Goal: Scouts will understand the difference between natural and synthetic plastic. Scouts will understand the structure of polymers.
Supplies: balloons*, skewers (thin), hand lotion, cooked and uncooked spaghetti (or use paper clip polymer model). (*These items are in the Color Your World with Polymer Science kit found at the scout store.)
Human Polymer chain model: Each scout represents a monomer. Hold hands to form a single straight polymer. Have the girls move around the room as a polymer. Now create two parallel polymer lines. Crosslink the polymer by asking 2-3 girls to connect the two lines by holding hands (think of an “H” formation). Have the girls move around the room again. Is it easier to move around the room as a single polymer or as a crosslinked polymer?
Paper Chain Polymer model: Each paper chain is a monomer. Connect them in a single chain to make a polymer. Move the polymer chain around and notice how easily it moves. Crosslink the polymer by taking two single lines and attaching one or two links between the lines (think of an “H” formation). Move it around. Notice how it is more difficult to move the crosslinked polymer.
Manipulate Polymers: For the balloon activity follow the directions in the video. Before inserting the skewer into the balloon, slide it into the hand lotion bottle to make the skewer slippery. When inserting the skewer into the balloon start at the knotted end (but not in the knot) and insert into the darkest area where the polymers are denser. Bring the skewer out the opposite end again where it is the darkest therefore densest area. Move slowly and twist the skewer into the balloon.
The smaller molecules that come together to form polymers are called monomers—small units that link together to form a large polymer. Think of monomers like paper clips that link together to form a chain, and that chain is a polymer. Polymers are made of many monomers linked together. Another model to consider: one Lego brick is a monomer and the structures you build with the Lego bricks are polymers.
Plastics and Common Uses
|#1 Polyethylene Terephthalate (PETE)||Soft drink and water bottles, cleaner bottles, peanut butter containers|
|#2 High-Density Polyethylene (HDPE)||Milk Jugs, shampoo bottles, laundry detergent bottles, some plastic bags|
|#3 Polyvinyl chloride (PVC)||Cling wrap for food, window cleaner bottles, medical vinyl tubing, shower curtains, flooring, and home siding|
|#4 Low-Density Polyethylene (LDPE)||Most plastic wraps, bread bags, frozen food bags, single-use grocery bags|
|#5 Polypropylene (PP)||Yogurt containers, syrup bottles, outdoor carpet, disposable diapers, deli containers|
|#6 Polystyrene (PS)||Disposable plates, disposable cups, meat trays, egg cartons, carry-out containers, straws, building insulation|
Find more information at Smart Plastics Guide1
Outcome: Students will understand plastics are polymers and that polymers are different based on the configuration of the molecules.
1Sea Studios Foundation. (n.d.). Smart Plastics Guide - PBS. Smart Plastics Guide. Retrieved September 7, 2022, from https://www-tc.pbs.org/strangedays/pdf/StrangeDaysSmartPlasticsGuide.pdf