USING RESOURCES Flashcards
what are ceramics
ceramics are non metal solids with high melting points that aren’t made from carbon based compounds
what can ceramics be made out of
clay
examples of ceramics
clay and glass
clay
can be moulded into different shapes as it is soft when its dug up from the ground
when its fired at high temperatures it hardens to form a clay ceramic
glass
is transparent
can be moulded when hot and can be brittle when thin
what is most glass
soda lime glass
how is soda lime glass made
it is made by heating a mixture of limestone, sand and sodium carbonate until it melts
when the mixture cools it comes out as glass
what is borosilicate glass
it has a higher melting point than soda lime glass and it is made in the same way as soda lime glass
it is made using a mixture of sand and boron trioxide
what are composites
are made of one material embedded in another. fibres or fragments of a material are surrounded by a matrix acting as a binder
what do the properties of composite’s depend on
depends on the matrix/binder and the reinforcement used to make them
examples of composites
fibreglass
carbon fibre
concrete
wood
what does fibre glass consist of and what are its properties and what is it used for
glass embedded in a matrix made of polymer. it has a low density but is very strong
it is used for things like skis boats and surfboards
what does carbon fibre consist of and what are its properties and what is it used for
they have a polymer matrix and the reinforcement is made from long chains of carbon atoms bonded together
they are very strong and light
they are used in aerospace and sports manufacturing
what does concrete consist of and what are its properties and what is it used for
is made from aggregate embedded in cement
its very strong
this makes it ideal for use as a building material eg in skate parks
what does wood consist of and what are its properties and what is it used for
natural composite of cellulose fibres held together by an organic polymer matrix
what two things influence the properties of a polymer
the catalyst that was used and the reaction conditions (the temperature and pressure) that it was made under
example of the two things that affect a polymer
eg low density polyethene- is made from ethene at a moderate temperature under a high pressure and with a catalyst === its flexible and is used for bags and bottles
high density polyethene is also made from ethene but at a lower temp and pressure with a different catalyst
its more rigid and is used for water tanks and drainpipes
what are thermosoftening polymers
they contain individual polymer chains entwined together with weak forces between the chain.
you can melt these plastics and remould them
what are thermosetting polymers
contain monomers that can form cross limks between the polymer chains, holding the chain together in a solid structure.
these polymers don’t soften when theyre heated
theyre strong hard and rigid
examples of clay ceramics
porcelain and brick
what are polymers
insulators of heat and electricity, they can be flexible and easily moulded
they have many applications including in clothing and insulators in electrical items
metals
are malleable, good conductors of heat and electricity, ductile, shiny and stiff
what the problem with pure metals
theyre too soft
why are alloys better than pure metals
alloys are much harder than pure metals as they are a mixture between two or more metals or a metal and another element pure metals are too soft