Polymerisation process

Ionic polymerisation cascade process for the polymerisation of a liquid monomer(s) containing reaction mixture in a polymerisation system comprising a first homogenising prepolymerisation unit (“HPPU”) and a second polymerisation unit in series wherein the polymerisation reaction starts in the HPPU and continues in the second polymerisation unit consisting of a polymerisation loop, a coolant loop and a heat exchanger reactor system (“HERS”) which is shared amongst the polymerisation loop and the coolant loop, characterised in that

• the HERS has a ratio of surface area to reaction mixture volume (“S/V” expressed in m2/m3) higher than 10 and lower than 450, and
• the HPPU has a ratio of surface area to reaction mixture volume (“S/V” expressed in m2/m3) higher than 600, and
• the ratio between the residence time of the reaction mixture in the first homogenising prepolymerisation unit and the residence time of the reaction mixture in the second polymerisation unit is comprised between 0.01% and 5%.