Polycondensation Kinetics of LA

Furthermore, polycondensation of LA with and widiout catalyst under closed and open conditions at different temperatures has been studied [28]. The experimental results are used to estimate the polymerization rate constant and the equilibrium constant. Accoimting for the actual rate of water removal, the model encompasses all possible situations and, in particular, the two limiting cases of complete water removal (ideal irreversible polycondensation) and no water removal (ideal reversible polycondensation). 

The mathematical model developed widi the assumption of a simple kinetic scheme and estimated kinetic parameters is instrumental to understand and to predict effects of different operating conditions on the polymer properties. Though the model results differ from the experimental results in terms of the polymer MWDs measured by GPC, the model predicted average polymer properties are in fairly good agreement with the experimental values. To improve the model predictions a better understanding of possible side reactions is most likely needed. Finally, in contrast to earlier literature results [29], no dependence of the pol)mier properties on the reactor pressure and/or pressure reduction rate is found through both the model simulations and experiments. 

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