CATIONIC COATING POLYMERIZATION OF CYCLOPENTADIENE ONTO SILICA PARTICLES

The cationic polymerization of cyclopentadiene (CPD) initiated by diff erent initiators (triphenylmethyl chloride, triphenylmethyl bromide, m ethyl triflate, and trifluoroacetic acid) onto silica particles yields polycyclopentadiene (PCPD)-silica composites in high yield beside sma ll amounts of soluble polymers. The novel PCPD-silica particles are ch aracterized by UV/VIS reflectance spectra and IR spectra. The percenta ge of coating (PG) is determined by combustion analysis and depends on the reaction temperature and the technical procedure of the polymeriz ation. The influence of the initiator used and initiator/monomer ratio on the PG of the silica particles are investigated, too. It can be sh own that the total amount of coating strongly depends on the initiator used. In case of trifluoroacetic acid initiation, particle aggregatio n takes place if the carbon content of the PCPD particles exceeds 15% carbon weight due to crosslinking between the PCPD layers of the coate d silica particles, as evidenced by electron scanning microscopy.