TACTICITY DISTRIBUTION AND SIMULATION

In many homopolymers the tacticity may be compositionally or sequentially heterogeneous. A computer simulation approach has been developed to simulate tacticity sequence and tacticity distribution for polymers made under a variety of conditions. Included in the simulation are the effects of molecular weight, consecutive and concurrent propagation models, and multiple catalyst/initiator states. In addition, heterogeneity brought about by the fluctuations in the reaction process conditions can also be incorporated. The effect of sequential heterogeneity can be separately visualized through the use of sequence index. Simulations have been made of the tacticity of poly(methyl methacrylate), poly(isopropenylpyridine), and polypropylene. In general, compositional heterogeneity has a large effect on the composition distribution curve but a lesser effect on NMR tacticity.