Materials Flashcards
What does synthetic mean?
man-made
Give examples of synthetic materials
polyamide, polyester, viscose
What raw material are most plastics and synthetic fibres made from?
crude oil
What are some advantages and disadvantages of plastic?
polythene bags = protective, lightweight but easily ripped
carbon fibre = lightweight but non-biodegradable
polyutherane = soft , comfy but produces toxic fumes
What are the two main types of plastics?
thermoplastic = plastics which soften or melt when heated
thermosetting plastics = plastics which do not soften or melt when heated already SET doesn’t change form
When plastics burn, what is produced?
carbon dioxide and water
What harmful gas is produced if there is a limited supply of oxygen when the plastic is being burned?
carbon monoxide
Why is it bad that plastic is non-biodegradable?
it can harm the environment and animals, causes major litter problems and does not rot away
What is being done to improve plastic?
biodegradable plastics are being produced
What is a polymer?
a polymer is a very big molecule made from many small molecules (called monomers) which repeat through the structure
What is the process called when monomers join together?
addition polymerisation
How are unsaturated monomers obtained?
catalytic cracking
What is the simplest monomer?
ethene C2H4
What happens to the double bond during the addition polymerisation process?
the double bond breaks
What are some facts about monomers? State how reactive they are, their size, their bond type, their state, expense and use
monomers are very reactive, they are small molecules, they contain a carbon-carbon double bond so are unsaturated, they are usually in a liquid or gas form, they’re cheap to produce and of little use as they are
