAPPIES, SANITARY NAPKINS, SANITARY NAPKINS
Sodium polyacrylate has one of its main uses in its performance as a super water absorbent in baby nappies and sanitary napkins. Although manufacturing companies are not obliged to disclose each specific material in nappies and sanitary napkins, they all have a similar structure. They consist of 2 liners: 1 outer liner to insulate the nappy or pad from the skin and an inner liner to allow liquid to enter. In the centre there is an absorbent material, a powder consisting of sodium polyacrylate, which is responsible for the absorption of both nappies and sanitary towels.
COLD PACKS (PADS)
Cold compresses that behave like a gel when frozen have sodium polyacrylate in their interior, which allows the compress to have the solidity of a cold compress by retaining the water.
To avoid spillage of liquids during transport of some food products, e.g. meat, cushioned sheets containing sodium polyacrylate are used to absorb liquids. In the case of meat, you can see in the individual trays, the film underneath to absorb any blood that might spill out.
Sodium polyacrylate in addition to trapping water in its ions is able to trap some metals present in water such as magnesium, iron or zinc. This helps certain detergents to work more effectively.
Chelating agents neutralise the presence of heavy metals found in water, dirt and other substances that may be found in laundry, making the detergent purer and more effective at cleaning and neutralising laundry odours.
Another use of sodium polyacrylate would be as a thickening agent both in industrial processes and in cosmetics. As a thickening agent, it improves the viscosity of water-based compounds and increases their stability.
In some electrical installations that have to be in contact with water, the wiring is coated with sodium polyacrylate. In this way, even if the wiring is well insulated, any small leakage will be absorbed by the sodium polyacrylate.
Superabsorbents are increasingly used for water retention to keep the soil moist for a longer period of time. For this purpose, however, it is recommended to use potassium polyacrylate o hydrogel (same product), which are also super water absorbers, but where there is no risk of sodium poisoning the plants. The advantages of using a water absorber to save irrigation time and costs are clear.
Sodium polyacrylate is one of the most commonly used products at science fairs and events. The observation of the water absorption of sodium polyacrylate is a polymer experiment. In addition to this experiment, the polyacrylate, having absorbed water and coming into contact with air, looks like artificial snow. This makes it a curious and fun science experiment. Sodium polyacrylate is often used as a base for powder products to make artificial snow. You can find more information here: sodium polyacrylate based artificial snow.
SODIUM POLYACRYLATE PROPERTIES
You can see the formula and properties of sodium polyacrylate in this section: Properties of sodium polyacrylate