Making our own environmentally friendly plastic in 6th class! (R.10)

We are studying our environment and the impact that we have on our environment in 6th class. It is currently "Plastic Free Week" in school and we are making a conscious effort to avoid using non-biodegradable and non-reusable plastic in school.
We have been using alternatives in school and we actually made our own biodegradable plastic from milk and vinegar which is environmentally friendly!