Our investigations target the effect of solvents, temperature, initiators, Lewis-acid coinitiators and nucleophilic additives on the polymerization. The monomers studied are isobutylene, styrene and derivatives thereof. Our major results include:

A living carbocation-ended polyisobutylene chain complexed with a transition metal gegenion

- Performing the quasiliving carbocationic polymerization of isobutylene in the presence of chelating compounds, a new class of nucleophilic additives, resulting in polyisobutlyene oligomers with ultra narrow molecular weight distribution (see figure to left).

- Revealing the relationship between the molecular structure of the nucleophilic additive and its effect on the carbocationic polymerization of isobutylene.

- Through the use of several solvents in the polymerization of isobutylene a strong solvent effect was demonstrated, influenced by the chemical structure of the solvent as well as its polarity.

- With benzotrifluoride as reaction medium it is possible to synthesize well-defined polyisobutylenes at elevated temperatures (-20...0°C).

Gel permeation chromatograms for the demonstration of the effect of a N-containing chelating nucleophile (TMEDA, yellow line) on polydispersity

For comparison, the case of using a conventional nucleophile (DMPy, blue line) and that of additive-free polymerization (white line) are also presented.

- Analysis of slow initiation in the case of a new initiator in the carbocationic polymerization of isobutylene.

- New functionalizing reactions in isobutlyene and styrene polymerizations, modification of the functional groups.

- Synthesis of well-defined poly(isobutylene-b-styrene) block copolymers by carbocationic polyme-rization on the basis of kinetic investigations.