Lattice theory for binding of linear polymers to a solid substrate from polymer melts: I. Influence of chain connectivity on molecular binding and adsorption

2019 ◽  
Vol 151 (12) ◽  
pp. 124706 ◽  
Author(s):  
Jacek Dudowicz ◽  
Jack F. Douglas ◽  
Karl F. Freed
Keyword(s):  
Lattice Theory ◽  
Polymer Melts ◽  
Solid Substrate ◽  
Linear Polymers ◽  
Molecular Binding

Modeling the Rheology of Commercial Long Chain Branched Polymer Melts

2003 ◽  
Vol 804 ◽  
Author(s):  
Seung Joon Park ◽  
Ronald G. Larson
Keyword(s):  
Experimental Data ◽  
Hierarchical Model ◽  
Polymer Melts ◽  
Quantitative Agreement ◽  
Branched Polymers ◽  
Linear Polymers ◽  
Branched Polymer ◽  
Long Chain Branching ◽  
Wide Range ◽  
Long Chain

ABSTRACTThe predictions of a general “hierarchical model” for the rheology of general mixtures of linear and branched polymers are compared to experimental data for well-defined long-chain branched polymers. For a wide range of branched polymer melts, which include star-linear blends, H-polymers, and comb polymers, the predictions of the model agree well with experimental data. We apply the hierarchical model to metallocene-catalyzed polyethylenes (mPEs), in which the branched structures are generated by a Monte Carlo method based on the known reaction kinetics. The hierarchical model captures the shape of the curves of viscoelastic moduli vs. frequency of mPEs well and predicts accurately the effect of long chain branching on the linear viscoelastic properties. The quantitative agreement of the hierarchical model prediction with experimental data of well-defined long-chain branched polymers and mPEs shows that information on branching structure could be inferred from rheological measurements on combinatorial sets of mixtures of an unknown branched with different combinations of linear polymers.

scholarly journals Analytical Rheology of Polymer Melts: State of the Art

2012 ◽  
Vol 2012 ◽  
pp. 1-24 ◽  
Author(s):  
Sachin Shanbhag
Keyword(s):  
Molecular Weight ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Polymer Melts ◽  
State Of The Art ◽  
Branched Polymers ◽  
Linear Polymers ◽  
Rheological Measurements ◽  
Unknown Sample ◽  
Extreme Sensitivity

The extreme sensitivity of rheology to the microstructure of polymer melts has prompted the development of “analytical rheology,” which seeks inferring the structure and composition of an unknown sample based on rheological measurements. Typically, this involves the inversion of a model, which may be mathematical, computational, or completely empirical. Despite the imperfect state of existing models, analytical rheology remains a practically useful enterprise. I review its successes and failures in inferring the molecular weight distribution of linear polymers and the branching content in branched polymers.

On the surface tension of directed linear polymers

1989 ◽  
Vol 50 (6) ◽  
pp. 599-608 ◽  
Author(s):  
V.B. Priezzhev ◽  
S.A. Terletsky
Keyword(s):  
Surface Tension ◽  
Linear Polymers

Arrangement Of Monomeric Units In Fibrin

1979 ◽  
Author(s):  
Jan Hermans
Keyword(s):  
Fiber Axis ◽  
High Symmetry ◽  
Linear Polymers ◽  
Fiber Volume ◽  
High Fiber ◽  
Rotation Axes ◽  
Small Set ◽  
Helical Turn ◽  
The One ◽  
Kinetics Of

Measurements of light scattering have given much information about formation and properties of fibrin. These studies have determined mass-length ratio of linear polymers (protofibrils) and of fibers, kinetics of polymerization and of lateral association and volume-mass ratio of thick fibers. This ratio is 5 to 1. On the one hand, this high value suggests that the fiber contains channels that allow the diffusion of enzymes such as Factor XHIa and plasmin; on the other hand, the high value appears paradoxical for a stiff fiber made up of elongated units (fibrin monomers) arranged in parallel. Such a high fiber volume is a property of only a small set out of many high-symmetry models of fibrin, which may be constructed from overlapping three-domain monomers which are arranged into strands, are aligned nearly parallel to the fiber axis and make adequate longitudinal and lateral contacts. These models contain helical protofibrils related to each other by rotation axes parallel to the fiber axis. The protofibrils may contain 2, 3 or 4 monomers per helical turn and there are four possible symmetries. A large specific volume is achieved if the ends of each monomer are slightly displaced from the protofibril axis, either by a shift or by a tilt of the monomer. The fiber containing tilted monomers is more highly interconnected; the two ends of a tilted monomer form lateral contacts with different adjacent protofibrils, whereas the two ends of a non-tilted monomer contact the same adjacent protofibril(s).

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