Differential viscometry

FIGURE 10.14 Analysis of polyvinylpyridines on SynChropak CATSEC 100,300, and 1000 columns in series (250 X 4.6 mm i.d.). Flow rate 0.37 ml/min. Mobile phase 0.1 % trifluoroacetic acid in 0.2 N sodium nitrate. Detection by differential viscometry. (Reprinted from Ref. 9 with permission.)... 

Many proteins and polymers have been analyzed on SynChropak GPC and CATSEC columns. Table 10.6 lists some of the published applications. The use of a surfactant to analyze the caseins in milk is illustrated in Eig. 10.12. Viruses have also been analyzed on SynChropak GPC columns, as seen in the chromatogram from Dr. Jerson Silva of the University of Illinois (Pig. 10.13). Dr. Nagy and Mr. Terwilliger analyzed cationic polymers on a series of CATSEC columns using differential viscometry as detection (Pig. 10.14) (9). 

Synthetic, nonionic polymers generally elute with little or no adsorption on TSK-PW columns. Characterization of these polymers has been demonstrated successfully using four types of on-line detectors. These include differential refractive index (DRI), differential viscometry (DV), FALLS, and MALLS detection (4-8). Absolute molecular weight, root mean square (RMS) radius of gyration, conformational coefficients, and intrinsic viscosity distributions have... 

FIGURE 20.4 Differential viscometry chromatogram of fully hydrolyzed PVA using TSK-PW columns. 

Synchropak columns are very useful for characterizing hydrophilic, anionic, and nonionic, water-soluble polymers, CATSEC columns work best for characterizing cationic polymers utilizing both light scattering and/or differential viscometry detection over a wide range of molecular weights. 

Nagy, D. J. and Terwilliger, D. A., Size exclusion chromatography/differential viscometry of cationic polymers, J. Liq. Chromatogr., 12, 1431, 1989. 

Calculation of Results from Differential Viscometry and SEC. The familiar relationship first expressed by Mark (25) and Houwink (26) in the 1940 s is central to the concept of universal calibration first suggested by Benoit et al. (27). In this relationship,... 

DOSY NMR 2-dimensional diffusion ordered spectroscopy nuclear magnetic resonance (spectroscopy) dpb bis(dibenzylideneacetone) dppe 1,2-bis(diphenylphosphino)ethane DSC differential scanning calorimetry DV differential viscometry... 

D.J. Nagy, D.A. Terwilliger, B.D. Lawrey, W.F. Tiedge, Characterisation of cationic polymers by aqueous SEC/differential viscometry, presented at the International GPC Symposium, Newton, 1989. 

Also included in Table 3 are intrinsic viscosity data from differential viscometry and Ubbelohde viscometry. There is excellent agreement between the... 

The molecular weight of PVAc (the precursor to PVA) can be reliably measured in tetrahydrofuran (THF) using SEC-viscometry (33). The use of differential viscometry and LALLS provides a means to examine long-chain branching in the hydrolysis of PVAc to PVA. It is known that this hydrolysis results in the loss of hydrolyzable, long-chain branches that extend from the ester to the main PVAc backbone (10). Of course, branches formed by hydrogen abstraction and chain transfer to a carbon atom in the PVAc backbone are nonhydrolyzable and remain. 

Goldwasser, J.M. Absolute M determined by gel permeation cbromatograpby—differential viscometry. In Chromatography of Polymers Characterization by SEC and FFF Provder, T., Ed. ACS Symposium Series 521 ACS Washington, 1993 243-251. 

Replacement of fluorocarbon blowing agents Group transfer polymerization Differential viscometry 1990s Metallocene catalysts... 

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