Swelling capacity explained

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:

1. Beaker test method^[1]
2. Tea bag test method^[2]

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.^[3]

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:

(w2-w1)/(w1) %

w1= weight of the polymer (Before swelling)

w2= weight of the polymer (After swelling)

• Note: Filter paper only for removing water.

Notes and References

1. Anandan . Dhivyaa . Madhumathi . G. . Nambiraj . N. Arunai . Jaiswal . Amit K. . June 15, 2019 . Gum based 3D composite scaffolds for bone tissue engineering applications . Carbohydrate Polymers . 214 . 62–70 . 10.1016/j.carbpol.2019.03.020 . 30926008 . 88481556 . 0144-8617.
2. Zhong . Peihua . Wang . Jun . Wang . Xiaoxian . Liu . Jiaping . Li . Zhen . Zhou . Yichuan . 2020 . Comparison of Different Approaches for Testing Sorption by a Superabsorbent Polymer to Be Used in Cement-Based Materials . Materials . en . 13 . 21 . 5015 . 10.3390/ma13215015 . free . 1996-1944 . 7664450 . 33172166. 2020Mate...13.5015Z .
3. A beaker method for determination of microplastic concentration by micro-Raman spectroscopy . 10.1016/j.mex.2023.102251 . 2023 . Yang . Zijiang . Arakawa . Hisayuki . MethodsX . 11 . 37448948 . 10336159 .