Abstract
Summary: A kinetic study of the polymerization of a mixture of 1,3‐pentadiene isomers initiated by AlCl~3~ was carried out in pentane at −10 and 20 °C. A second apparent monomer order was found mainly at room temperature and was explained by a complexation of propagating active centers by the polymer, the true monomer order being first. This apparent order did not result from the presence of the two isomers in the monomer mixture. Kinetic simulations confirmed this interpretation and pointed out the fact that the interaction between the polymer and the active centers was stronger at −10 °C, thus limiting the polymer conversion at this temperature. The novelty of these findings lies in the fact that the inactive complexed centers can be activated by reaction with the monomer, providing active species when necessary. The existence of active centers even after a long reaction time at room temperature, and the reactivation of the complexed centers, was evidenced by incremental monomer addition and by the formation of sulfonium ions after quenching the polymerization by an excess of dimethyl sulfide. The latter were characterized by ^1^H NMR spectroscopy.
Complexation of propagating active centers by the polymer giving dormant species (C^+^/P), with following reactivation by a new monomer charge.
magnified imageComplexation of propagating active centers by the polymer giving dormant species (C^+^/P), with following reactivation by a new monomer charge.