The epsilon-caprolactone bulk polymerisation, initiated by tetrapropoxy titanium, was investigated in a co-rotating twin screw extruder. On the basis of pressure measurements, the process dynamic modelling was achieved. The pressure drop at the exit die of the extruder was correlated to the rheological behavior of the melt polycaprolactone owing to equation which characterise the flow inside the die. The residence time distribution modelling was determined with an in-line Ultra-Violet fluorescence method. Thus, the combination of both modellings leads to the process dynamic modelling. This work constitutes the basis for an approach of the process regulation by the way of an internal model control. Simulation has given good results. However, the large response time to the control, relative to the process dynamic, constitutes effectiveness limiting factor for experimental control of the process.