S. Komiya, A. Yamamoto, S. Ikeda
1975
Citations
0
Influential Citations
26
Citations
Journal
Bulletin of the Chemical Society of Japan
Abstract
Dihydridotetrakis(triphenyIphosphine)ruthenium(II) 1 initiates the polymerization of α-substituted olefins of high e-values such as acrylonitrile and forms unstable complexes with olefins of low e-values. Molecular weight of the polymer obtained by the polymerization of acrylonitrile with 1 was independent of polymerization time and increased linearly with the monomer concentration. The rate of polymerization was measured by a dilatometry and compared with the rate of decomposition of 1 in the presence of acrylonitrile followed by a spectroscopic method. The rate of decomposition of 1 was found to be equivalent to the rate of initiation of polymerization and can be expressed by the following equations: -\fracddt[Ru]=k[Ru], \frac1k=A+{B+C[PPh_3]}/[monomer] On the basis of the kinetic results and the independence of molecular weight of the polymer on time, a mechanism involving a slow initiation step followed by rapid propagation and termination steps is proposed.