Vinylformamide (VFA) is cationically polymerized in various solvents at 273 K and reaction temperature by the following initiators: iodine, bis(4‐methoxyphenyl)‐methyl chloride/silica, triphenylmethyl chloride/silica, and trimethylsilyl triflate. In every case defined oligomers with narrow molecular weight distribution are obtained in moderate yield (20–50%). Acid hydrolysis of the obtained oligomers yields well defined oligovinylamine products. The cationic initiation mechanism of VFA is discussed in terms of the HSAB‐concept

The cationic polymerization of electron rich monomers such as vinyl ethers, vinyl furane, and cyclopentadiene on silica surfaces can be initiated by aryl methyl halides. The reactions yield always soluble polymers (by heterogeneous catalysis) and novel polymer/silica hybrid materials. The link between polymer and solid is caused by covalent Si‐O‐C bonds, by network formation of the polymers during the chain growth, or by a combination of both of them. The analysis of the polymer structures on the surface by 1H MAS NMR spectroscopy in suspension and by solid state 13C CP MAS NMR spectroscopy is described. Proof of Si‐O‐C bonds via DRIFT spectroscopy and 13C CP MAS NMR spectroscopy is given. The most effective method of irreversibly linking the polymer to the silica surface is the network formation. Polyvinyl ethers are bound strongly to the surface, as can be shown by FTIR measurements, but the linkage is not stable due to the Si‐O‐C bonds' susceptibility to hydrolysis. Poly‐cyclopentadienes (PCPD) are linked to the surface by Si‐O‐C bonds, which show an extraordinary high resistance to acids and bases. Si‐O‐C bond formation of poly‐2‐vinyl furane could not yet be detected by 13C CP MAS NMR spectroscopy and DRIFT spectroscopy. In this case the high degree of coating derives from the bifunctionality of 2‐vinyl furane: it may undergo Friedel‐Crafts‐alkylation at the 5‐position of the furane ring as well as chain polymerization via the vinyl group at the 2‐position.

Addition of vinyl ethers to arylmethyl halides and silica at 0 and -78 °C results in the formation of polymers. The average molecular weight, the molecular weight distribution (MWD), and the head group functionality are strongly dependent on the structure of the arylmethyl halide and on the olefin/arylmethyl halide ratio. The heterogeneous induced polymerization depends not only on the temperature but also on the kind of silica used, e.g. Aerosil (Degussa) and Kieselgel 60 (KG 60) (Merck). We found that initiation with carbocations of the type ( 4) H, C6H5) with an electrophilicity in the range of -5 > pKR+ > -9 bearing a chloride counterion yields highly head group functionalized polymers. General mechanisms for the initiation and propagation step of the surface-mediated cationic vinyl ether polymerization considering the influence of the counterion and the initiating carbocation are discussed.

Poly(isobutyl vinyl ether) (PIBVE) with bis(4‐methoxyphenyl)methyl‐head‐group is transformed into a cationically active macro initiator by a hydride transfer reaction with silica surface coordinated triphenylmethylium as the hydride acceptor. The formation of the macrocation is investigated directly by UV/Vis spectroscopy on the surface of the silica particles and by GPC analysis of the surrounding solution. The hydride transfer reaction can be observed on the surface of the silica in a narrow temperature window between –5 and + 5°C. The use of the novel silica supported macrocation for a block copolymer synthesis with N‐vinylcarbazol (NVC) is demonstrated.