Polymerisation

Polymerisation

1. Addition

   • Free radical
     • Initiators
       • Peroxides and Hydroperoxides
       • Photoinitiators
         • Advantages:
           • The reaction is eassentially indenpendent of temperature
           • Polymerisation may be conducted at very low temperatures
           • Better control of the polymerisation reaction
           • The reaction can be stopped simply by removing the light source
       • Electrochemical polymerisaion initiation
         • very often used in water based polymerisation (i.e. monomer = H2O)
       • Thermal polymerisation initiation
     • Retarders
     • Inhibitors
     • Thermodynamics
       • "Ceiling" temperature ( T ceiling)
     • Chain growth and regiochemistry
       • Head favoured (due to resonance stabilisation)
     • Free radical polymerisation in solutions result in predominantly ATACTIC polymers
     • Chain branching
     • Polymerisation Techniques
       • Bulk
       • Suspension
       • Solution
       • Emulsion
   • Cation
   • Anion

2. Step-growth

   • Poly condensation

3. Insertion

   • Metathesis
   • Zieglar-Natta