Homogeneous and heterogeneous polymerisation.

Polymerisation process

• The polymerisation process is classified into homogeneous and heterogeneous polymerisation.
• In homogeneous polymerisation as name suggest the reactants i.e monomer, initiator, solvents and polymer obtained are miscible and compatible.
• In heterogeneous polymerisation the monomers, catalyst and polymers obtained are immiscible.
• Homogeneous polymerisation comprises of bulk/mass polymerisation and solution polymerisation.
• Heterogeneous polymerisation comprises of bulk, solution, suspension, emulsion, gas phase, precipitation and interfacial polymerisation.

Homogeneous polymerisation

1) Bulk/mass polymerisation

• In case of homogeneous bulk polymerisation the monomer is miscible in polymer obtained.
• Here the radical initiator is dissolve in pure liquid monomer in the absence of any solvent.
• The reaction is initiated by exposing the mixture to light or by heating .
• As reaction proceeds solution mixture becomes more viscous and a polymer is obtained.
• This method is suitable for producing pure polymers.
• This method is exothermic.
• Styrene is produce by this method.

2) Solution polymerisation

• In Solution polymerisation the monomer, catalyst and polymer obtained are soluble in a solvent.
• In this method the monomer and catalyst are dissolve in a solvent to form a solution which reacts without any heat or cooling or any special handling to give polymers.
• High density polyethylene is prepared from this method.

Ring opening polymerisation.