Hello, my name's Mrs. Taylor.

I'm really pleased you can join me for the lesson today.

The title of our lesson today is Polymer Properties and Processes, and this is part of the Product Analysis: Encouraging Healthy Lifestyles unit.

Let's begin.

The outcome is I can identify and justify the material and process used for a polymer product.

We have several keywords today.

Synthetic, which means manufactured, not naturally occurring.

Biodegradable, which means decays naturally.

Fractional distillation, which is the separating component parts of a mixture.

And polymerization, chemically combining small molecules called monomers to form long-chain structures called polymers.

Let's begin.

We have three learning cycles: sources of polymers, properties and applications of polypropylene, and injection moulding.

We'll begin with sources of polymers.

Let's go.

The word polymer comes from the Greek words many and parts.

Polymers are long, flexible chains of chemical compounds made up of many monomers.

Monomers are lots of small molecules, and polymers are long chains of monomers.

Polymers can occur naturally or be manufactured.

Natural polymers are sourced direct from nature, such as rubber plants.

Manufactured polymers are known as synthetic.

Synthetic polymers can be made from renewable sources or non-renewable sources.

Let's have a check.

True or false? Polymers are all synthetic.

Pause the video.

Have a go.

Well done.

Let's have a look.

That's right.

It's false.

Synthetic means manufactured, rather than naturally occurring.

There are some naturally-occurring polymers, such as rubber from a rubber plant.

Most polymers are, however, synthetic.

Biodegradable polymers are made from renewable sources, such as sweet potato starch.

Most polymers are made from non-renewable petrochemicals.

Petrochemicals include natural gas and crude oil.

Let's have another check.

Synthetic polymers are made from A, peat, B, crude oil, C, natural gas, or D, coal.

Pause the video.

Have a go.

Let's have a look.

That's right.

The correct answers are crude oil and natural gas.

This is a Biopol bag.

Biodegradable polymers are abbreviated to Biopol.

They are made from plant starch, which is renewable and sustainable.

They biodegrade after use, and therefore, do not create waste which needs to be disposed of.

This is a polymer citrus fruit juicer.

Polymers made from petrochemicals are made from non-renewable sources, which are not sustainable.

They do not degrade easily and create waste, which needs to be disposed of.

Most polymers made from petrochemicals can be recycled, but the quality is reduced.

Here, we have another check.

Why do polymers made from petrochemicals have a negative impact on the environment? Is it A, fossil fuels cannot be replaced, B, they biodegrade, or C, they create waste which needs to be disposed of? Pause the video and have a go.

Great, let's check.

That's right.

It's A, fossil fuels cannot be replaced, and C, they create waste which needs to be disposed of.

There are four main stages in the sourcing of polymers: extraction, refinement, cracking, and polymerization.

Extraction, obtaining the fossil fuels from within the Earth's crust on land or under the sea.

This is often damaging to the local environment.

The second stage is refinement, converting the fossil fuels into useful materials through fractional distillation.

This releases greenhouse gases.

Here, we have a check.

What is the first stage of the sourcing of polymers? A, polymerization, B, cracking, C, extraction, or D, refinement.

Pause the video and have a go.

That's right, extraction.

The third stage of sourcing polymers is cracking, breaking down the material into smaller, more manageable molecules known as monomers.

The fourth stage is polymerization, joining long chains of monomers to create polymers.

Let's have another check.

What is the final stage in the sourcing of polymers? A, polymerization, B, cracking, C, extraction, or D, refinement.

Pause the video and have a go.

That's right.

It's polymerization.

Well done.

Now, we move on to Task A.

Describe the four stages of sourcing polymers, and then describe how petrochemical polymers can have a negative impact on the environment.

Pause the video and come back to me when you're ready.

Well done.

Let's have a look at some of the answers.

Describe the four stages of sourcing polymers.

The first stage is crude oil or natural gas are extracted from the Earth's crust.

The second stage is through fractional distillation.

The oil or gas are converted into useful materials, such as propane.

The third stage, through the process of cracking, these materials are broken into more manageable molecules called monomers, such as propylene.

And the fourth stage is polymerization.

We're joining monomers to create polymers, such as polypropylene, which can then be made into products.

This second part of the task was to describe how petrochemical polymers can have a negative impact on the environment.

Sam says, "Fossil fuels once taken from the Earth cannot be replaced.

"The process of drilling also uses a lot of energy." And Izzy says, "Refining the petrochemicals uses a lot of energy, "and also pollutes the atmosphere with greenhouse gases." Well done.

Let's move on to the second learning cycle within our lesson today, properties and applications of polypropylene.

Polypropylene is a thermoforming polymer made from petrochemicals.

Thermoforming polymers: can be formed into complex shapes, have a relatively low melting point, can be recycled.

The physical and mechanical properties of polypropylene are shown in this table.

Physical properties include good heat and freeze resistance, good chemical resistance, and it is available in many different colours.

The mechanical properties include flexible, lightweight, and tough.

Polypropylene is used to create many different products.

For example, polypropylene outdoor seating, polypropylene carpets, and a polypropylene folder that you might see in your classroom.

