topic 10 - using resources (1. properties and uses of materials) Flashcards
what are the properties of ceramics
what are the properties of ceramics
non metallic solids high melting point brittle excellent insulators
types of ceramics
clay ceramics
glass
what is clay ceramics
a soft material that can be moulded into different shapes which when fired at high temps it hardens to form clay
what is clay ideal for
pottery and bricks
properties of glass
transparent
moulded when hot and can be brittle when thin
how is glass made (soda lime glass) made
heating a mixture of limestone sand sodium carbonate until melts when cools it produces glass
what are composites made of
one material embedded in another
fibres or fragments of a material are surrounded by a matrix acting as a binder
what is the difference between borosilicate glass and soda lime
borosilicate has a higher melting point but made in same way but with sand and boron trioxide
examples of compositises
wood
fibre glass
carbon fibre
concrete
properties of wood
cellulose fibres held together by ligim
versatile giving trees strength
valued building material
properties of fibre glass
low density but very strong so used for things like skies
what are polymers
large molecules formed when monomers join together held together by strong covalent bond
what are properties of polymers
insulators of heat and electricty
flexible
easily moulded
properties mean have lots of applications including clothing
what do the monomer a polymers made from determine
the type of forces between the chains
what are thermosoftening polymers
individual tangled chains of polymers with weak forces between chains making them flexible
what are thermosetting polymers
chains with crosslinks between meaning it doesn’t melt when heated it only chars
strong hard rigid
how is a low denisty poly(ethene) made
by heating ethene to about 200 degrees under high pressure
flexible used for bags and bottles
how is a high density poly(ethene) made
lower temp and pressure with a catalyst
rigid used for water tanks and drain pipes
