Abstract: 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.

Abstract: A curved tubular flow reactor designed for carrying out chemical reactions continuously, for preparing mixtures and as a liquid-phase heat exchanger comprises a plurality of successive bends having alternating directions of curvature.

Abstract: Absorber elements are described of at least one composite material having absorbent elements on a support, in which a plurality of elements of a superabsorbent foam are arranged on at least one support in a grid pattern at distances such that the elements in the swollen state touch at their peripheries.

Abstract: Water-absorbing foamlike crosslinked polymers which are obtainable by (I) foaming a polymerizable aqueous mixture which consists of (a) monoethylenically unsaturated monomers containing acid groups, which are at least 50 mol % neutralized, (b) with or without other monoethylenically unsaturated monomers, (c) crosslinker, (d) initiators, (e) from 0.1 to 20% by weight of at least one surfactant, (f) with or without one or more solubilizers and (g) with or without thickeners, foam stabilizers, polymerization regulators, fillers and/or cell nucleating agents, the foaming being performed by dispersing fine bubbles of a gas inert to free radicals, and (II) polymerizing the foamed mixture with formation of a foamed hydrogel, with or without adjusting the water content of the foamed polymer to from 1 to 60% by weight, processes for their preparation and their use in sanitary articles which are used for absorbing body fluids and in dressing materials for covering wounds are described.