Page 15 - 1202 Question Bank Chemistry Form 5 KSSM

4
Chapter Polymer

NOTES

4.1 Polymers (c) After it has set, it cannot alter its shape when
heated and cooled again
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1. A polymer is a long chain molecule that is made from (d) Stronger than thermoplastic
a combination of many repeating basic units known (e) Opaque
as monomer. (f) Can only be moulded once and cannot be
2. Polymerisation is the monomer combination reaction recycled
to produce big, long chained molecules known as Example:
polymers. • Bakelite: Plug, electrical switches, cooking utensil
holder
Covalent bond
Polymerisation • Melamine: Dinnerware, countertops
• Epoxy resin adhesives: Adhesives for metals, glass,
Polymer wood, and battery casing
Monomers 7. Elastomer:
(a) Has few cross linkages.
3. Polymers can be divided into natural polymers and (b) Rubber-like properties, it can be thermoplastic
synthetic polymers.
or thermosetting.
Natural polymers Synthetic polymers (c) More elastic than thermoplastic.
(d) Can be stretched and return to its original shape
Monomer Polymer Monomer Polymer
Example: Natural and synthetic rubber
Glucose Starch Propene Polypropene 8. There are two types of polymerisation: Addition
Isoprene Natural Styrene Polystyrene polymerisation and condensation polymerisation.
rubber 9. During addition polymerisation, alkene monomers
that contain double bonds between carbon atoms,
Amino Protein Ethene Polyethene C=C are added to one another to form polymers
acids
under a high temperature condition.
Example:
4. Based on the intermolecular forces, polymers are
classified into thermoplastic, thermosetting and H H H H
elastomer.
n C C C C
5. Thermoplastic:
(a) Has long chain, no cross linkages. H H H H n
(b) Produced from addition polymerisation. Ethene Polyethene
(c) Can change shape when heated or cooled.
(d) Not as strong as thermosetting. 10. In condensation polymerisation, monomers without
(e) Colourless and transparent. double bonds are combined to form long polymer
(f) Can be moulded repeatedly and can be recycled. chain and by-product.
Example: Example:
• Polyethene: Plastic bag, bottles (a) Formation of nylon-6,10 through condensation
• Polypropylene: Chairs, feeding bottles polymerisation.
• Polystyrene: Food packaging
O O
• Polyvinyl chloride (PVC): Electric wire and cable
H N (CH ) NH + Cl C (CH ) C Cl
insulators, clothes hanger, water pipes 2 2 6 2 2 8
• Perspex: Car windscreen, aircraft windows 1,6-hexanediamine Decanedioyl dichloride
6. Thermosetting:
(a) Has many cross linkages, forms three
dimensional network
(b) Produced from condensation polymerisation
O O
(HN (CH ) (NH C (CH ) C ) + 2HCl
2 6 2 8 n
Nylon-6,10

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