Preparation and Properties of Polydienes

1973 ◽  
Vol 46 (4) ◽  
pp. 1055-1067 ◽  
Author(s):  
W. M. Saltman ◽  
L. J. Kuzma
Keyword(s):  
Molecular Weight ◽  
Nickel Catalyst ◽  
Marked Effect ◽  
Polymerization Rate ◽  
Cobalt Catalysts ◽  
Trans Content ◽  
Polymer Molecular Weight ◽  
Initiation Step ◽  
Butadiene Polymerization

Abstract In summary there are presented some new data on the initiation step for poly-(butadiene) polymerization with the AlEt3-Ni-BF3 catalyst which describe what appears to be a “settling down” period of newborn chains at the π-bonded nickel catalyst site. This leads to a segment of higher trans content at the end of each high cis-1,4-poly(butadiene) chain. Comparisons between nickel and cobalt catalysts seem to point up their differences rather than their similarities. We have described the role of water in effectively changing the identity of the aluminum alkyl which in turn has a marked effect on the polymerization rate, on the polymer molecular weight and the extent of crosslinking.

Polymerization of Butadiene with Alkylaluminum and Cobalt Chloride

1962 ◽  
Vol 35 (4) ◽  
pp. 1066-1082 ◽  
Author(s):  
Morris Gippin
Keyword(s):  
Molecular Weight ◽  
Cobalt Chloride ◽  
Polymer Molecular Weight ◽  
Cobaltous Chloride ◽  
First Order ◽  
Pyridine Complex ◽  
Fixed Concentration ◽  
Rate Of Polymerization ◽  
Butadiene Polymerization ◽  
Derivatives Of

Abstract The diethylaluminum chloride combination with cobaltous chloride or cobaltous chloride pyridinates requires water in a certain mole ratio to the diethylaluminum chloride to activate them as catalysts for butadiene polymerization at 5° C to 98% cis-1,4 structure. The cobalt-pyridine complex is the preferred component because of its ability to function in trace amounts. Several organic derivatives of water failed as substitutes. However, aluminum trichloride is effective as a substitute for water on an equimolar basis. The cis-1,4 content in the polymer decreases at higher polymerization temperatures. The higher pyridinates of cobaltous chloride tend to reduce the polymer molecular weight within narrow limits. The preferred solvent is benzene, in which the concentration of the monomer is a factor in both microstructure and polymer molecular weight. Certain mixtures of benzene and hexane provide another means of controlling molecular weight. The rate of polymerization is linear with respect to time in the initial stages, and is a first-order reaction with respect to monomer at a fixed concentration of catalyst.

Determining the Role of Polymer Molecular Weight for High-Performance All-Polymer Solar Cells: Its Effect on Polymer Aggregation and Phase Separation

2015 ◽  
Vol 137 (6) ◽  
pp. 2359-2365 ◽  
Author(s):  
Hyunbum Kang ◽  
Mohammad Afsar Uddin ◽  
Changyeon Lee ◽  
Ki-Hyun Kim ◽  
Thanh Luan Nguyen ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Solar Cells ◽  
Phase Separation ◽  
High Performance ◽  
Polymer Solar Cells ◽  
Polymer Molecular Weight

scholarly journals Reinforcement of macroscopic carbon nanotube structures by polymer intercalation: The role of polymer molecular weight and chain conformation

2005 ◽  
Vol 72 (24) ◽  
Author(s):  
C. J. Frizzell ◽  
M. in het Panhuis ◽  
D. H. Coutinho ◽  
K. J. Balkus ◽  
A. I. Minett ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Carbon Nanotube ◽  
Chain Conformation ◽  
Polymer Molecular Weight
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