Swelling capacity

The swelling capacity of a polymer is determined by the amount of liquid material that can be absorbed by it. This test can done by two methods:

1. Beaker test method
2. Tea bag test method

Beaker test method

In this method

• A small amount of superabsorbent polymer material is taken (0.1g) 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, 0.1g of SAP material is placed into a permeable bag, which is suspended over excess water in a beaker.
• Note the time: 20 min. And weigh the bag and we calculate the percentage of swelling through the following formula:

  (w2-w1)/(w1) %

  w1= weight of the polymer (Before swelling)

  w2= weight of the polymer (After swelling)

• Note: Filter paper only for removing water.

References