Polypropylene is used to create many different products.

Polypropylene is suitable for outdoor seating because it has a high resistance to heat and freezing, which makes it good for outdoor use in all weathers.

As it is tough, it can also withstand the weight and impact of people sitting on it.

Let's have a check.

Which properties make polypropylene suitable for outdoor use? Is it A, good heat and freeze resistance, or B, available in many colours, C, lightweight, or D, flexible? Pause the video and have a go.

Okay, let's check.

Well done.

Good heat and freeze resistance.

Polypropylene is used to create many different products.

Polypropylene is suitable for carpets because it is available in many colours, which means users can choose one to suit their taste.

It is chemical resistant, which means it can have stain-proof treatments added, but also withstand cleaning products.

Let's have another check.

Why is chemical resistance an important property for carpets? Is it A, carpet is not damaged by cleaning products, B, the carpet is not damaged when stain-proof treatments are added, or C, the carpet is not damaged when hoovered? Pause the video and have a go.

Okay, let's check your answers.

That's right.

It's A and B.

The carpet is not damaged by cleaning products, and the carpet is not damaged when stain-proof treatments are added.

Here, we have another example of a polypropylene product.

This is a ring binder.

Polypropylene is suitable for folders because it is flexible and will not break when opened and closed.

It is also lightweight, which means it can be carried in a school bag easily.

And now we move on to Task B.

Explain what properties make polypropylene a suitable material for this citrus fruit juicer? Remember to link the properties to the product specifically.

Pause the video.

Have a go.

Well done.

Let's have a look at some of the answers you may have come up with.

Polypropylene is available in many different colours, which means the user can select a citrus fruit juicer to fit in with their kitchen aesthetic.

Lemon juice is an acid, so it is important that the material is resistant to chemicals, which polypropylene is.

As polypropylene is lightweight and tough, it is easy to move around the kitchen, but also will not break if dropped.

Well done.

Let's move on to the third learning cycle for today.

We now look at injection moulding.

Injection moulding is a reforming manufacturing process.

Injection-molded polymer products are characterised by complex shapes internally and externally, high-volume, high-speed production, they can be automated, there are high setup costs.

Now, we move on to a check.

What type of manufacturing process is injection moulding? Is it A, reforming, B, deforming, C, wasting, or D, fabricating? Pause the video.

Well done.

That's right.

It's reforming.

Injection moulding machines require a mould for each different product manufactured.

The moulds are made from stainless steel.

They require highly skilled workers to produce them, as they are complex with many curves and details.

This is also time-consuming and very expensive, which is why this process is not suitable for low volume production.

Here we have a check.

Which of these products has been injection moulded? Pause the video.

Okay, let's check.

That's right.

It's the remote control.

Here, we have a diagram of an injection moulding machine.

Let's have a look at some of the different parts.

Here is the hopper, where polymer granules and any necessary additives are placed, a heater jacket, a two-part mould, ejector pins, Archimedean screw, and a hydraulic ram.

True or false? The polymer granules are placed in a funnel.

Pause the video.

What did you think? That's right.

It's false.

The granules are placed in the hopper.

This is also where additives can be added, such as pigments, plasticizers, or fillers.

Now, we look at the injection moulding process.

The first thing that happens is the mould is made for a specific product.

The polymer granules are then placed in the hopper alongside any additives needed.

The third phase is the motor turns the Archimedean screw, which moves the granules along inside the machine.

As the granules pass through the heater jacket, they become molten.

The fifth part is when there is a collection of molten polymer at the end of the machine, the hydraulic ram forces the polymer into the mould.

The mould is cooled, and then the mould is opened, and the ejector pins push the solidified product out.

Here, we have Task C.

The first part is for you to label the diagram using the following words.

The second part is where you describe the process of injection moulding by filling in the blanks using these words.

And the third part is to explain why this citrus fruit juicer has been manufactured using the injection moulding process.

Pause the video and have a go.

Good luck.

Amazing work.

Let's have a look at your answers.

Did you get the labels correct? And here, we have the process with the blank words added.

A, the two-part mould is made for a specific product.

B, the polymer granules are placed in the hopper alongside any additives needed.

C, a motor turns the Archimedean screw, which moves the granules along inside the machine.

D, as the granules pass through the heater jacket, they become molten.

E, when there is a collection of molten polymer at the end of the machine, the hydraulic ram forces the polymer into the mould.

F, the mould is cooled.

And G, the mould opens, and the ejector pins push the solidified product out.

Here we have the answer to part three.

Explain why the citrus fruit juicer has been manufactured using the injection moulding process.

The citrus fruit juicer is suitable for injection moulding because many are made at once.

Polypropylene can be injection moulded.

The shape is complex with internal and external curves, which could not be made easily by other processes.

Well done.

Here is the summary of today's learning.

Polypropylene is a synthetic polymer created from petrochemicals.

The process creating polypropylene involves extraction, refinement, cracking, and polymerization.

Polypropylene is a versatile material used for different products.

Injection moulding is suitable for complex shapes with internal and external curves.

Injection moulding is a suitable process for large-scale production.

Thank you for joining me today.

Well done.