Swelling capacity
The swelling capacity of a polymer is the amount of a liquid that can be absorbed by it. This test can done by two methods:
- Beaker test method
- Tea bag test method
Beaker test method
In this method- A small amount of superabsorbent polymer material is taken and it is placed in the beaker.
- 100 ml of deionized water is poured into the beaker.
- After 20 min the swollen polymer was separated by using filter paper
- By weighing the polymer, one can find the swollen capacity of the SAP material.
Tea bag test method
- In this method, 0.1 g of SAP material is placed into a permeable bag, which is suspended over excess water in a beaker.
- Wait 20 min. and weigh the bag and then calculate the percentage of swelling through the following formula:
- : / %
- : w1= weight of the polymer
- : w2= weight of the polymer Note: Filter paper only for removing water.