From dynamic moduli to molecular weight distribution: A study of various polydisperse linear polymers

1997 ◽  
Vol 41 (5) ◽  
pp. 1203-1220 ◽  
Author(s):  
Christian Carrot ◽  
Jacques Guillet
Keyword(s):  
Molecular Weight ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Linear Polymers ◽  
Dynamic Moduli

Evaluation of molecular weight distribution from dynamic moduli

2001 ◽  
Vol 40 (2) ◽  
pp. 111-119 ◽  
Author(s):  
Maria Rossella Nobile ◽  
Franco Cocchini
Keyword(s):  
Molecular Weight ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Dynamic Moduli

Evaluation of molecular weight distribution in linear polymers from rheological measurements

1972 ◽  
Vol 14 (10) ◽  
pp. 2653-2656 ◽  
Author(s):  
V.A. Grechanovskii ◽  
I.Ya. Poddubnyi ◽  
L.A. Nedoinova ◽  
Yu.G. Kamenev
Keyword(s):  
Molecular Weight ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Linear Polymers ◽  
Rheological Measurements

Synthesis and Dilute-Solution Behavior of Model Star-Branched Polymers

1978 ◽  
Vol 51 (3) ◽  
pp. 406-436 ◽  
Author(s):  
B. J. Bauer ◽  
L. J. Fetters
Keyword(s):  
Molecular Weight ◽  
Physical Properties ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Average Molecular Weight ◽  
Melt Processing ◽  
Branched Polymers ◽  
Linear Polymers ◽  
Dilute Solution ◽  
Long Chain

Abstract The occurrence of polymers branched in a random fashion is common. Chain transfer reactions can cause short- and long-chain branching in polymerizations such as the high-pressure polymerization of ethylene. Branching can also be introduced intentionally by the use of a polyfunctional monomer in end-linking polymerizations. Similar branching can be produced in addition polymerizations by the use of a small amount of difunctional monomer, e.g., divinylbenzene. There also has been much interest in graft polymerization by which long chain branches can be introduced onto a backbone, which is often a different polymer from the branches. The properties of branched polymers can be quite different from those of linear polymers of the same molecular weight. For example, bulk viscosities as well as concentrated and dilute solution viscosities can be lower for branched polymers than for a linear material of equivalent molecular weight. As an example, the melt processing behavior of polymers can be manipulated by alterations in the average molecular weight, molecular weight distribution, and the frequency and length of long branches in the molecules. Thus, there is an obvious need to correlate and characterize the type and degree of branching in a polymer with its effect on the physical properties in solution or melt. In all of the above examples of branching, there is a mixture of branched and unbranched material. The unbranched and branched polymers can have a wide molecular weight distribution, as can the branches themselves. Also, the frequency of branches and the segment lengths between branch points can vary. Hence, the physical properties of such materials represent an average of the properties of all the different species present.

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