Polymerisation

Polymers are formed by reacting single organic molecules together at high pressure, often in the presence of a catalyst.

In these circumstances the molecules join together into much larger molecules with polymeric properties. These properties, so critical to subsequent processing, are often determined by the “length” of the polymer chains formed.

The lengths of the chains are a consequence of the conditions in the reactors and the effectiveness of the mixing.

The challenge has always been to measure the polymer properties as they are formed and the conditions, particularly the degree of mixing, in the reactors. This is made particularly difficult by the very high pressure conditions involved in most polymerisation reactors.

Process tomography sensors are extremely robust. 

High temperature ceramic sensor for tracking nylon polymerisation

Two sensor strategies have been successfully deployed for investigating such challenging reaction conditions:

• ceramic sensors have been developed to withstand high temperatures and pressures to characterise the polymerisation of nylon.  As nylon polymerisation is essentially a condensation reaction, with water being driven off, changes in conductivity can show the reaction's progress.  This can help improve product quality through improving reaction consistency through the reactor.
• high temperature polymers have also been deployed to investigate reactions at moderately high temperatures and high temperatures

Both ECT and ERT measurements are important for monitoring polymerisation.  This means that depending on the reaction conditions, either the m3000 or p2+ can be used.

Key benefits include:

• determination of concentration conditions within process volume

• characterise homogeneity to improve process consistency

• identification of end point of polymerisation