Solution polymerisation plant and process

Heating is often by steam or pressurised hot water, but other methods such as thermal fluid or induction heating are also frequently employed. It is normal to zone the heating coils to protect the exposed areas of the reactor walls from localised overheating. 

The reactor is normally equipped for external cooling via coils or jacket, and also with internal cooling coils for quenching the reaction in an emergency, and to assist in controlling the temperature against the reaction exotherm. 

Agitation of the reaction mass is usually by means of a multi-bladed stirrer, preferably driven via a variable speed gear box. 

The vessel is equipped with a reflux condenser, water separator (for reactions involving water removal such as methylolation of acrylamide) and a vacuum receiver. The reactor top is normally fitted with an illuminated sight glass and entry ways for monomer, solvent and initiator. 

Due to the chain transfer effect of some solvents where higher molecular weight polymers are required, the polymerisation is carried out at high solids content (80-85%) and diluted with further solvent when the polymerisation is completed. 

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