Why it is in news?
- A team at IIT Madras develops a biodegradable, super-absorbent polymer.
What it made of? and problems associated with it.
- Diapers contain super-absorbing polymers, or SAPs, which can absorb and retain a large quantity of liquid.
- They are made of synthetic materials that are non-biodegradable.
- Safe disposal of used diapers is thus becoming a major environmental problem.
Solution by scientists
- scientists from the Department of Chemistry at the Indian Institute of Technology, Madras have developed a biodegradable super-absorbent polymer using chitosan (a kind of sugar extracted from seafood waste), citric acid and urea.
- This super-absorbent has capacity ”” it can absorb 1,250g of water for each gram of the polymer.
A comparison
- The researchers used chitosan obtained from seafood waste source, and two easily available sustainable chemicals ”” citric acid and urea.
- Water absorbing material from a commercial baby diaper was used for comparison.
- The materials (chitosan, citric acid and urea) were mixed in a weight ratio of 1:2:2.
- The mixture was heated in aqueous medium to 100º C in a closed container to form a highly viscous and porous, cross-linked gel denoted as CHCAUR (from chitosan, citric acid and urea).
- The gel was then dried to remove residual solvent and powdered for further study.
- It was found that the water absorption capacity of CHCAUR was about eight times more when compared to super absorbing polymers used in commercial diapers.
Other applications
- It can also find applications in agriculture, especially as a controlled releasing agent of micro- and macro-nutrients to soil.
- The study also mentions that when applied to soil, CHCAUR was found to decrease water evaporation rate significantly.
- The research team is now working on similar biodegradable polymers as a substitute for polyurethane and polystyrene packaging materials that do not degrade.
Source
The Hindu