A Cyclobutane Derivative from Chloroprene Dimerization

KINETIC studies of the thermal polymerization of chloroprene indicate an unusual mechanism which involves formation of polymer from dimers and not from the chloroprene monomer 1,2 . The polymerization is initiated by traces of impurity in the monomer, and over a considerable range the observed rate and activation energy of polymer formation are identical with those for dimerization, indicating that the initial dimerization is the step which controls the rate in the consecutive reactions leading to polymer 3 . The characterization of the dimers and studies of the dimerization process are clearly prerequisites to understanding the mechanism of the polymerization. This communication is concerned with the initial problem of dimer separation and characterization.