In:
Journal of Polymer Science: Polymer Chemistry Edition, Wiley, Vol. 21, No. 7 ( 1983-07), p. 1951-1972
Abstract:
Butadiene is polymerized by cobalt compound–organoaluminum–CS 2 catalysts to give highly crystalline syndiotactic 1,2‐polybutadiene ( s ‐PB) having melting point up to 216°C. An aluminum‐free catalyst, Co(C 4 H 6 )(C 8 H 13 )‐CS 2 , is also effective. Syndiotactic polymerization with Co(C 4 H 6 )(C 8 H 13 )‐CS 2 is not interrupted by the addition of protic substances such as water and alcohol, but is influenced by donor or acceptor substances. The donor molecule, e.g., dimethylsulfoxide or dimethylformamide, decreases the stereoregularity, i.e., syndiotacticity and 1,2 content. An acceptor molecule of organoaluminum with appropriate acidity such as AlEt 3 ‐AlEt 2 Cl or tetraethylaluminoxane increases the molecular weight, stereoregularity, and yield of the polymer. In the presence of CS 2 a mixture of cis ‐PB and s ‐PB was obtained by using Co(octoate) 2 ‐AlEt 2 Cl‐H 2 O, with molar ratio H 2 O/Co less than unity. In the case of H 2 O/Co 〉 1, only cis ‐PB was obtained. By the addition of donor substances such as ester, ether, nitrile, and AlEt 3 , s ‐PB was obtained even when H 2 O/Co 〉 1. The amount and ratio of cis ‐PB and s ‐PB are dependent upon the nature and amount of the additives.
Type of Medium:
Online Resource
ISSN:
0360-6376
,
1542-9369
DOI:
10.1002/pol.17.v21:7
DOI:
10.1002/pol.1983.170210707
Language:
English
Publisher:
Wiley
Publication Date:
1983
detail.hit.zdb_id:
3004641-5
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