Light scattering characterization of an alternating copolymer of ethylene and tetrafluoroethylene. 2. Molecular weight distributions

1987 ◽  
Vol 20 (1) ◽  
pp. 98-103 ◽  
Author(s):  
Chi Wu ◽  
Warren Buck ◽  
Benjamin Chu
Keyword(s):  
Molecular Weight ◽  
Light Scattering ◽  
Alternating Copolymer ◽  
Molecular Weight Distributions ◽  
Weight Distributions

Mechanical and Viscoelastic Characterization of Hyperbranched Polyisobutylenes

2002 ◽  
Vol 75 (5) ◽  
pp. 853-864 ◽  
Author(s):  
Judit E. Puskas ◽  
Christophe Paulo ◽  
Volker Altstädt
Keyword(s):  
Molecular Weight ◽  
Butyl Rubber ◽  
Structure Property ◽  
Carbocationic Polymerization ◽  
Molecular Weights ◽  
Structure Property Relationships ◽  
Molecular Weight Distributions ◽  
Weight Distributions ◽  
Living Carbocationic Polymerization

Abstract Structure-property relationships were investigated in hyperbranched polyisobutylenes, in comparison with commercial linear butyl rubber. The gel-free, soluble hyperbranched polyisobutylenes, synthesized by living carbocationic polymerization, had molecular weights, Mw≈400,000 to 1,000,000 g/mol, molecular weight distributions, MWD ≈1.2 to 2.6, and branching frequencies, BR ≈ 4 to 60. The mechanical and viscoelastic characterization of these polymers revealed interesting properties, including the characteristics of crosslinked rubbers.

scholarly journals Preparation and Characterization of Poly(2-vinylpyridine) with Narrow Molecular Weight Distributions

1986 ◽  
Vol 18 (4) ◽  
pp. 361-366 ◽  
Author(s):  
Yushu Matsushita ◽  
Kunio Shimizu ◽  
Yasushi Nakao ◽  
Haruhisa Choshi ◽  
Ichiro Noda ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Molecular Weight Distributions ◽  
Weight Distributions

Synthesis and Properties of Uniform Polyisoprene Networks. I. Synthesis and Characterization of α,ω-Dihydroxy-Polyisoprene

1976 ◽  
Vol 49 (2) ◽  
pp. 303-319 ◽  
Author(s):  
M. Morton ◽  
L. J. Fetters ◽  
J. Inomata ◽  
D. C. Rubio ◽  
R. N. Young
Keyword(s):  
Molecular Weight ◽  
Physical Properties ◽  
Soluble Fraction ◽  
Synthesis And Characterization ◽  
Molecular Weights ◽  
Molecular Weight Distributions ◽  
Weight Distributions ◽  
The Subject

Abstract The results of this study are the first to show that high-1,4 linear α,ω-dihydroxypolydienes can be synthesized with (a) predictable molecular weights, (b) narrow molecular weight distributions, and (c) high functionalities. Using the functionalized polyisoprenes prepared in this work, a series of networks was prepared with a purified triisocyanate as the chain linking agent. The soluble fraction in these networks ranged from 4.6 to 1.6 per cent. The characteristics and physical properties of these networks will be the subject of a forthcoming publication.

Characterization of Molecular Weight Distributions by the Standard Deviation

1971 ◽  
Vol 5 (2) ◽  
pp. 459-468 ◽  
Author(s):  
John G. Watterson ◽  
Hans-Georg Elias
Keyword(s):  
Molecular Weight ◽  
Standard Deviation ◽  
Molecular Weight Distributions ◽  
Weight Distributions

Determination of Copolymer Molecular Weight

1968 ◽  
Vol 41 (1) ◽  
pp. 245-253 ◽  
Author(s):  
Paul Rempp ◽  
Henri Benoit
Keyword(s):  
Molecular Weight ◽  
Light Scattering ◽  
Density Gradient ◽  
Compositional Heterogeneity ◽  
Precise Information ◽  
Molecular Weights ◽  
Molecular Weight Distributions ◽  
Weight Distributions ◽  
Binary Copolymers

Abstract From this brief review it appears that determinations of molecular weight averages, of molecular weight distributions, and of compositional inhomogeneity of binary copolymers, require care in the choice of techniques and methods. Some of the most commonly used techniques for molecular weight determinations on homopolymers of various kinds are inadequate for the same determinations on copolymers. Others are more sensitive to fluctuations in composition than in molecular weights. Osmotic methods are the only one which are really insensitive to inhomogeneity, and which yield molecular weights. Ultracentrifugation in a density gradient yields precise information only on fluctuations in composition. Viscosity determinations require calibration, but even so, they may lead to erroneous values of the molecular weight in the case of copolymers. GPC is less sensitive to compositional heterogeneity, but cannot be applied for nonlinear copolymers. Finally, light scattering is a very powerful tool for studies on copolymers, since it leads to molecular weight averages and its helps characterize polydispersity and fluctuations in composition.

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