Polymers around us Science activity in Kindergarten No. 240 Warsaw, Poland 04.2012
1. Building polymer model• Explain to the children where they use polimers (eg.plastic cups, chairs, toys).• Using paper clips build 3 chains. Explain that plasticis made from chains of polymers.
2. Teflon messages•Cut a piece of Teflon Tape than write a secret message on the tapewith the marker.•Stretch the tape from top to bottom, making your message taller,not longer. Pull carefully so that you don’t tear your message.Suddenly you can’t read your message anymore! Give themessage to a friend and see if they can figure out how to make theletters their original shape again.•Pull on the tape from end to end making the letters short again.When you are done pulling the tape, message will look normalagain.
Explanation:Teflon Tape is a type of polymer calledpolytetrafluoroethylene (PTFE). This is akind of polymer that has long chains ofmolecules lined up side-by-side and on topof each other. If you try to stretch the tapeend to end before stretching it from top tobottom, you won’t be able to stretch it muchat all. That is because the polymers arebonded to each other very tightly. But, thereare lots of chains stacked on top of eachother. These stacks make it possible to pullthe tape from top to bottom and stretch yoursecret message. When the polymer chainsare pulled from top to bottom they slide overone another and reduce the number ofchains in a section without breaking thechains themselves. When the tape is pulledback end to end, the chains are realignedand your message is legible again.
3. „Smelly" balloonsSome materials are more porous than others. Compare how porousdifferent kinds of balloons. Put an drop of extract in ballon (eg. vanillaextract, deodorant etc). Then blow a balloon. Give it to the children. Theydiscover that balloon smell. Although balloons are not engineered to haveparticularly porous membranes, it will be interesting to observe thatparticles travel through the membrane and we are able to smell forexample vanilla odour.
4. Vanishing styrofoam Use a solvent like acetone to show that polystyrene packaging material is mostly air. The acetone easily dissolves the polystyrene, leaving very little residue. Put a styrofoam in acetone. Safety Notes: Experiment should be perform by a teacher. Do not swallow acetone. Use it in ventilated rooms. May cause eye irritation. Wash an eye with water Experiment should be perform by a teacher. Longer exposure to skin may cause skin irritation.
5. Thirsty polymerChildren predict how much distilled water can be poured into 1-2 spoons ofpolyacrylate, the absorbent polymer in disposable diapers.Materials Needed:2 spoons, sodium polyacrylate, 400-mL graduated cylinder or a cup, distilledwater
ProcedureTalk with children about how polymers can bechanged to make them useful for differenttasks. What properties would you want apolymer to have if it was going to be in adiaper? Absorbent, safe, etc. This nextdemonstration and experiment deals with thepolymer used in diapers called sodiumpolyacrylate. We are going to explore theabsorbency of this polymer. Teacher put 2spoons of sodium polyacrylate in measuringcylinder. Then asks how much water it couldabsorb. Then pour water and mix it well.Sodium polyacrylate should absorb morethan 300 ml of water.Safety Notes:Do not swallow sodium polyacrylate.Experiment should be perform by a teacher.
6. Bouncing ballIntroductionThe bouncing ball in this activity is made from a polymer. Polymers aremolecules made up of repeating chemical units. Glue contains the polymerpolyvinyl acetate (PVA), which cross-links to itself when reacted with borax.Materials Needed:borax (found in the laundry section of the store)white (makes a non-transparent ball) or blue or clear school glue (makes atranslucent ball)warm waterfood coloring (optional)ziploc bagpaper towels
Procedure•Pour 2 tablespoons warm water and 1/2teaspoon borax powder into the cuplabeled Borax Solution. Stir the mixtureto dissolve the borax•. Add food coloring, if desired.• Pour 1 tablespoon of glue into the cuplabeled Ball Mixture.•Add 1/2 teaspoon of the borax solutionyou just made Stir carefully.•Take the white substance out of the cupand start molding the ball with your hands.The ball will start out sticky and messy,but will solidify as you knead it.• Plastic ball can be stored in a sealedziploc bag.