Everything Science Grade 12

(Marvins-Underground-K-12) #1

CHAPTER 2. ORGANICMACROMOLECULES 2.5



  • Polyvinylchloride (PVC)
    Polyvinyl chloride (PVC) (figure 2.8) is used inplumbing, gutters, electronic
    equipment, wires and food packaging. The sidechains of PVC contain chlorine
    atoms, which give it itsparticular characteristics.


C C


H


H


Cl

H


n

Figure 2.8: Polyvinyl chloride

FACT


Many vinyl products
have other chemicals
added to them to
give them particular
properties. Some of
these chemicals, called
additives, can leach out
of the vinyl products.
In PVC, plasticisers are
used to make PVC more
flexible. Because many
baby toys are made from
PVC, there is concern
that some of these
products may leach into
the mouths of the babies
that are chewing on
them. In the USA, most
companies have stopped
making PVC toys. There
are also concerns that
some of the plasticisers
added to PVC may cause
a number of health
conditions including
cancer.


  • Synthetic rubber
    Another plastic that wascritical to the World War 2 effort was synthetic rubber,
    which was produced ina variety of forms. Not only were worldwidenatural
    rubber supplies limited,but most rubber-producing areas were under Japanese
    control. Rubber was needed for tyres and parts of war machinery. After the war,
    synthetic rubber also played an important part inthe space race and nuclear arms
    race.

  • Polyethene/polyethylene (PE)
    Polyethylene (figure 2.1) was discovered in 1933. It is a cheap, flexible and
    durable plastic and is used to make films and packaging materials, containers and
    car fittings. One of themost well known polyethylene products is ’Tupperware’,
    the sealable food containers designed by Earl Tupper and promoted through a
    network of housewives!

  • Polytetrafluoroethylene (PTFE)
    Polytetrafluoroethylene(figure 2.9) is more commonly known as ’Teflon’ and is
    most well known for itsuse in non-stick frying pans. Teflon is also usedto make
    the breathable fabric Gore-Tex.


C C


F


F


F


F


C C


F


F


F


F


n

Figure 2.9: A tetra fluoroethylene monomer andpolytetrafluoroethylenepolymer

Table 2.1 summarises the formulae, properties and uses of some of the most common
plastics.

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