Ch 2. Plastics Flashcards
What do the properties of plastics determine?
How the plastic will be made and the uses it will have in our everyday lives.
Name four common plastics.
- PVC
- Polystyrene
- Polythene
- Polypropene
What properties does PVC plastic have?
Flexibility, and electrical insulator.
What properties does Polystyrene have?
Light, poor conductor of heat.
What properties does Polythene have?
Light, unreactive, hard-wearing.
What properties does Polypropene have?
Strong, High elasticity.
What is PVC used for?
electric cable
What is polystyrene used for?
Hot drinks cups, packaging
What is polythene used for?
Kitchen bowls, basins, and buckets.
What is polypropene used for?
Carpet fibres, ropes.
What is a thermoplastic (or thermosoftening plastic)?
A plastic which softens or melts on heating and hardens on cooling. These can be reshaped.
Give 4 examples of thermoplastics.
- PVC
- Polystyrene
- Polythene
- Polypropene (or polypropylene)
What is a thermosetting plastic?
A plastic which does not soften or melt on heating.
Give 2 examples of thermosetting plastics and their uses.
Bakelite - used for making electrical plugs and sockets.
Formica - used to make kitchen worktops.
What is the advantage of using PVC instead of traditional materials? Use examples in your answer.
In gutters, it is more beneficial than using metals because it is lighter and does not corrode.
In window frames, it is better than wood because it does not rot or require painting.
*Please note: Plastics are also beneficial because they are cheap.
What is the advantage of using plastics in carpet production?
Plastics such as: - Nylon - Polyester - or Polypropene fibres are better in carpet production than traditional wool because they are harder wearing.
What is the disadvantage of using plastics in carpet manufacture?
They are not so warm or soft.
Why is plastic production disadvantageous?
Huge quantities of plastics are thrown away, and since most of them are non-biodegradable, they harm the environment via pollution.
How can plastic pollution be overcome?
- Recycling
- Burning waste plastics - this would provide energy, but would mean that plastics would be lost as a source of raw material. This could also be harmful to the environment as some plastics burn to release toxic chemicals, which just add to the pollution.
How can plastics be recycled?
The plastics are collected and processed to form chemicals which can then be used for new plastic products.
Give an advantage of burning plastics?
It provides energy.
What are the disadvantages of burning plastics?
Plastics would be lost as a source of raw material.
This could also be harmful to the environment as some plastics release toxic chemicals when burned.
What can all plastics CONTAINING CARBON burn to produce, if burned in a LIMITED AIR SUPPLY?
Carbon monoxide.
What does PVC burn to produce?
Hydrogen chloride
What does polyurethane burns to produce?
Hydrogen cyanide gas (poisonous).
Name a common plastic that is used in everyday life.
Poly(ethene)
What is poly(thene)?
A polymer made from the monomer ethane.
It is the simplest member of the alkene family.
What are plastics made of? How are they made?
Most plastics are synthesised resources (man made by scientists) with chemicals obtained from crude oil. However, they can also be obtained naturally from the environment.
What are plastics?
These are examples of polymers, which are very large molecules formed by joining together lots of smaller molecules called monomers.
What are the uses of plastics determined by?
Their chemical properties.
How are polymers named? Give an example.
The name of the polymer comes from the name of the monomer used to make it.
For example: monomer ethene is used to to make polymer poly(ethene).
*Please note, the monomer is always put in brackets, with ‘Poly’ as its prefix, when naming polymers.
What is the name of the plastic made from propene?
Poly(propene)
What is the name of the monomer used to make poly(penylethene)?
Penylethene
What is polymerisation?
The process which involves the smaller monomer units joining together to form a larger polymer molecule.
What is addition polymerisation?
Addition polymerisation is a process involving many small, unsaturated monomers combining to form one large polymer molecule.
Name two important feedstocks in the petrochemical industry and state a way in which they can be used.
The alkenes; ethene and propene
are used to make addition polymers.
In what shape are monomers drawn?
In an H shape.
How are polymers drawn from a monomer?
The monomer (in an H shape) has a double bond. The double bond is broken, and the monomer then acts as a repeating unit, being joined up by the open double bonds to form a larger molecule - a polymer.
How can a monomer in a polymer be identified from the full structural formula?
The monomer is the repeating unit, with a double bond.
How do we know that a polymer was formed by a addition polymerisation and not condensation polymerisation?
As the backbone of the polymer has only carbons, in the full structural formula.
How can plastics be made or found naturally?
They can be synthesised in nature and even in our bodies.
Give examples of natural polymers?
Carbohydrates such as:
- Starch
- Proteins
What is the name of the monomer which makes up starch (polymer)?
Glucose.
What physical property do plastics have in common?
They are pliable or able to be moulded.
How is crude oil used to make plastics?
- It undergoes fractional distillation to form naptha.
- And then some of the longer chain fractions undergo catalytic cracking to form alkenes.
- And then the alkenes undergo addition polymerisation to form plastics.
Summarise the main chemical properties that plastics have in common with each other.
- Easily moulded into different shapes
2. Good Insulators of both heat and electricity.
