Extended Two-Step Method for Molecular Weight Control in a Batch Polymerization Reactor

2001 ◽  
Vol 40 (18) ◽  
pp. 3929-3935
Author(s):  
Hyung-Jun Rho ◽  
Hyun-Ku Rhee
Keyword(s):  
Molecular Weight ◽  
Weight Control ◽  
Step Method ◽  
Molecular Weight Control ◽  
Polymerization Reactor

Enzyme-mediated radical initiation of acrylamide polymerization: main characteristics of molecular weight control

Polymer ◽  
2001 ◽  
Vol 42 (13) ◽  
pp. 5515-5521 ◽  
Author(s):  
Alain Durand ◽  
Thierry Lalot ◽  
Maryvonne Brigodiot ◽  
Ernest Maréchal
Keyword(s):  
Molecular Weight ◽  
Weight Control ◽  
Radical Initiation ◽  
Molecular Weight Control ◽  
Acrylamide Polymerization

Thermal Reorganization and Molecular Weight Control of Dynamic Covalent Polymers Containing Alkoxyamines in Their Main Chains

2007 ◽  
Vol 40 (5) ◽  
pp. 1429-1434 ◽  
Author(s):  
Hideyuki Otsuka ◽  
Koichiro Aotani ◽  
Yuji Higaki ◽  
Yoshifumi Amamoto ◽  
Atsushi Takahara
Keyword(s):  
Molecular Weight ◽  
Weight Control ◽  
Molecular Weight Control

New Alfin Rubbers

1970 ◽  
Vol 43 (2) ◽  
pp. 333-355 ◽  
Author(s):  
R. G. Newberg ◽  
H. Greenberg ◽  
T. Sato
Keyword(s):  
Molecular Weight ◽  
Laboratory Testing ◽  
Weight Control ◽  
Straight Chain ◽  
Cyclic Hydrocarbons ◽  
Molecular Weight Control ◽  
Heat Build Up ◽  
Polymerization Method ◽  
Butadiene Styrene

Abstract Molecular weight control for alfin catalyzed 1,3-diene polymers by 1,4-diene straight chain or cyclic hydrocarbons (and their derivatives) has been demonstrated. The microstructure of these moderated polymers is identical to the polymers obtained without molecular weight control. From the wide series of copolymers preparable with this improved polymerization method four were chosen for their evaluation after laboratory testing for processability, physicals, and economics. Copolymers of butadiene—isoprene (90/10 and 97/3) and butadiene—styrene (85/15 and 95/5) virgin or oil extended have been shown to be economically attractive and to give superior wear, traction, and adequate heat build up.

Kinetics and Molecular Weight Control of the Polymerization of Acrylamide via RAFT†

2004 ◽  
Vol 37 (24) ◽  
pp. 8941-8950 ◽  
Author(s):  
David B. Thomas ◽  
Anthony J. Convertine ◽  
Leslie J. Myrick ◽  
Charles W. Scales ◽  
Adam E. Smith ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Weight Control ◽  
Molecular Weight Control

Simultaneous Control of 1,4-cis Selectivity and Molecular Weight of Polymer in Polymerization of Butadiene with Co(acac)3/MAO Catalyst

2005 ◽  
Vol 78 (1) ◽  
pp. 143-154 ◽  
Author(s):  
Kiyoshi Endo ◽  
Naoyoshi Hatakeyama
Keyword(s):  
Molecular Weight ◽  
Reaction Time ◽  
Active Site ◽  
Weight Control ◽  
Catalyst Preparation ◽  
Polymerization Rate ◽  
Polymerization Time ◽  
Molecular Weights ◽  
Molecular Weight Control ◽  
Simultaneous Control

Abstract Simultaneous control of 1,4-cis selective polymerization and molecular weight of polymer in the polymerization of butadiene (BD) with Co(acac)3/MAO catalyst was investigated. The polymerization of BD with the Co(acac)3/MAO catalyst strongly depended on catalyst preparation, and the polymerization rate of BD with Co(acac)3 activated by MAO in the presence of BD was faster than that with previous reported results that the Co(acac)3 activated by MAO in the absence of BD. From a kinetic study, linear relation between ln[BD]0/[BD]t and polymerization time and no induction period for the polymerization were observed in the polymerization of BD with Co(acac)3 activated by MAO in the presence of BD. This indicates that the active site for the polymerization kept constant throughout polymerization. The molecular weights of the polymers increased linearly with polymer yields, and the line passed through the original point. The Mw/Mn of the polymers kept constant during reaction time. The polymerization of BD performed at 0 °C in the Co(acac)3/MAO catalyst gave high molecular weight 1,4-cis poly(BD) (1,4-cis content > 95) and narrow polydispersity (Mw/Mn=1.36). On the basis of these results, it is clear that simultaneous 1,4-cis selective and molecular weight control is possible in the polymerization of BD with the Co(acac)3/MAO catalyst.

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