Table of Contents
IGCSE Coordinated Science: Synthetic Polymers
Synthetic Polymers
-
Describe the formation of poly(ethene) as an example of addition polymerisation of monomer units.
A polymer is a substance that contains large molecules formed by many small molecules added together.
Let’s take ethene as an example
A polymer that is made from ethene is called “Poly-ethene”. Poly- basically just means many. We often call this reaction Polymerisation, or polymerization if you’re American.
In a polymerization reaction, what essentially happens is that thousands or smaller molecules join to form a macromolecule. We call these small molecules monomers.
- Draw the structure of poly(ethene).
What’s so cool about it is that it literally repeats forever.
Condensation polymer
Double bonds break, which allows monomers molecules to ultimately join together. However, in condensation polymer, no double bonds break. Alternatively:
- Two different monomers join.
- The monomers join at their function groups by eliminating small molecules.
Go on google and find the structure of Diaminohexane and Hexan-1,6 Dioyl Chloride.
Now, lets call them A and B respectively.
A has an NH2 group at each end. B has a COCl group at each end. Only these parts, called functional groups take part in the reaction.
- The nitrogen atom at one end of “A” has joined to the carbon atom at one end of B, by eliminating a molecule of hydrogen chloride.
- This continues at the other ends of A and B
