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Agriculture at Work:

Bio plasticYou might have heard the question: “Paper or plastic?” Why does it matter? What is plastic made from? What works for the environment?

Look at the plastic you use everyday. It can be hard or soft, thick or thin, stiff or flexible, and it comes in many colors. Today, most plastics are made from petroleum, a non-renewable resource. But could plastics be made from renewable resources?

Do • • • •1. Gather these materials: 1 tsp glycerin, 1 Tbs corn

starch, 1 tsp vinegar, 4 Tbs water, aluminum foil, cooking spoon, cooking pot. You will need a stove or hot plate.

2. Put 1 tablespoon of cornstarch into the cooking pot. 3. Add 4 tablespoons of water. 4. Add 1 teaspoon of vinegar.5. Add 1 teaspoon of glycerin. 6. Mix and turn the heat on medium. Stir continuously. The

mixture will turn from liquid, white mixture to clear, gel-like consistency. When it bubbles, it is done! Remove from heat.

7. Pour the gel onto the aluminum foil. Spread as thin or thick as you like. Depending on the humidity, it might take up to 24 hours to cool completely.

What can you do with your plastic?

Caution: Check with an adult before using the stove or a hot plate.

What’s the science? Large cellulose molecules, like starch, are long chain

polymers. In this experiment, two ingredients change the properties of the polymer plastic. By adding a small amount of vinegar, you break up some of the polymers chains, making the plastic less brittle. The glycerin acts as a plasticizer which “lubricates” the plastic. If you want the plastic more pliable, add more glycerin. If you want the plastic to be stiff, add less glycerin.

Minimum Completion Time45 minutes

Skill LevelIntermediate Age 11-13

Learner Outcomes• Recognizes properties

of crops make sustainable industrial products

• Tests different properties of plastic

Science Skills • Build/construct• Compare/contrast• Observe• Predict

Life Skills • Think creatively• Reason

Educational Standards• Properties and changes

of properties in matter• Science and

technology in society• Science as a human

endeavor

Success Indicator • Tests materials• Describes the starch to

plastic process

• Corn to pastics

• How plastic bags are manufactured

• Bioplastics from switchgrass

• Turning plants into building blocks

• How plastic bags are made • How stuff works: corn plastic • Students make bioplastic

shoes

• New potatoes for food and feedstock

• Starch-Based Biomaterials Alliance

Records Complete the Observation Log

Acknowledgements: Robert L. Horton, PhD, Ohio State University Extension, Carol Warkentien and Jeanne Gogolski, EP&P LLC

Content adapted from DuPont (www2.dupont.com) and Pioneer (www.pioneer.com) web pages.

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Watch this experiment online.

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Share • • • What happened when you made your plastic?

Reflect • • • What could you do with this plastic?

Generalize • • • How could edible corn plastic help to solve problems in landfills?

Apply • • • What future uses or products can you imagine for plastic made out of corn?

Name ————————————————

Date ————————————————

Records—Intermediate LevelAgriculture at Work: Bio plastic

The 4-H Name and Emblem is protected under 18 USC 707.Support for this resource was provided by:

No endorsement of a commercial entity or its products or services is intended or implied.

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The plastic you use everyday is probably made from a petroleum product. About 95% of all the plastic today started out as crude oil. Over 6000 products are made from petroleum: trash bags, sunglasses, milk bottles, the coatings on medicine, and much more.

Plastic

What is plastic? Plastic is made from long chains of carbon molecules we call polymers. Different combinations and different polymers make different kinds of plastics.

Can polymer chains come from a renewable resource? Plastics made from plant sources are called bioplastics. It all starts with photosynthesis. Plants form sugars from carbon dioxide using the energy of sunlight. Large cellulose molecules, like starch, are long chain polymers. These polymers are different than the polymers from petroleum, but if they are mixed with the right chemicals and “cooked” precisely they become plastics.

Background Information

What plants can be used?Corn is the most common plant used, but it isn’t the only one. Many plants like potatoes, soybeans and wheat create enough starch that plastics can be made from them. Potatoes have been developed, for example, producing starch ideally suited to industrial processing. Genetic modification of poplar trees is being used to reduce the pollution created when making wood pulp into paper. Scientists are using biotechnology to see if the structure of plant carbohydrates can be modified to make plastics.

More Challenges

• Create different recipes and compare flexibility, color and strength.

• Research the amount of petroleum used in plastics. Which ones could be replaced with bioplastics?

• Test biodegradibilty of a sample of corn plastic and a sample of petroleum plastic by creating an experiment and gathering data over time.

Glossarypolymer—a chain of large, single molecules (monomers) linked together.

biodegradable—the capacity of a material to decompose naturally over time, to be broken down by microorganisms.

bioplastic—form of plastic made from renewable plant source rather than non-renewable petrolum.

E-Bite • • • • • Coca-Cola’s efforts at sustainable packaging

The 4-H Name and Emblem is protected under 18 USC 707.Support for this resource was provided by:

No endorsement of a commercial entity or its products or services is intended or implied.

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• • • • • Making PlasticDescribe your plastic. Here are some words you can use:

bioplastic

flexible

brittle

transparent

opaque

smooth

rough

thin

thick

Design and try some experiments. How can you test your plastic for ....

Flexibility?

Hardness?

Biodegradability?

Name ————————————————

Date ————————————————

Records—Intermediate LevelAgriculture at Work: Bio plastic

Agriculture at Work: Bio plastic

ObservationLog