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Hello, my name is Mrs. Mehrin and I'm so excited to be learning all about bioplastics with you today.
Welcome to today's lesson from the unit properties, changes and separating materials.
Your learning outcome is, I can describe how long it takes for plastics to decompose and how to make an alternative degradable bioplastic.
Now, I know that learning can sometimes be a little bit challenging, but that's okay because it just means that we're going to work really hard together and we're going to learn loads of new things.
Let's begin.
So here are your keywords for today's lesson.
Now I am going to be referring to these keywords throughout today's lesson.
However, if you find it helpful, you can pause the video here and you can jot these down.
Off you go.
Fantastic, well done.
So our lesson today is split into two parts.
We've got plastic in our lives and the future of plastic.
Let's begin with the first part, plastic in our lives.
So plastic is a very useful material.
When produced, it can be melted, rolled, or squashed into a huge range of shapes and can be made in many colours.
And here are just a small selection of products that we can make using plastic.
So you've got your plastic containers, plastic bottles for your household goods.
You might use plastic bags or clingfilm, which is made of plastic, some of your favourite beach toys, may be made from plastic.
You've got your bins as well, which are made of plastic.
And then we have this floaty here as well, which is made from plastic.
So plastic has got so many fantastic uses.
And there are many different types of plastic with different properties.
Plastic products are often lightweight, strong, durable, and low-cost.
Now, where do you use plastic in your life? I'll give you five seconds to think about your answer.
Off you go.
Fantastic, well done.
So some plastic is designed to be reused lots of times like plastic toys or plastic furniture.
So you wouldn't just use these once and then throw them away.
But some plastic is designed to be used once, then thrown away or disposed of like plastic bottles.
And this is called single-use plastic.
The production of single-use disposable plastic containers and packaging has created a huge waste problem.
And some materials like fruit, vegetables and other food decompose quickly in a few days or weeks.
They are called degradable, which means they can be broken down or decomposed into the simple parts that made them.
Now, if living things help the process of decomposing, we say they are biodegradable.
The prefix bio means of living things.
So other materials like hard wood do decompose and are degradable, but it can take years for the process to happen.
Now plastic takes up to 500 years to decompose, and most plastics are not biodegradable because it's not a natural process when they decompose.
So things like plastic bags, before, were designed to just be used once and then thrown away.
But now when you go to the shops, you'll notice that they have something called Bags for Life.
And this just means that you can keep using that plastic bag until it tears, and then you can swap it for a new one.
Now, discarded plastics are causing problems in our seas and on our land for animals, including humans.
Jacob says, what sort of problems can discarded plastic cause? Well, wildlife can get caught in it, animals might eat it and make them very, very sick.
And it pollutes the environment.
And you might have noticed it happening more and more when you go to the beach, for example, and you might see plastic that's been washed up on the shores.
And fish in the oceans and the seas are now starting to eat plastic.
And so when scientists are doing research, they're finding that fish contain plastic, which means that when we eat the fish, we're also eating some of that plastic too.
So it's really harmful for the environment and for us.
Now, can you remember how long it takes for plastic to decompose? Was it, A up to five days, B up to five weeks, C up to five years, or D up to 500 years.
I'll give you five seconds to think about your answer.
Off you go.
Fantastic, well done.
The answer is D, up to 500 years.
Now, discarded plastics cause problems in something and something for animals, including humans.
Now there are two different answers for this.
So are the answers, A in our houses, B in our seas, C in our schools, or D on our land? I'll give you five seconds to think about your answer.
Off you go.
Fantastic, well done.
The answers are in our seas and on our land.
Now, here is your first task for today, and it says, research how long it takes for these different objects to decompose.
So we have paper, banana peel, cotton fabric, plastic bag, aluminium can, and a plastic bottle.
So I'd like you to pause the video here and have a go at doing this activity.
Off you go.
Fabulous, well done.
So paper can take two to six weeks, which isn't that long, banana peel, three to four weeks, cotton fabric, one to five months, a plastic bag, 10 to 20 years, an aluminium can over 80 years, and a plastic bottle hundreds of years.
Now, many scientists have researched how long it takes for objects to decompose, and your research may show slightly different amounts of time.
So, we are now onto the second part of our learning, which is the future of plastic.
Now, some types of plastic can be recycled.
That means it can be sorted, cleaned, cut into small pieces, melted, and then reshaped into new products.
Recycling plastic is one way to reduce plastic waste, and this also reduces the amount of new plastic which is being made.
Laura says, if we all recycle our plastic, will we solve the problem of plastics? Now, recycling is really important as it helps to reduce waste and the production of new plastic.
But unfortunately, not all types of plastic can be recycled yet.
