LIVING POLYMERIZATION REACTORS .2. THEORETICAL AND EXPERIMENTAL TESTSON AN ALGORITHM WHICH PREDICTS MWDS FROM CSTRS WITH PERTURBED FEEDS

In Part 1 of this work (Gosden et al., 1996) a novel algorithm has bee n described for the fast calculation of complex molecular weight distr ibutions (MWD) produced in living anionic polymerisation conducted in periodically perturbed continuous stirred tank reactor (CSTR). Here it is shown by rigorous derivation that the new formula of Gosden el al gives the correct solution of the sets of differential equations which describe living polymerisation reactions in CSTR reactors where mixin g can be regarded as perfect. A numerical validation of the algorithm is also reported where computed solutions have been compared with the results obtained by traditional numerical integration methods and perf ect agreement has been found. Experiments are also reported which have been carried out with a computer controlled laboratory-scale polymeri sation reactor in an attempt to validate the simulation predictions. R esults are presented which show that, for a simple square-pulse input perturbation in monomer and initiator feed concentrations, there is go od agreement between theory and practice. In order to make realistic c omparisons between theory and the gel permeation chromatography data o btained with samples taken from the reactor, the simulated data has be en deliberately broadened with a Gaussian function in an attempt to mi mic reactor and any other broadening effects which might stem from the method of analysis. Some wider issues relating to polymerisation reac tor control using pulsed feeds and the wider application of the algori thm are briefly reviewed.