Intrinsic viscosity of polymers of low molecular weight

1968 ◽  
Vol 6 (10) ◽  
pp. 1759-1772 ◽  
Author(s):  
Umberto Bianchi ◽  
Anton Peterlin
Keyword(s):  
Molecular Weight ◽  
Intrinsic Viscosity ◽  
Low Molecular Weight

Intrinsic viscosity–molecular weight relationship for low molecular weight nylon 6

1968 ◽  
Vol 12 (9) ◽  
pp. 2105-2109 ◽  
Author(s):  
P. Hague ◽  
M. B. Huglin ◽  
B. L. Johnson ◽  
J. Smith
Keyword(s):  
Molecular Weight ◽  
Intrinsic Viscosity ◽  
Nylon 6 ◽  
Low Molecular Weight ◽  
Weight Relationship

Sodium-Catalyzed Copolymerization of 1,3-Butadiene and Styrene

1947 ◽  
Vol 20 (1) ◽  
pp. 1-13
Author(s):  
C. S. Marvel ◽  
W. J. Bailey ◽  
G. E. Inskeep
Keyword(s):  
Molecular Weight ◽  
Intrinsic Viscosity ◽  
Side Chain ◽  
Low Molecular Weight ◽  
Monomer Mixture ◽  
Laboratory Procedure ◽  
Styrene Content ◽  
Polymerization Method

Abstract 1. A convenient laboratory procedure for the sodium-catalyzed copolymerization of butadiene and styrene has been described. Earlier attempts to accomplish this probably failed because the monomers were not sufficiently pure. 2. The copolymer of butadiene and styrene which results from sodium polymerization is different from the emulsion copolymer, GR-S, in several important respects. The sodium-catalyzed copolymer has a more nearly constant styrene content at different stages of conversion; it is made up of molecules with a relatively narrow molecular weight spread; it has a higher intrinsic viscosity; it is 100 per cent soluble in benzene (i.e., there is no gel) even at 100 per cent conversion; when treated with standard rubber antioxidant, it ages better; and it has a greater amount of the butadiene joined in the 1,2 manner (i.e., greater vinyl side-chain content). 3. The effects of such variables as temperature of polymerization, method of adding the monomer mixture to the catalyst, size of catalyst particles, and possible butadiene impurities on the polymerization have been studied. 4. The method has been extended to cover copolymerization of butadiene and m-methylstyrene to give a soluble copolymer of low molecular weight. Other styrene-type monomers gave less interesting copolymers.

The Synthesis of Benzothiazole Polymers with Perpendicularly Attached Phenyl Substituents

1988 ◽  
Vol 134 ◽  
Author(s):  
William A. Feld ◽  
YiHua Chang ◽  
John D. Peak ◽  
Scott G. Wierschke ◽  
Join Pin Chen
Keyword(s):  
Molecular Weight ◽  
Intrinsic Viscosity ◽  
Low Molecular Weight ◽  
Enhanced Solubility

ABSTRACTA series of 2-aryl-4,7-benzothiazoledicarboxylic acids have been synthesized from the corresponding dimethyl derivatives. These derivatives contain the phenyl, and the p-bromo-, mchloro-, p-chloro-, m-methoxy-, and p-methoxyphenyl aryl substituents. The phenyl, pchlorophenyl and p-methoxyphenyl substituted diacids were polymerized with 2,5-diamino-1,4- benzenedithiol dihydrochloride to yield the corresponding poly(benzothiazole)s. The polymers were of low molecular weight (intrinsic viscosity as high as 1.7) and did not show enhanced solubility in common solvents.

Relationship between intrinsic viscosity and mean molecular weight of polyvinylpyrrolidone in the low-molecular-weight region

1979 ◽  
Vol 13 (10) ◽  
pp. 1104-1104 ◽  
Author(s):  
T. M. Karaputadze ◽  
V. I. Svergun ◽  
S. V. Tarabakin ◽  
V. P. Panov ◽  
Yu. �. Kirsh
Keyword(s):  
Molecular Weight ◽  
Intrinsic Viscosity ◽  
Low Molecular Weight ◽  
Mean Molecular Weight

Extraction and Partial Characterisation of Hydrocolloid Gums from Some African Legumes

