How to Make Bioplastic Ornaments

Bring sustainability into your holiday season with this fun and educational project! Learn how to make bioplastic ornaments, a hands-on way to learn about materials, science, and the environment while creating unique decorations for the tree.

What Are Bioplastics?

Bioplastics are materials made from natural, renewable resources like cornstarch. They’re a great alternative to traditional plastics because they’re biodegradable, meaning they break down naturally in the environment. Unlike petroleum-based plastics, bioplastics are made from plants and are safer for the planet. Learn more about natural and man-made materials.

In this project, kids will create bioplastics while learning about how materials work, why bioplastics are sustainable, and how we can use science to solve real-world problems.

💡Explore more Christmas science ornaments [here].

Materials:

• 2 tablespoons cornstarch
• 1 tablespoon vinegar
• 1 teaspoon glycerin (available online or at drugstores)
• 4 tablespoons water
• Food coloring (optional)
• Holiday-themed cookie cutters (stars, trees, snowflakes, etc.)
• Mixing bowl and spoon
• Small saucepan and stovetop or hot plate
• Parchment paper or silicone mat
• Rolling pin
• Toothpick (for making hanging holes)
• Ribbon or string for hanging

How to Make Bioplastic Ornaments

1. Mix the Ingredients

Combine cornstarch, vinegar, glycerin, and water in a mixing bowl. If you want your ornaments to be colorful, add a few drops of food coloring.

2. Cook the Mixture

Pour the mixture into a small saucepan and heat on low to medium. Stir constantly for 90 seconds to 2 minutes as the mixture thickens into a dough-like consistency. Make sure to keep stirring so it doesn’t burn!

3. Shape the Dough

Let the dough cool for 1-2 minutes. Place it on parchment paper or a silicone mat, and roll it out to about 1/8 to 1/4 inch thick using a rolling pin.

Approximate Yield:

• Small Cookie Cutters (2-3 inches): Around 6-8 ornaments.
• Medium Cookie Cutters (3-4 inches): Around 4-6 ornaments.
• Large Cookie Cutters (4-5 inches): Around 3-4 ornaments.

4. Cut Out Shapes

Use cookie cutters to create fun holiday shapes. Gently transfer each shape to a clean sheet of parchment paper.

5. Add Hanging Holes

Use a toothpick to poke a small hole near the top of each shape so you can add a ribbon for hanging later.

6. Let the Ornaments Dry

Let the ornaments dry for 1-2 days at room temperature, flipping them occasionally for even drying.

7. Decorate (Optional)

Once dry, you can paint or decorate your ornaments with glitter, markers, or other fun materials.

8. Add a Ribbon

Thread a piece of ribbon or string through the hole to create a loop for hanging.

Can you double the batch?

My suggestion is to work in small batches for the best results! It’s better to work in single batches because the bioplastic mixture thickens quickly as it heats, making it easier to manage and maintain the right consistency. Larger batches can be harder to stir evenly, increasing the risk of clumping or burning.

Science Behind How to Make Bioplastic Ornaments

What Makes Bioplastics Work?
When you heat cornstarch and water, the starch breaks into long chains that connect with water molecules through hydrogen bonds. These bonds make the bioplastic thick and stretchy.

Why Add Glycerin?
Glycerin makes the bioplastic flexible so it doesn’t crack when you roll or shape it. It’s like a softener that keeps the material easy to work with.

What Does Vinegar Do?
Vinegar helps the ingredients mix smoothly and speeds up the reaction that makes the bioplastic form.

How Do Bioplastics Harden?
As the bioplastic cools and dries, water evaporates, strengthening the bonds between starch chains. This is why the ornaments harden at room temperature.

Why Are Bioplastics Better for the Planet?
Bioplastics are made from plants, not oil, and break down naturally over time. This makes them a great choice for reducing waste and pollution!

Why This Activity Is Perfect for STEAM Learning

• Science: Learn how hydrogen bonds create bioplastics and explore the properties of materials.
• Technology: Understand how renewable materials like cornstarch can replace petroleum-based plastics.
• Engineering: Experiment with rolling, cutting, and shaping the dough.
• Art: Personalize your ornaments with shapes, colors, and designs.
• Math: Practice measuring ingredients and comparing drying times.

Bioplastics and Material Properties

This activity is a great way to explore material properties like flexibility, durability, and biodegradability. Compare your bioplastic ornaments to other materials, like clay or traditional plastics. Discuss how sustainable materials can solve problems in the real world, from reducing pollution to creating better packaging.