C10 Flashcards
What are ceramics and examples?
Ceramics are non-metal solids with high melting points that arent made from carbon-based compounds.
-Clay
-Glass
How are clay ceramics made?
Clay ceramics are made by shaping wet clay and heating in a furnace.
What makes clay ceramic ideal for pottery and bricks?
Ability to be moulded when wet and harded.
How is glass made?
By heating a mixture of sand,sodium carbonate and limetsone. The molten liquid then cools and solidifies.
What is most of the glass we use called and whats it used for?
Sode-lime glass- window paines,glass jars and bottles.
What is borosilicate glass made from and whats it used for?
Borosilicate glass-made from sand and boron trioxide.
Baking and laboratory.
What has a higher melting point borosilicate glass or soda lime glass and why is that better suited to its function?
Borosilicate has a higher melting point than soda-lime glass which makes it better suited to its function where high temps are used.
What do the properties of polymers depend on?
What monomers they are made from and which conditions they are made in.
How are low dentisty and high density poly(ethene) both produced from ethene?
Low density poly(ethene) is made from ethene at a moderate temperature under a high pressure.
High density poly(ethene) is made from ethene but at a lower temperature and pressure with a catalyst.
Uses of low and high density poly(ethene)?
Low- flexible so used for bags and bottles
High-more rigid so used for water tanks and drainpipes.
What is the difference between thermosoftening and thermosetting polymers?
Polymer chains in thermosetting plastics are held together by strong crosslinks these plastics can withstand higher temps and dont melt when heated (high melting points).
Thermosoftening have weaker forces between the chains and can be melted and remoulded.
What are composites made of?
Two materials, a matrix surrounding and binding together fibres or fragments of the other material (reinforcment).
Examples of composities?
-Wood
-Concrete
-Fibreglass
-Carbon fibre
What does fibreglass consist of,properties and uses?
Fibres of glass embedded in a matrix made of polymer (plastic).
It has a low density (like plastic) but is very strong (like glass).
Used for skis,boats and surfboards.
What does carbon fibre composites consist of,properties and uses?
Also have a polymer matrix.
The reinforcements either made from long chains of carbon atoms bonded together (carbon fibres) or from carbon nanotubes.
Very strong and light- used in aersopsace and sports car manafacturing.
What is concrete made from,property and use?
Concrete is made from sand and gravel embedded in cement.
Very strong- used as building material.
What is wood a composite of?
Wood is a composite of cellulose fibres held together by an organic polymer matrix.
Properties of ceramics?
Glass and Clay ceramics (porcelain and bricks). Theyre insulators of heat and electricity,brittle (break easily) and stiff
Properties of polymers and uses?
Polymers are insulators of heat and electricity and are flexible (bent without breaking) and are easily molded.
Clothing and insulators in electrical appliances.
Properties of metals and uses?
Metals are malleable, ductile, good conductors of heat and electricity,shiny and stiff.
Electrical wire, car body-work and cutlery.
What are most metals in everyday use?
Alloys
What is bronze an alloy of and uses?
Bronze is an alloy of copper and tin.
Uses-coins,medals,statues
What is brass an alloy of + uses?
Copper and zinc.
Uses- locks,taps, door knobs
What is gold an alloy of and uses?
Gold alloy of silver,copper and zinc.
Used in jewellery.Proportion of gold measured in carats. 24 caract=100% pure gold
18 carat = 75% gold
