Superabsorbent Polymers in Diapers

Disposable diapers/nappies are taken apart to discover the sodium polyacrylate polymer inside that makes them highly absorbent. By dissecting and testing the polymer, students learn how everyday products use chemistry to solve real-world problems.

1. Begin with a group demonstration: place a diaper in a shallow tray and pour water into it a quarter cup at a time.
2. Continue until the diaper reaches saturation and water no longer absorbs. Cut the diaper open to reveal the gel-like polymer inside.
3. Cut open a diaper along the seams and remove the cotton and polymer crystals into bowls.
4. Add water gradually, spoonful by spoonful, to show how the sodium polyacrylate absorbs water.
5. Optionally perform in paper cup and 'tip' it upside down on top of a person to show that the water has all been absorbed (practice this before attempting).

Diaper Polymer - Cool Science Experiment - SpanglerScienceTV:

📄 DIGGING INTO DIAPERS - Morehead Planetarium & Science Center Afterschool: https://ncsciencefestival.org/sites/default/files/documents/Digging%20into%20Diapers.pdf

• Compare absorbency of different diaper types (overnight, swim diapers, store brands).
• Use food coloring in the water to make absorption more visible.
• Time how quickly different polymers absorb water using a stopwatch.
• Compare diaper polymers with other superabsorbent polymers such as instant snow or water beads.

• Use only clean, unused disposable diapers.
• Supervise students when using scissors.
• Dispose of used diaper parts and polymer safely in trash (do not pour down sink).
• Avoid ingesting polymer or touching eyes after handling.

• What material inside the diaper is responsible for absorbing water? (The superabsorbent polymer sodium polyacrylate.)
• Why is it important to compare equal amounts of polymer when testing absorbency? (To ensure a fair and accurate comparison between brands.)
• How do the cotton fibers in a diaper help the polymer work? (They spread out the polymer and distribute liquid for even absorption.)
• How much water can one teaspoon of sodium polyacrylate absorb? (Up to about 800 times its own weight in water.)
• If you were designing a new diaper, what features would you focus on to make it effective and comfortable? (Absorbency, leak protection, comfort, and cost efficiency.)