Polymerization of acenaphthylene initiated by iodine

The kinetics of iodine initiated polymerization of acenaphthylene has been followed dilatometrically at 0, 20 and 30°C. in (CH2Cl)2 using a semi‐open technique. Experiments in vacuum dilatometers fitted with electrodes have been also carried out in order to follow the conducativity at the same time as the conversion. The general features of this polymerization are analogous with those of iodine initiated polymerization of styrene (S‐shaped time‐conversion curves, high reaction order with respect to the iodine concentration, co‐catalysis by hydrogen iodide). The slowness of the reaction and the low conductivity in the steady‐state suggest that it is a pseudocationic reaction.