4.1 POLYMER
Natural polymers are polymers that are naturally available and can be obtained from our surroundings.
Examples of natural polymers are starch, protein and cotton
A polymer is a long chain molecule that is made from a combination of many repeating basic unit
Synthetic polymers, on the other hand, are man-made through chemical reactions in laboratories or factories.
Nylon, polyethene, polystyrene and polyvinyl chloride (PVC) are examples of synthetic polymers that are manufactured in the industrial sector
Types of Polymers
• Thermoplastic polymers are polymers that can be repeatedly remoulded upon heating and can be recycled.
• When heated, the thermoplastic polymers melt and solidify when they are cooled.
• Example: polyethene, polyvinyl chloride (PVC), nylon.
Thermoplastic polymers
-Thermosetting polymers cannot be remoulded after heating.
-Thermosetting polymers normally disintegrate or burn upon heating and cannot be recycled
-Example: melamine, bakelite.
Thermoplastic polymers
Elastomer polymers can be stretched and can return to their original shape when released.
• Possess high elasticity properties.
• Example: polyurethane, styrene-butadiene rubber (SBR).
Thermosetting polymers
