STUDY OF MECHANISM OF CIS-1,4 POLYMERIZATION CATALYZED WITH HETEROGENEOUS AND HOMOGENEOUS CATALYSTS FROM THE STANDPOINT OF MOLECULAR WEIGHT DISTRIBUTION
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STUDY OF MECHANISM OF CIS-1,4 POLYMERIZATION CATALYZED WITH HETEROGENEOUS AND HOMOGENEOUS CATALYSTS FROM THE STANDPOINT OF MOLECULAR WEIGHT DISTRIBUTION
CIESC JournalIssue 2, (1966)
作者机构:
中国科学院应用化学硏究所,中国科学院应用化学硏究所
作者简介:
基金信息:
DOI:
CLC:
Online First:25 June 1966,
Published:25 June 1966
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谢洪泉, 汪月生. STUDY OF MECHANISM OF CIS-1,4 POLYMERIZATION CATALYZED WITH HETEROGENEOUS AND HOMOGENEOUS CATALYSTS FROM THE STANDPOINT OF MOLECULAR WEIGHT DISTRIBUTION[J]. CIESC Journal, 1966, (2).
DOI:
谢洪泉, 汪月生. STUDY OF MECHANISM OF CIS-1,4 POLYMERIZATION CATALYZED WITH HETEROGENEOUS AND HOMOGENEOUS CATALYSTS FROM THE STANDPOINT OF MOLECULAR WEIGHT DISTRIBUTION[J]. CIESC Journal, 1966, (2).DOI:
STUDY OF MECHANISM OF CIS-1,4 POLYMERIZATION CATALYZED WITH HETEROGENEOUS AND HOMOGENEOUS CATALYSTS FROM THE STANDPOINT OF MOLECULAR WEIGHT DISTRIBUTION
4 polybutadiene obtained by polymerization with homogeneous Ziegler catalyst (Et2AlCl-CoCl2-4C5H5N) as well as heterogeneous Ziegler catalyst (i-Bu3Al-Til4) has been determined by means of fractional precipitation. The results show that the molecular weight distribution of both types of polybutadiene is not broad. With regard to the homogeneous catalytic system
the molecular weight distribution becomes narrower when the temperature of polymerization is increased
the monomer concentration lowered
the chain transfer agent added and the cobalt concentration decreased or the Al/Co ratio increased. As to the heterogeneous catalytic system
the homogeneity of molecular weight distribution increases with the lowering of the polymerization temperature and the decreasing of the Al/Ti ratio. But the monomer concentration and aging of catalyst give no evident effect. Molecular weight distribution obtained with heterogeneous catalytic system is narrower than that obtained with homogeneous catalytic system. The peak of differential distribution curve of the former lies on higher molecular weight side
while that of the latter on lower molecular weight side. This is probably due to the fact that the chain terminating rate in the heterogeneous catalytic system depends upon chain length
while that in the homogeneous catalytic system is independent.