T. Sarbu et Ej. Beekman, Homopolymerization and copolymerization of cyclohexene oxide with carbon dioxide using zinc and aluminum catalysts, MACROMOLEC, 32(21), 1999, pp. 6904-6912
Homopolymerization of cyclohexene oxide and copolymerization of cyclohexene
oxide and carbon dioxide using zinc and aluminum catalysts having the same
type of substitution were studied. The aluminum derivatives are more activ
e, in both homopolymerization and copolymerization of cyclohexene oxide and
carbon dioxide. From Al-27 NMR spectra it was observed that aluminum catal
ysts consist of both penta- and hexacoordinated species but after reaction
with monomer predominantly become pentacoordinated. During initiation the e
quilibrium between five and six hypercoordinated species is shifted toward
lower coordination. The nature of the catalysts and their symmetry influenc
e the yield in the copolymerization of CHO and CO2 and the amount of carbon
dioxide inserted. The yield obtained with aluminum derivatives luring the
copolymerization of CHO and CO2 ranged between 41.2 and 93.6% (149.85-340.4
g of polymer/g of metal).