And you can tell whether or not a plastic can be recycled by having a look at the label and it'll tell you whether or not it can be.
So to help reduce plastic waste, scientists are investigating ways to make plastic that is biodegradable.
Now, biodegradable bags, packaging, and disposable cutlery are made to last long enough for their use, then degrade naturally.
And here we have a biodegradable bag.
Now even surgeons are now using biodegradable stitches that break down in your body over time.
Now the waste created is not the only problem with our use of plastic.
Traditional plastic is made from crude oil.
And Sam says, I have learned that oil is a type of fuel called a fossil fuel.
Now, fossil fuels are made from fossilised plants and animals over millions of years buried deep beneath Earth's surface.
And here we've got coal, natural gas and oil.
Now there are limited amounts of fossil fuels beneath Earth's surface, which take millions of years to form.
Do you know any problems that are associated with fossil fuels? I'll give you five seconds to think about your answer.
Off you go.
Fantastic, well done.
So, because fossil fuels take millions of years to form, we are using them far quicker than they are forming, and that means that we are running out of them.
Another concern is that using fossil fuels to make plastic produces harmful gases which contribute to something called global warming.
So instead of using oil, scientists have discovered how to use alternative materials to make plastic.
Now bioplastics are plastics made from materials which come from sustainable sources such as plants.
So these are much better because once you've used the plant to make the plastic, you can grow it again, and that takes a lot less time than it takes for fossil fuels to be formed.
Sam says sustainable sources are those which will never run out or that we can easily grow more of.
Now, some plants such as potatoes, corn, peas, and beans contain starch.
Now scientists extract starch from potatoes using mixing, filtering and evaporation.
And corn flour is starch removed from corn kernels in the form of a fine white powder, often used for cooking, and it's often used to thicken sauces.
Now, what can bioplastics be made from? Is it A, fossil fuels, B, starch or C, metal? So I'll give you five seconds to think about your answer.
Off you go.
Fantastic, well done.
The answer is B, starch.
Now, scientists are trying to tackle the two major problems that come with the use of traditional plastics.
So one, plastic waste not being degradable, and two, using fossil fuels to produce plastic.
Now the development of biodegradable plastics aims to address the first problem, which is that plastic waste is not degradable.
Now the development of bioplastics aims to address the second problem.
So you don't need to use fossil fuels anymore to produce the plastic.
Now the ideal bioplastic needs to be durable, lightweight, and flexible enough to replace traditional plastic, and you need to be able to mould it to make objects of different shapes fit for purpose.
Now, the ideal bioplastic would also be degradable, so that you're not having to wait up to 500 years in order for it to degrade or decompose.
Now, it should decompose over time without leaving the plastic pollution that is causing problems in our seas and on our lands.
Now, scientists can observe the bioplastics over time to find out how long it takes them to decompose, and they use their findings to help them improve their recipes for plastics.
And in this way, scientists are continuing to work towards the perfect bioplastic, which would not rely on fossil fuels and not contribute to plastic pollution.
So why do scientists observe bioplastics over time? Is it A, to find out how their colour changes over time, B, to find out which animals use them as habitats, or C, to find out how long it takes them to decompose.
So I'll give you five seconds now to think about your answer.
Off you go.
Fantastic, well done.
The answer is C, to find out how long it takes them to decompose.
So here is task B, and it says to make your own bioplastic using corn flour as starch.
So you're going to mix corn flour, vinegar, glycerin, and water together in a beaker, and then you're going to pour the mixture into a small saucepan and ask an adult to heat it whilst stirring.
Now the second step should only be done by an adult because it's not safe for you to do it without an adult doing it.
So after a few minutes, the mixture should get thicker.
So when it does, you need to ask the adult to spread the mixture onto a small plate.
And you're going to leave the plate in a warm place for a couple of days and then it's going to harden.
So I'd like you to pause the video here and have a go at doing this.
So you can flick back in this video between the first slide and this slide.
Off you go.
Fantastic, well done.
So to make your own bioplastic using corn flour as starch, you had to follow four steps.
So once your mixture had dried, your bioplastic may have looked like this.
So our bioplastic was solid and clear, and it was flexible to start with, but then broke in half when we played with it a lot because it dries out at that point.
So let's go on to the summary of your learning today.
So it takes up to 500 years for plastics to decompose.
Discarded plastics are causing problems in our seas and on our land for animals, including humans.
Scientists have discovered ways to make bioplastics or biodegradable plastics.
Bioplastics can be made from starch and scientists can observe the bioplastics over time to find out how long it takes to decompose.
Now, I'm so proud of your fantastic learning today and for you making those bioplastics.
I hope you had a lot of fun in doing that, and I hope you have learned lots of fabulous new things today.
Well done.