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Title: Polymers
Description: These notes are aimed at students who require knowledge on polymers, including the conditions needed to make them, the different types of polymers there are, how they are made and what properties they have. Information is also given on thermosoftening and thermosetting polymers.
Description: These notes are aimed at students who require knowledge on polymers, including the conditions needed to make them, the different types of polymers there are, how they are made and what properties they have. Information is also given on thermosoftening and thermosetting polymers.
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POLYMERS
Polymers are made from chemicals made from crude oil
...
As monomers join
together they produce a tangled web of very long chain molecules e
...
poly(ethene)
...
g There are two types of poly(ethene), both made from ethene monomers but
formed under different conditions
...
The conditions needed to make low density poly(ethene) are:
high pressures and a trace of oxygen – ethene is heated to about 200 Celsius
degrees
...
There
are weak intermolecular forces so there’s a low melting point and a weak material
overall
...
High
density poly(ethene) is made up of straighter poly(ethene) molecules which can
pack more closely together than branched chains
...
Q) Describe and explain the properties of thermosetting and
thermosoftening polymers
...
When they cool, thermosoftening polymers harden into a new shape, so these
plastics can be melted and remoulded
...
Thermosoftening polymers don’t have cross-linking between chains
...
Thermosetting polymers are strong, hard and rigid
...
Thermosetting polymers have crosslinks which hold the chains together in a
solid structure
...
When the polymer cools down the intermolecular
forces bring the polymer molecules back together so the polymer hardens again
...
The strong bonds hold the
polymer chains in position
Title: Polymers
Description: These notes are aimed at students who require knowledge on polymers, including the conditions needed to make them, the different types of polymers there are, how they are made and what properties they have. Information is also given on thermosoftening and thermosetting polymers.
Description: These notes are aimed at students who require knowledge on polymers, including the conditions needed to make them, the different types of polymers there are, how they are made and what properties they have. Information is also given on thermosoftening and thermosetting polymers.