Control of bulk epsilon-caprolactone polymerization in a twin screw extruder

The bulk polymerisation of epsilon-caprolactone initiated by tetrapropoxy t itanium was investigated in a co-rotating twin screw extruder. The process dynamic modelling, based on pressure measurements, was achieved via a combi nation of rheological modelling coupled with residence time distribution mo delling. The former was deduced from equations which characterise the flow inside the die and the rheological behaviour of the melt polymer. The latte r was determined with an in-line Ultra-Violet fluorescence method. An appro ach for the process regulation by the way of internal model control has giv en good results in simulation. However, the large response time to the cont rol, relative to the process dynamic, constitutes a limiting factor for exp erimental control of the process.