Friction Coefficient of Polymer Molecules in Dilute Solution near the θ Point. 1. A Rapid Method for Determining Small Differences in Sedimentation Coefficients: Polystyrene in Cyclohexane

1980 ◽  
Vol 13 (5) ◽  
pp. 1207-1215 ◽  
Author(s):  
J. J. H. Mulderije
Keyword(s):  
Friction Coefficient ◽  
Rapid Method ◽  
Dilute Solution ◽  
Polymer Molecules ◽  
Θ Point

Eine schnelle Methode zur quantitativen Abtrennung von Chlor und Brom aus sauren wäßrigen Lösungen / A Rapid Method for the Quantitative Elimination of Chlorine or Bromine from Aqueous Acidic Solutions

1988 ◽  
Vol 43 (1) ◽  
pp. 134
Author(s):  
Wolfram Baumgärtner ◽  
Youssef A. Gawargious ◽  
Klaus Brodersen
Keyword(s):  
Aqueous Solutions ◽  
Rapid Method ◽  
Dilute Solution ◽  
Acidic Solutions

Abstract The quantitative elimination of chlorine and bromine from acidic aqueous solutions was achieved through extraction with a dilute solution of styrene in CCl4 .

Note on the distribution of polymer molecules in dilute solution

1950 ◽  
Vol 5 (3) ◽  
pp. 383-386 ◽  
Author(s):  
Paul M. Doty ◽  
Robert F. Steiner
Keyword(s):  
Dilute Solution ◽  
Polymer Molecules

The Association of Polymer Molecules in Dilute Solution.

1947 ◽  
Vol 51 (1) ◽  
pp. 32-57 ◽  
Author(s):  
Paul Doty ◽  
Herman Wagner ◽  
Seymour Singer
Keyword(s):  
Dilute Solution ◽  
Polymer Molecules

The direct observation of polymer molecules and determination of their molecular weight

1964 ◽  
Vol 279 (1376) ◽  
pp. 50-61 ◽  
Keyword(s):  
Molecular Weight ◽  
Direct Observation ◽  
Particle Diameter ◽  
Dilute Solution ◽  
Crystalline Polymers ◽  
Polymer Molecules ◽  
Molecular Weights ◽  
Preferential Evaporation ◽  
Poor Solvent

An experimental investigation of the conditions necessary for the production of compact, single polymer molecules, in a form suitable for direct observation in the electron microscope, is described. Molecules are isolated by dispersing a dilute solution of the polymer as fine droplets on to a suitable substrate: ideally each droplet should contain either one or no polymer molecules. The solution is a mixture of two solvents, a good one and a poor one. Initially the good solvent predominates so that the probability of polymer aggregation is low. Preferential evaporation of the relatively volatile solvent on the substrate itself gives the poor solvent conditions needed for the formation of well-defined molecular spheres. Factors determining the choice of solvent, precipitant, and the composition of the mixture are discussed. There is little difficulty in obtaining single molecules with glassy amorphus polymers; rubbery polymers collapse and spherical molecules are formed only if the entire preparation is carried out at a temperature below that of the glass transition; crystalline polymers are not amenable to this technique. To obtain sufficient contrast the particles have to be shadowed and it is shown that, although certain dimensions are distorted by the metal coating, the shadow length faithfully represents the true particle diameter. Molecular weights, and their distribution, when of the order of a million and above, can readily be accurately determined. Conventional methods are unreliable in this region of high molecular weight.

On the dimensions of intramolecularly crosslinked polymer molecules I. The synthesis and chemical characterization of intramolecularly crosslinked polystyrene molecules having a narrow distribution of molecular weight

1973 ◽  
Vol 334 (1599) ◽  
pp. 453-463 ◽  
Keyword(s):  
Molecular Weight ◽  
Secondary Amine ◽  
Chemical Characterization ◽  
Polymer Molecule ◽  
Dilute Solution ◽  
Polymer Molecules ◽  
Crosslinked Polymer ◽  
Crosslinked Polystyrene ◽  
Infrared Studies

The synthesis of intramolecularly crosslinked polystyrene molecules has bee nachieved by controlled chlormethylation of anionic polystyrene. The chlormethyl groups were reacted with n -butylamine and the secondary amine derivative thus produced was crosslinked by reaction with a diisocyanate in dilute solution. Samples were prepared containing a selected number of crosslinks in the range 5 to 150 per polymer molecule. The materials were completely soluble. The number of crosslinks in each sample was determined by quantitative infrared studies.

Change in the friction coefficient of the macromolecule during uncoiling in dilute solution

1989 ◽  
Vol 31 (6) ◽  
pp. 1249-1256 ◽  
Author(s):  
Yu.V. Brestkin ◽  
Yu.Ya. Gotlib ◽  
L.I. Klushin
Keyword(s):  
Friction Coefficient ◽  
Dilute Solution
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