TERYLENE
These occur naturally in living things. Some examples of natural polymers are:
Natural rubber
Protein in meat, leather, silk, hair and fur
Carbohydrates in cellulose, starch and sugar
Natural polymers are made up of carbon, hydrogen, nitrogen and oxygen.
Natural rubber comprises the molecules of the monomer 2-methyl-1,3-butadiene, also called isopropene, joined together to form a long chain, as in:
picture
Protein is obtained by the combination of amino acid molecules which represent the monomer units.
picture
Carbohydrates are formed through the combination of glucose molecule which act as the monomer.
picture
Synthetic Polymers
Synthetic polymer is a polymer that is manufactured in industry from chemical substances through the polymerisation process. Through research, scientists are now able to copy the structure of natural polymers to produce synthetic polymers.
Plastics, synthetic fibres and elastomers are examples of synthetic polymers.
The raw materials for the manufacture of synthetic polymers are distillates of petroleum.
The two types of polymerisation are:
polymerisation by addition
polymerisation by condensation
Polymerisation by addition involves monomers with >C = C<>
Synthetic Fibre
Nylon and terylene are synthetic fibres which undergo the condensation polymerisation process.
These fibres resemble natural fibres but more resistant to stress and chemicals, and more long-lasting.
In both cases, water is eliminated during the polymerisation process.
Nylon
Picture Nylon is used to make
umbrellas
curtains
socks
carpets
nylon string and rope
toothbrush
comb and so on
Terylene
Picture Terylene is used to make
fishing nets
clothes (quick-dry, non-iron)
cassette and video tapes
Issue in using synthetic polymer
Synthetic polymers have multiple uses in daily life because of the following properties:
Light and strong
Cheap
Withstand corrosion and chemical reaction
Withstand action of water
Synthetic polymers are also used to replace natural polymers such as cotton, silk and rubber.
However, synthetic polymers cause environmental pollution.
Most polymers are not biodegradable . Polymers cannot be decomposed biologically or naturally by bacteria or fungi as in the case of other garbage. Thus, the disposal of polymers has resulted in environmental pollution because they remain in the environment forever.
Plastic containers and bottles strewn around become good breeding places for mosquitoes which cause dengue fever, or malaria.
The open burning of plastics gives rise to poisonous and acidic gases like carbon monoxide, hydrogen chloride and hydrogen cyanide. These are harmful to the environment as they cause acid rain.
Burning of plastics can also produce carbon dioxide, too much of this gas in the atmosphere leads to the `green house effect'.
The raw materials used to manufacture synthetic polymers are petroleum and its by-products. Petroleum is a non-renewable source of fuel which is fast diminishing from the earth's crust.
This problem can be overcome by the following ways:
Recycling polymers: Plastics can be decomposed by heating them without oxygen at 700°C. This process is called pyrolysis. The products of this process are then recycled into new products.
Inventing biodegradable polymers: Such polymers should be mixed with substances that can be decomposed by bacteria (to become biodegradable) or light (to become photodegradable) .
Nylon and terylene are synthetic fibres which undergo the condensation polymerisation process.
These fibres resemble natural fibres but more resistant to stress and chemicals, and more long-lasting.
In both cases, water is eliminated during the polymerisation process.
Nylon
Picture Nylon is used to make
umbrellas
curtains
socks
carpets
nylon string and rope
toothbrush
comb and so on
Terylene
Picture Terylene is used to make
fishing nets
clothes (quick-dry, non-iron)
cassette and video tapes
Issue in using synthetic polymer
Synthetic polymers have multiple uses in daily life because of the following properties:
Light and strong
Cheap
Withstand corrosion and chemical reaction
Withstand action of water
Synthetic polymers are also used to replace natural polymers such as cotton, silk and rubber.
However, synthetic polymers cause environmental pollution.
Most polymers are not biodegradable . Polymers cannot be decomposed biologically or naturally by bacteria or fungi as in the case of other garbage. Thus, the disposal of polymers has resulted in environmental pollution because they remain in the environment forever.
Plastic containers and bottles strewn around become good breeding places for mosquitoes which cause dengue fever, or malaria.
The open burning of plastics gives rise to poisonous and acidic gases like carbon monoxide, hydrogen chloride and hydrogen cyanide. These are harmful to the environment as they cause acid rain.
Burning of plastics can also produce carbon dioxide, too much of this gas in the atmosphere leads to the `green house effect'.
The raw materials used to manufacture synthetic polymers are petroleum and its by-products. Petroleum is a non-renewable source of fuel which is fast diminishing from the earth's crust.
This problem can be overcome by the following ways:
Recycling polymers: Plastics can be decomposed by heating them without oxygen at 700°C. This process is called pyrolysis. The products of this process are then recycled into new products.
Inventing biodegradable polymers: Such polymers should be mixed with substances that can be decomposed by bacteria (to become biodegradable) or light (to become photodegradable) .
