Polymers Demonstrations

See also: Materials

Polymers are large molecules made up of repeating smaller units called monomers. This category explores how polymers form, the different types that exist, and the roles they play in natural and synthetic materials. Understanding polymers helps explain the properties of plastics, fibres, and many substances that are part of everyday life.

Demonstration	Materials	Difficulty	Safety	Summary
Needle Through A Balloon	★☆☆	★☆☆	★☆☆	A balloon can be pierced with a needle without popping if the balloon is reinforced with clear tape. This works because the tape holds the stretched polymer molecules together, preventing the balloon from bursting.
Instant Snow Polymer	★★★	★☆☆	★★☆	A small amount of instant snow polymer rapidly absorbs water and swells to many times its original volume, creating fluffy “snow and causing a temperature change.
Making Casein Plastic	★☆☆	★☆☆	★☆☆	Heating milk and mixing it with vinegar causes the protein casein to separate and form curds. These curds can be dried and kneaded into a moldable bioplastic that hardens over time, demonstrating polymer formation.
Nylon Rope Trick	★★★	★★☆	★★★	The Nylon Rope Trick demonstrates interfacial polymerization, where nylon is formed at the boundary between two immiscible solutions: aqueous 1,6-diaminohexane and adipoyl chloride dissolved in cyclohexane. A continuous strand of nylon can be pulled from the liquid interface, creating a dramatic visual display of polymer formation.
Making Slime	★☆☆	★☆☆	★☆☆	This activity demonstrates polymer chemistry by making slime from glue, baking soda, and contact lens solution. Crosslinking between polymer chains in glue changes the liquid into a stretchy, rubbery material with unique properties.
Bubbling Slime	★★☆	★☆☆	★☆☆	This experiment combines vinegar, xanthan gum, and baking soda to make bubbling slime. The vinegar and baking soda undergo an endothermic chemical reaction, releasing carbon dioxide gas that bubbles through the gooey slime.
‘Dissolving’ Styrofoam in Acetone	★★☆	★★☆	★★☆	When expanded polystyrene foam is placed in acetone (propanone), it appears to dissolve, dramatically shrinking in volume. This striking demonstration shows how acetone breaks down the foam structure by dissolving the polystyrene polymer, leaving only a small residue of solid polymer behind.
Pencils Through a Bag	★☆☆	★☆☆	★☆☆	When pencils are pushed through a water-filled plastic bag, no water leaks out.
Allotropes of Sulfur	★★☆	★★☆	★★☆	When powdered sulfur is heated, it undergoes a series of changes in appearance and physical properties. Sulfur melts, becomes highly viscous as polymer chains form, then flows more freely at higher temperatures before eventually igniting. Quenching burning liquid sulfur in water produces a flexible, rubbery form of sulfur.

Materials
★☆☆ Easy to get from supermarket or hardware store
★★☆ Available in most school laboratories or specialist stores
★★★ Requires materials not commonly found in school laboratories

Difficulty
★☆☆ Can be easily done by most teenagers
★★☆ Available in most school laboratories or specialist stores
★★★ Requires a more experienced teacher

Safety
★☆☆ Minimal safety procedures required
★★☆ Some safety precautions required to perform safely
★★★ Only to be attempted with adequate safety procedures and trained staff