Effect of Core-Forming Molecules on Molecular Weight Distribution and Degree of Branching in the Synthesis of Hyperbranched Polymers

1998 ◽  
Vol 31 (2) ◽  
pp. 239-248 ◽  
Author(s):  
Wolfgang Radke ◽  
Galina Litvinenko ◽  
Axel H. E. Müller
Keyword(s):  
Molecular Weight ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Hyperbranched Polymers ◽  
Degree Of Branching

Rheology and Molecular Weight Distribution of Hyperbranched Polymers

2002 ◽  
Vol 35 (25) ◽  
pp. 9605-9612 ◽  
Author(s):  
Suneel ◽  
D. M. A. Buzza ◽  
D. J. Groves ◽  
T. C. B. McLeish ◽  
D. Parker ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Hyperbranched Polymers

Molecular Weight Distribution of Polystyrene and of Butadiene-Styrene Copolymers Prepared in Emulsion Systems

1970 ◽  
Vol 43 (6) ◽  
pp. 1424-1438
Author(s):  
C. A. Uraneck ◽  
J. E. Burleigh
Keyword(s):  
Molecular Weight ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Homologous Series ◽  
Degree Of Branching ◽  
Styrene Copolymers ◽  
Divinyl Benzene ◽  
Emulsion Systems ◽  
Molecular Weight Fractions ◽  
Butadiene Styrene

Abstract Polystyrene and butadiene—styrene copolymers (SBR) were parepared in emulsion systems with a homologous series of commercial mercaptan modifiers. The molecular weight distribution (MWD) of the sets of polymers changed in a consistant manner when the regulating index of the mercaptan was relatively low. However the shape of the MWD curves appeared distorted in comparison to theoretical curves when the modifier depleted rapidly and when divinyl-benzene was present in the system. The divergence from the theoretical curve is attributed to a higher degree of branching in the high molecular weight fractions. Differences in MWD of SBR made with n- and tert-dodecyl mercaptans was marked. Notable differences were also found for SBR 1500 samples from the industry at random, but only slight differences were seen in a set of SBR 1503 samples. This study shows how the MWD of polymers prepared in emulsions can be varied simply by use of modifiers with different regulating indexes.

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