2011 ◽  
Vol 7 (3) ◽  
Author(s):  
Clément Saidou ◽  
Jean Bosco Tchatchueng ◽  
Robert Ndjouenkeu ◽  
Denis CD Roux
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Intrinsic Viscosity ◽  
The Other ◽  
Low Molecular Weight ◽  
Water Emulsion ◽  
Viscosity Measurements ◽  
Galactose Residue ◽  
Partial Characterisation ◽  
Oil Water

In an attempt to understand the potential valorisation of local African legumes, hydrocolloids of five legumes (Corchorus olithorus, Triumfetta cordifolia, Cerathoteca sesamoides, Adansona digitata, and Bridelia thermifolia) were extracted and characterised as polysaccharides. All the gum extracted were rich in galactose residue (31-62 percent), suggesting a galactan backbone for the polysaccharides structure. The other sugar residues of the polysaccharides were arabinose (22-30 percent) in T. cordifolia and B. thermifolia, glucose (22-36 percent) in B. thermofolia, A. digitata and C. olithorus, and mannose (32.9 percent) in C. sesamoides. The intrinsic viscosity measurements showed that gums from T. cordifolia, B. thermifolia, C sesamoides and C. olithorus are high molecular weight polymers, while A. digitata contains low molecular weight polymers. The gum extracts also showed oil/water emulsion activity and were able to keep 60-90 percent of the emulsion stable on heating.

PHYSICOCHEMICAL STUDIES OF LIGNINSULPHONATES: II. BEHAVIOR AS POLYELECTROLYTES

1955 ◽  
Vol 33 (10) ◽  
pp. 1491-1501 ◽  
Author(s):  
J. L. Gardon ◽  
S. G. Mason
Keyword(s):  
Molecular Weight ◽  
Aqueous Solutions ◽  
High Molecular Weight ◽  
Intrinsic Viscosity ◽  
Micelle Formation ◽  
Low Molecular Weight ◽  
Molecular Weights ◽  
Physicochemical Studies ◽  
Molecular Weight Fractions ◽  
Molecular Branching

Conductivity, dyestuff adsorption, and viscosity measurements on aqueous solutions of fractionated ligninsulphonate samples having various molecular weights indicate that they behave as flexible polyelectrolytes. There is evidence that ligninsulphonates of molecular weight less than 5000 associate in solution in a manner analogous to micelle formation in colloidal electrolytes. From the variation of intrinsic viscosity with molecular weight, it may be concluded that the degree of molecular branching of the high molecular weight ligninsulphonates is greater than that of the low molecular weight fractions.

Mesophase formation and intrinsic viscosity for some low-molecular-weight cellulose acetate samples

1989 ◽  
Vol 5 (6) ◽  
pp. 1711-1718 ◽  
Author(s):  
M. H. Godinho ◽  
M. J. Seurin ◽  
P. Maïssa ◽  
P. Sixou
Keyword(s):  
Molecular Weight ◽  
Cellulose Acetate ◽  
Intrinsic Viscosity ◽  
Low Molecular Weight ◽  
Mesophase Formation

A high-performance oil-free backing pump for electron microscopes

1978 ◽  
Vol 36 (1) ◽  
pp. 110-111
Author(s):  
G.K.W. Balkau ◽  
E. Bez ◽  
J.L. Farrant
Keyword(s):  
Molecular Weight ◽  
Electron Microscope ◽  
Hot Spots ◽  
High Performance ◽  
Carbonaceous Material ◽  
Contamination Rate ◽  
Low Molecular Weight ◽  
Principal Source ◽  
Rotary Pumps ◽  
Electron Microscopes

The earliest account of the contamination of electron microscope specimens by the deposition of carbonaceous material during electron irradiation was published in 1947 by Watson who was then working in Canada. It was soon established that this carbonaceous material is formed from organic vapours, and it is now recognized that the principal source is the oil-sealed rotary pumps which provide the backing vacuum. It has been shown that the organic vapours consist of low molecular weight fragments of oil molecules which have been degraded at hot spots produced by friction between the vanes and the surfaces on which they slide. As satisfactory oil-free pumps are unavailable, it is standard electron microscope practice to reduce the partial pressure of organic vapours in the microscope in the vicinity of the specimen by using liquid-nitrogen cooled anti-contamination devices. Traps of this type are sufficient to reduce the contamination rate to about 0.1 Å per min, which is tolerable for many investigations.

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