APPLICATIONS OF POLYMERS:
o Synthetic polymers are produced from finite resources such as coal, gas and oil
o Natural polymers come from a variety of sources such as rubber and amber, which
come from tre es
Thermoplastics can be formed using heat and reshaped many times without changing
properties
LDPE:
derived from ethylene
quite flexible + tough
used in packaging where flexibility is required like squeezy bottles and snap on lids, carrier bags and
toys
can be either translucent or opaque
has excellent resistance to chemicals
LDPE film is also combined with board
and aluminium foil to make packaging
laminates
HDPE
tough + has a higher strength to weight ratio than LDPE
commonly used for bottles and drums containing chemicals, rigid plastic toys, storage boxes,
buckets
sometimes simply referred to as ‘polythene’
harder than LDPE but also has good chemical resistance
Nylon:
used for mechanical components such as machine screws and gears + woven textiles such as rope,
parachutes, tents, seat belts and carpets
has a low coefficient of friction
durable + resistant to abrasion
heat resistant
PMMA (acrylic) :
tough lightweight material
clarity in transparent form means is often used as a lightweight shatter-resistant alternative to
glass
o for shower trays, baths, car lamp covers and lenses in glasses
can be a clear plastic but is available in a very wide range of colours
relatively poor resistance to chemicals
Thermosetting plastics cannot be reshaped using heat.
Thermosets:
more brittle than thermoplastics + are best suited to stiffer mouldings
very hard + waterproof when solid, making them ideal for use as adhesives
more difficult to mould and cannot be reheated and reshaped
retain their shape well at high temperatures
Epoxy resin:
a clear resin that needs to be mixed with a catalyst to cure
o Synthetic polymers are produced from finite resources such as coal, gas and oil
o Natural polymers come from a variety of sources such as rubber and amber, which
come from tre es
Thermoplastics can be formed using heat and reshaped many times without changing
properties
LDPE:
derived from ethylene
quite flexible + tough
used in packaging where flexibility is required like squeezy bottles and snap on lids, carrier bags and
toys
can be either translucent or opaque
has excellent resistance to chemicals
LDPE film is also combined with board
and aluminium foil to make packaging
laminates
HDPE
tough + has a higher strength to weight ratio than LDPE
commonly used for bottles and drums containing chemicals, rigid plastic toys, storage boxes,
buckets
sometimes simply referred to as ‘polythene’
harder than LDPE but also has good chemical resistance
Nylon:
used for mechanical components such as machine screws and gears + woven textiles such as rope,
parachutes, tents, seat belts and carpets
has a low coefficient of friction
durable + resistant to abrasion
heat resistant
PMMA (acrylic) :
tough lightweight material
clarity in transparent form means is often used as a lightweight shatter-resistant alternative to
glass
o for shower trays, baths, car lamp covers and lenses in glasses
can be a clear plastic but is available in a very wide range of colours
relatively poor resistance to chemicals
Thermosetting plastics cannot be reshaped using heat.
Thermosets:
more brittle than thermoplastics + are best suited to stiffer mouldings
very hard + waterproof when solid, making them ideal for use as adhesives
more difficult to mould and cannot be reheated and reshaped
retain their shape well at high temperatures
Epoxy resin:
a clear resin that needs to be mixed with a catalyst to cure
