Materials and properties Flashcards
What are ceramics
Non metals with high melting points that aren’t made from carbon based compounds
What can some ceramics be made from and what is this
Clay and glass
Clay is a soft material when it’s dig up from the ground so can be moulded into different shapes
Glass is a transparent material that can be moulded when hot and be brittle when thin
How does clay turn into a ceramic
It’s fired at high temperatures and hardens
What is most glass and how is this made
Soda lime glass
Made by heating a mixture of limestone sand and sodium carbonate until It melts and cools
How do you make borosilicate glass
By heating a mixture of sand and boron trioxide until it’s melts and cools
What is a composite
One material embedded with another
Fibres or fragments of a material are surrounded by a matrix acting as a binder
How is fibre glass a composite and how can it be used
It consists of fibres or glass embedded in a matrix made of polymer
It has low density but very strong
Used for things like skis surfboards and boats
How does a carbon fibre composite have a polymer matrix
What are there uses
Long chains of carbon atoms bonded together or carbon nanotubes
They are very strong and light
Used in aerospace and sports car manufacturing
What is an aggregate
Any material made from fragments
Usually like sand and gravel make up concrete to be an aggregate
What is concrete made from
Aggregate (sand and gravel) embedded in cement
It’s very strong
And ideal for building material Like skate parks
What is wood
A natural composite of cellulose fibres held together by an organic polymer matrix
What can influence the properties of a polymer
How is made and what it’s made from
What do they prpperies of polyethene depend on
The catalyst that was used and the reaction conditions like temperature and pressure
What’s the difference in low density and high density polythene
LD = made from ethene at moderate temp under high pressure - it’s flexible and used for bags HD = made from Ethene at lower temp and pressure with different catalyst - more rigid and used for drainpipes
What determines the properties of a polymer
The monomers that make up a polyester determine the type of bonds that form in it and the weak bonds between the molecule chains
