Activity 3.2 - Polymerization – polycondensation

• To show one way of polymer preparation.
• Understanding of term polycondensation as a method of polymer preparation.

• solution of adipoylchloride in hexane,
• aqueous solution of hexane-1,6-diamine,
• beaker,
• glass bar,
• tweezers

Procedure:

1. Pour solution of adipoylchloride in hexane into narrow higher beaker.
2. Pour carefully aqueous solution of hexane 1,6 diamine into the beaker with solution of adipoylchloride under the layer of hexane.
3. Thin layer of synthetic polymer is formed at interface of both of the layers.
4. Take the polymer by tweezers and pull it out above the surface of the solutions and coil it on the glass bar.

Discussion:

Polymers can be prepared by three various polyreactions. They are polymerization, polycondensation and polyadition. Polymerization is addition of monomer on double bond of monomer (by a macroion or by a radical). During polycondensation, the polymer from typically bifunctional monomers is formed and some small molecules like water or carbon dioxide are released. Polyamides (Nylon, Silon) are typically prepared by polycondensation. They are mosly prepared by the reaction of bifunctional carboxylic acid (or they chlorides) and diamines, when water or hydrochloric acid are released.

• What are mechanical properties of formed polymer? It is hard and solid fiber.

• Which group of polymers the prepared polymer belongs to? Polyamides.