Super absorbent polymer
What Is SAP?
“Extrasorb – Super Absorbent is capable of absorbing water to a level of about 300 times its own weight and its huge water holding and absorbing capacity can be used to retain, block, and absorb liquid and hence turn water to gel. It is capable of absorbing water to a level of about 300 times its own weight and its huge water holding and absorbing capacity can be used to retain, block, and absorb liquid and hence turn water to gel. The ability to absorb depends on the ionic concentration of the aqueous solution and can be as much as 300-500 times the weight of SAP.
Talking in chemical terms, these are the high molecular cross-linked polymers. These cross-linked polymers are the main reason for its highly absorbing nature as these absorb the aqueous solution due to the strong hydrogen bonding with the water molecules. These are made in the presence of an initiator, from the process of polymerization of acrylic acid which is blended with potassium hydroxide or sodium hydroxide to create the respective polyacrylic acid salt.
A diffusion gradient is formed due to the neutralization of the backbone of the polymer by potassium or sodium. Water molecules are attracted to the network because of this diffusion gradient. The cross-linking which exists in the network doesn’t allow the chain to straighten even when it wants to thereby result in the expansion of the particles as the water molecules move through the network.
The water-loving Carboxylic acid group (-CO OH) forms its backbone which makes it hydrophilic. There takes place the interaction of polymer/solvent as and when water is added to the SAP and result in the hydration and formation of hydrogen bonds which is responsible to hold the water tightly.
Functionality of Super absorbent polymer:
Super absorbent polymer has basically 2 functional properties which are due to the two modules of elasticity and swelling as discussed below:
It is a very important module for the swollen superabsorbent polymer. The polymer in the powdered form is blended with fibers such as cellulose and thermoplastic. To ensure that very less number of cross-links are there to link the chains together, the polymers chains must have high molecular mass so that it remains hugely insoluble but at the same time highly expandable too.
Osmotic pressure is responsible for the swelling of the cross-linked and ionized network of the polymer. To increase the absorbing capacity there should be as less cross-linking in the polymer as possible to enable the polymer chain to adopt the configuration which is widely spaced.
The degree and the type of cross-linking done to make the gel determine the absorbing and the swelling capacity of the superabsorbent polymer. The density of cross-linking is inversely proportional to the swelling and absorption as explained below:
- If the SAP’s are cross-linked with low density
then they generally have a tendency to swell to a greater degree and have a more absorbing capacity. It also results in these gels being softer and sticky in nature.Alternatively,
if the SAP has highly dense cross-linked.
it results in a low level of absorbing and swelling capacity.
Sodium polyacrylate, also known for its liquid locking capacity, is a sodium salt of polyacrylic acid with the chemical formula [−CH2−CH(CO2Na)−]n .
Sodium polyacrylate can absorb many times of its own weight in water. It starts out as a powder and when comes into contact with liquid, it absorbs and swells to gel form. It’s not easy to squeeze the liquid out of this gel.
As one of the functional and most useful polymers, Sodium polyacrylate has a very high absorbent power. This is anionic polyelectrolyte that comprises of carboxylic groups (charged negatively). Sodium polyacrylate was in crosslinked form. N,N-methylene-bisacrylamide (bisAM -crosslinking compound) and solution polymerization were used to form this polyacrylate. For surface-crosslinking, ethylene glycol diglycidyl ether (EDGE) was applied, and after that it was transformed by using inorganic salt for deriving superabsorbent absorbency in 0.9 wt% NaCl aqueous solution. The strength of hydrogel is also high with this solution.
The Sodium Polyacrylate is widely used in the hygiene products such as the baby diapers, the sanitary napkins, and the protective underwear for the adults.
SAP has a huge absorbing capacity, maintenance ability, and good permeability thereby making it apt to be used in baby diapers to prevent the infiltration process to happen again at a certain level of pressure.read more
SAP is being used in adult diapers too to help the people who lack a voluntary control over urination. It has a layered construction due to which 0.9 % of the NaCl is transferred to the core structure of the absorbent where it is locked tightly to prevent leaking.read more
A women’s sanitary napkin should have the ability to retain and absorb water so as to keep the napkin dry and make the women feel comfortable. SAP has the required ability to resist moisture, good absorbing capacity, gel strength and fast suction of the blood.read more
SAP used in a cable has swelling abilities to prevent the water from penetrating the communication cable or the underground power cables. swells to a larger extent to block the water penetration by sealing the voids in the cable immediately thereby preventing the movement of water.read more
It is a portable plastic bag like structure filled with refrigerated gel or liquid or water. Water has a high latent heat of fusion and hence it can absorb a lot of heat before it is warmed above 0-degree Celcius. These packs are used to keep the food cold, to insulate the containers while shipping, or as a cooling bag to get relief from the pain inflicted by minor injuries.read more
It replaces the traditional sandbags which were used in flood defense. It is a jute bag which contains SAP inside the inner bag which is finely woven. It is soaked in water for 3 to 5 minutes as a result of which the bag inflates itself to 30 times of its original size. This inflated bag can be used for constructing flood defense and hence controlling flood.read more
The SAP disposable urine bags are very convenient to use. It has a fabric pouch which is non-woven and contains a polymer which is biodegradable and disables the growth of bacteria and enhances the absorption of liquid waste thereby converting it into a gel bag that is spill-proof, odorless, non-toxic and safe to dispose of.read more
SAP helps to cool you down during strenuous activities due to the ability of the evaporative cooling material which is a fabric that absorbs water and then slowly releases it through evaporation. It just needs to be soaked in water for about 1 to 2 minutes, followed by squeezing out the excess water present if any and then enjoying the cooling effect for 5 to 10 hours.read more
203, 6-3-652 D/28, 2nd Floor,
Dhruvatara, Amrutha Estate,
Telangana, India. Pin Code-500082.
Phone: +91 040–40055050, 40202121
Call Now +91 96183 33911
Monday – Saturday 10:00AM – 7:30PM IST
Copyright © 2018. All rights reserved.