Overview

In this activity, you will learn how to make bioplastic decorations using simple ingredients that you can find in larger supermarkets or order online. You may have some at home already.

There doesn’t need to be a special festival like Christmas or Valentine’s Day to make decorations. During these extraordinary times, how about making a rainbow, heart, or star-shaped decorations to celebrate our loved ones, friends, carers, health workers and all those making a difference to other people’s lives.

Using simple ingredients, make your own bioplastic, and then use moulds to create celebratory shapes and hang these in your window or outside. Celebrating the love and kindness of thousands around the world need not cost the earth.

In the find out more section, we discuss the wider implications of using bioplastics for other purposes.

Activity steps

1. Add the cornflour, water, glycerol and vinegar to a saucepan. Suggested amounts are listed in the What you’ll need section, but the important thing is that the ratio should be 12 parts water, 3 parts cornflour, 1 part glycerine, 1 part vinegar.
2. Stir all the ingredients together to remove any lumps.
3. Place the saucepan on a stove on a low to medium heat. As you heat the mixture, it should turn from being thin and milky to becoming thicker and clearer.
4. Heat for about 10 to 15 minutes at a gentle boil, but be careful not to overheat as this could cause your bioplastic to become lumpy. You can add food colouring towards the end of this stage.
5. Your bioplastic should be like a very viscous liquid. You can pour or use a spatula to place your mixture on a sheet of greaseproof paper. Also, take the opportunity to get rid of any air bubbles with a toothpick.
6. You can shape your plastic in a couple of ways. Pour or scrape into a cookie cutter or silicone mould, or wait for 30 minutes to one hour and use a cookie cutter to cut out a shape.
7. As you are forming your shapes (perhaps hearts or stars) also make a hole to thread a ribbon or string to hang your decoration.
8. Leave your decoration to dry fully overnight or preferably for a good day or so.
9. Once your decoration is dry, you can paint it and write on it to give love and thanks to all those helping others.
10. Hang your decoration in a window or outside to show your thanks and take a picture to share on social media. Please tag us @commonseas and use the hashtag #SeaChampions so we can say thank you too.

Activity materials

• 4 tablespoons water
• 1 tablespoon cornflour (also known as corn starch)
• 1 teaspoon clear vinegar
• 1 teaspoon glycerine (also known as glycerol - found in the baking section of a supermarket)
• Saucepan and stove
• Greaseproof paper (also known as baking parchment)
• Silicone moulds or cookie cutters
• Toothpick
• Paint and pens (optional)
• String or ribbon

As bioplastics are made using natural ingredients, they are more readily biodegradable. For this activity, we are using corn flour as the starch (polymer), water (as a solvent), vinegar (as the acid) and glycerine (as the plasticiser to make the bioplastic more flexible).

However, for bioplastics to be effective, they often have to be tough and durable. You cannot have a replacement plastic bag that will dissolve in the rain or fall apart in minutes. The problem is that if you make bioplastics less ready to degrade, they can present the same problems in the environment as synthetic plastics.

When an item is described as biodegradable, people can think that decomposition will occur in a manner of days or weeks. However, research conducted by Plymouth University has shown that biodegradable bags can still hold shopping three years after being discarded.

This means that bioplastics can still have similar environmental impacts to petroleum-based plastics if they are durable in the ocean. 'Bio' or 'eco' alternatives to single-use plastic items often have their own environmental impacts. Using a single-used paper cup every day requires resources and energy to make, even if it is not using plastic. A better solution is to consider the 6 Rs, and look to refuse rather than replace single-use items with another material that could have environmental impacts both in terms of resource use and impact on the marine environment if not disposed of properly.