ISSN:
0959-8103
Schlagwort(e):
polymerization of 1,3-butadiene
;
MgCl2-supported CoBr2 catalysts
;
control of 1,2-content
;
triphenylphosphine
;
dimethoxydiphenylsilane
;
Chemistry
;
Polymer and Materials Science
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
,
Maschinenbau
,
Physik
Notizen:
MgCl2-supported CoBr2 catalysts were prepared from mixture of MgCl2 and CoBr2L2 (L = triphenylphosphine or pyridine) in toluene. Polymerization of 1,3-butadiene was conducted over the catalysts combined with ordinary alkylaluminums as cocatalyst. The CoBr2(PPh3)2/MgCl2 catalyst gave polybutadiene with approximately 80% of 1,2 units, whereas cis-1,4-poly-butadiene was obtained with the CoBr2(C5H5N)2/MgCl2 catalyst.Addition of triphenylphospine to the latter catalyst caused a marked increase in the content of 1,2 units. The content of 1,2 units could be thus controlled in the range from 0 to 80% by changing the amount of triphenylphosphine.On the other hand, the CoBr2(PPh3)2/MgCl2 catalyst with very low content of CoBr2(PPh3)2 hardly displayed any activity. Addition of dimethoxydiphenylsilane to the catalyst gave polybutadiene containing 90 % of 1,2 units with a fairly high activity.
Zusätzliches Material:
1 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/pi.1995.210360107
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