Molecular Parameters of Hyperbranched Polymers Made by Self-Condensing Vinyl Polymerization. 1. Molecular Weight Distribution

1997 ◽  
Vol 30 (23) ◽  
pp. 7015-7023 ◽  
Author(s):  
Axel H. E. Müller ◽  
Deyue Yan ◽  
Michael Wulkow
Keyword(s):  
Molecular Weight ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Hyperbranched Polymers ◽  
Molecular Parameters ◽  
Vinyl Polymerization

Molecular Theories for the Viscoelasticity of Flexible Homogeneous Polymeric Liquids

2007 ◽  
Author(s):  
Chang Dae Han
Keyword(s):  
Molecular Weight ◽  
Rheological Properties ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Viscoelastic Behavior ◽  
Chain Branching ◽  
Molecular Parameters ◽  
Long Chain Branching ◽  
Polymeric Liquids ◽  
Long Chain

The fact that a polymer consists of a number of chains of different lengths, each in turn consisting of a series of monomer units, means that the motion of one part of the polymer chain will profoundly affect the motion of other parts. Hence, for a given polymer, a description of microscopic processes occurring under a given flow field depends on hypotheses regarding the molecular structure and mechanisms of flow in the polymer. Today, it is well-known, gained from practical experience, that the molecular weight, the molecular weight distribution, and the degree of long-chain branching influence the rheological properties of polymeric liquids. Therefore, a better understanding of the relationship between molecular parameters and rheological properties is very important from the standpoints of both polymer synthesis and polymer processing. However, the theoretical development of this aspect of the problem is far from complete, although some important progress has been made. In the preceding chapter, we discussed the viscoelastic behavior of polymeric liquids from the phenomenological point of view, without associating the significance of theoretical predictions to molecular origin(s). Specifically, we have seen that the rheological equations of state contain parameters that vary from polymer to polymer. Since it has amply been demonstrated by experiment that the extent of a particular viscoelastic behavior is greatly influenced by the molecular parameters, such as molecular weight, molecular weight distribution, and the degree of long-chain branching, predictions of any viscoelastic behavior of polymers on the basis of phenomenological theory is of very limited use to either control the quality of polymers produced or improve the performance of polymers, unless the parameters appearing in various continuum constitutive equations are related to molecular parameters.

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
Sign in / Sign up

Export Citation Format

Share Document