Page 39 - Curriculum Visions Dynamic Book

monomer: a building block of a larger chain molecule (“mono” means one, “mer” means part).
polymer: a compound that is made of long chains by combining molecules (called monomers) as repeating units. (“Poly” means many, “mer” means part).
polymerisation: a chemical reaction in which large numbers of similar molecules arrange themselves into large molecules, usually long chains. This process usually happens when there is a suitable catalyst present. For example, ethene reacts to form polythene in the presence of certain catalysts.
vulcanisation: forming cross-links between polymer chains to increase the strength of the whole polymer. Rubbers are vulcanised using sulphur when making tyres and other strong materials.
 A tyre is a combination of layers of vulcanised rubber and textile, often incorporating steel wire. The design is for strength, durability and suppleness.
Unit of rubber
These sulphur “bridges” hold the rubber units together, thereby increasing the strength of the rubber. This is the secret of vulcanising.
Unit of rubber
Carbon
Hydrogen
Sulphur
Foam rubber
Foam rubber contains many air bubbles to make it spongy and lightweight. Its main use is for fillings in household furniture, mattresses and carpet backing.
The latex is frothed up to incorporate air and then vulcanised in such a way that water is not evaporated from the foam before the vulcanisation process is complete.
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