In recent years progress has been made in mathematical modelling of complicated chemical systems. Simulation of reactions with computational techniques offers an excellent method for testing the extent to which a reaction mechanism is indeed understood. After considering the principles of modelling and its advantages in general we present a new type of modelling of polymerizations and its advantages in particular. This method typically involves time‐stepwise integration of kinetic equations and works at a level in between macroscopic (= conventional kinetics) and microscopic (= molecular statistics). At this “semi‐microscopic” level reactants are discriminated not only by the functional groups but also by the chain lengths. Since this method additionally provides information on molecular mass distribution, better facilities to fit experimental data and, therefore, higher confidence in the accuracy of the model are achieved. With regard to cationic polymerization of alkenes there still is uncertainty of some mechanistic details. Showing the latest developments of our new method specially developed for polymerizations we will discuss our first results. Our objective is to apply the new method for kinetic investigations and to contribute new information on this field.

SUMMARYAromatic and aliphatic hydrocarbons containing isopropyl chloride end groups in combination with boron trichloride are effective initiator systems for the cationic polymerization of methyl propene. The mathematical modelling of the proposed reaction mechanism leads to rate constants for initiation, propagation and termination which allows a good fit with experimental results. Recycling experiments have clearly shown that it is possible to reuse the coinitiator boron trichloride and the solvent dichloromethane without effecting the quality of the products.Vortrag anlaslich der Tagung der Fachgruppe "Makromolekulare Chemie" der Gesellschaft Deutscher Chemiker uber "Neue Polymere -

SUMMARY:Using a simple, instructive model of living polymerizations, we develop an economic technique for solving a complete set of kinetic equations for active polymers P,* with chain length n. The method consists of two steps: (i) solution of the global kinetic equations for the global species P* which comprises all individual polymers P,* together with monomer M and other non-polymeric species, followed by (ii) iterative solution of the original kinetic equations, successively for the individual polymers PT, P; , Pf, . . . , P,*. The method is applied successfully to a rather complex, realistic model of cationic polymerizations. In general, our iterative scheme serves to reduce numerical storage requirements, in comparison with traditional direct integrations for all individual kinetic equations. Therefore it may allow simulations of very demanding polymerizations, including very high degrees of polymerization, which cannot be evaluated by traditional techniques.