14.8 (a) Synthetic polymers
Uses of plastics:
Polymer | Example of uses |
polythene | plastic bags and gloves, clingfilm (low density), mugs,
bowls, chairs, dustbins (high density) |
polychloroethane (PVC) | water pipes, wellingtons, hoses, covering for electricity
cables |
polypropene | crates, ropes |
polystyrene | used as expanded polystyrene in fast-food cartons,
packaging, and insulation for roofs and walls |
Teflon | coated on frying pans to make them non-stick, fabric
protector, windscreen wipers, flooring |
nylon | ropes, fishing nets and lines, tents, curtains |
Terylene | clothing (especially mixed with cotton), thread |
Pollution problems from plastics:
-choke birds, fish and other animals that try to eat them. Or they fill up the animals’ stomachs so that they can’t eat proper food, and starve to death.
-they clog up drains and sewers and cause flooding.
-they collect in rivers, and get in the way of fish. Some river beds now contain a thick layer of plastic
-they blow into trees and onto beaches. So the place looks a mess. Tourists become put off.
Deduce the structure of the polymer product from a given alkene and vice versa (I just found as many as I could from the power points on moodle):
(For making nylon and Terylene: details of manufacture and mechanisms of these polymerisations are not required.) Making nylon (a polyamide):
The monomers are:
But they are represented like this:
No double bonds break. Instead, single bonds break, and new single bonds form. The monomers are able to join to each other by eliminating a small molecule: hydrogen chloride. This reaction continues at each the two monomers. Thousands of molecules join together, giving a macromolecule:
Making Terylene (a polyester): The monomers are:
The monomers join by eliminating a water molecule. Thousands of molecules join up, giving a macromolecule.