Homo- and copolymers of isobutene are prepared by continuous cationic
polymerization of isobutene or mixtures of isobutene with ethylenically
unsaturated comonomers in the presence of an initiator system comprising:
i) a Lewis acid selected from covalent metal-halogen compounds and covalent
semimetal-halogen compounds and
ii) at least one aprotic organic compound I having at least one functional
group FG which forms a carbocation or a cationic complex with the Lewis
acid under polymerization conditions in an organic solvent inert with
respect to the Lewis acid, by a process in which the polymerization is
carried out in a tubular flow-through reactor which has a plurality of
curves having an alternating direction of curvature.
