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.

The cationic polymerization of cyclopentadiene (CPD) initiated by different initiators (triphenylmethyl chloride, triphenylmethyl bromide, methyl triflate, and trifluoroacetic acid) onto silica particles yields polycyclopentadiene (PCPD)-silica composites in high yield beside small amounts of soluble polymers. The novel PCPD-silica particles are characterized by UVNIS reflectance spectra and IR spectra. The percentage of coating (PG) is determined by combustion analysis and depends on the reaction temperature and the technical procedure of the polymerization. The influence of the initiator used and initiator/monomer ratio on the PG of the silica particles are investigated, too. It can be shown that the total amount of coating strongly depends on the initiator used. In case of trifluoroacetic acid initiation, particle aggregation takes place if the carbon content of the PCPD particles exceeds 15% carbon weight due to crosslinking between the PCPD layers of the coated silica particles, as evidenced by electron scanning microscopy.

The cationic polymerization of cyclopentadiene (CPD) in the presence of silica gel particles is initiated by triphenylmethyl chloride, triphenylmethyl bromide, and methyl triflate in 1,2-dichloroethane. The suspension polymerization yields soluble colourless polycyclopentadiene (PCPD) and intensively blue coloured silica particles (PCPD' silica). The formation of the polymer structure on the silica surface in suspension is followed by transmission UVNIS spectroscopy and solution (lH and I3C) NMR spectroscopy. The structure of the novel solid materials (PCPD modified silica particles) is additionally investigated by DRIFT spectroscopy, solid-state I3C CP/MAS NMR spectroscopy and scanning electron microscopy (SEM).The blue colour of the PCPD' silica particles is caused by polyenylium sequences with five or six conjugated double bonds along the isomerized PCPD chains. The PCPD' structures are compared with similar ionic model compounds derived from retinol and retinal, respectively. The remaining of the PCPD layer including the conjugated sequences on the surface is attributed to the formation of covalent S i -0 -C bonds. Model reactions of the cationically active PCPD' silica particles with benzyltriethylammonium chloride and hexachloroantimonate, as well as charge transfer complex formation of the PCPD polymer layer with carbenium salts, (C6H5)3C+AsF; and C7HTBFi, are also investigated. A possible mechanism for the formation of crosslinked PCPD layers on the silica surface is suggested.