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Formation and degradation of 1,4‐polybutadiene via metathesis: new results concerning cyclic oligomers
Author(s) -
ThornCsányi Emma,
Hammer Jens,
Pflug Kai P.,
Zilles J. Ulrich
Publication year - 1995
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.1995.021960407
Subject(s) - romp , metathesis , ring opening metathesis polymerisation , acyclic diene metathesis , polybutadiene , polymer chemistry , chemistry , intramolecular force , polymerization , salt metathesis reaction , carbene , cyclobutene , ring opening polymerization , photochemistry , ring (chemistry) , catalysis , organic chemistry , polymer , copolymer
The ring‐opening metathesis polymerization (ROMP) of cyclic oligomers of butadiene ( c,c ‐1,5‐cyclooctadiene — COD —, t,t,t ‐1,5,9‐cyclododecatriene — CDT —), the acyclic diene metathesis (ADMET) of 1,5‐hexadiene and the intramolecular metathesis degradation of 1,4‐polybutadiene (1,4‐BR) were studied using stable tungsten and molybdenum carbene complexes as well as conventional metathesis catalysts. The determination of cyclic oligomers up to rings containing eight butadiene units shows, compared to the literature, different results regarding the distribution, concentration and cis/trans ratio. Kinetic studies of the ROMP of COD and the intramolecular metathesis of 1,4‐BR allow to explain the discrepancy. The ROMP product spectrum for the cyclobutene system known and accepted until now in the literature as ring‐chain equilibrium is controlled kinetically and far apart from thermodynamic equilibrium according to our results.