Polystyrene chromatogram

Figures 6.14-6.16 show the chromatograms of polystyrene, polyethylene glycol, and polyethylene oxide standards using dimethylformamide (DMF) as an eluent.

Figure 9.7 shows separations under identical conditions using PSS SDV columns with 3 (Fig. 9.7a)-, 5 (Fig. 9.7b)- and 10 (Fig. 9.7c)-/i,m particle size columns. A polystyrene oligomer standard was injected and all analyses were performed in THF as the eluent. The much higher efficiencies of small particle size columns are obvious, which is important in the SEC separation of low molecular weight compounds such as additives, by-products, and resins. The reader should note that all chromatograms are area normalized and have the same Y axis to show the differences in peak width and height. 

FIGURE 9.9 Definition of column test parameters using a SEC chromatogram of a polymer standard mixture (PSS Polystyrene ReadyCal) and a low molar mass compound (BHT). 

FIGURE 11.4 Comparison of chromatograms obtained on conventional (A) and solvent-efficient Styragel columns (B). In each case the column bank was a bank of Styragel HR 0.5, HR I, HR 2, and HR 3 columns at 3S°C with THF as the solvent. The sample is a mixture of polystyrene standards. With proper care and optimized instrumentation, good resolution can be obtained with solvent-efficient Styragel columns. (Courtesy of Waters Corp.)... 

Gel Permeation Chromatography. The instrument used for GPC analysis was a Waters Associates Model ALC - 201 gel permeation chromatograph equipped with a R401 differential refractometer. For population density determination, polystyrene powder was dissolved in tetrahydrofuran (THF), 75 mg of polystyrene to SO ml THF. Three y -styragel columns of 10, 10, 10 A were used. Effluent flow rate was set at 2.2 ml/min. Total cumulative molar concentration and population density distribution of polymeric species were obtained from the observed chromatogram using the computer program developed by Timm and Rachow (16). 

Figure 6.4 A typical gel permeation chromatogram using monodisperse polystyrene standards...

One possibility is that although averages for polystyrene standards require correction, those for PMMA would not According to symmetrical axial dispersion theory (5) the correction depends upon both the slope of the calibration curve (different for each polymer type) and the variance of the chromatogram of a truly monodisperse sample. Furthermore, the calibration curve to be utilized can be obtained from a broad standard as well as from monodisperse samples. The broad standard method may itself incorporate some axial dispersion correction depending upon how the standard was characterized. 

Figure 8. Typical polystyrene n-butyl methacrylate chromatogram (low to intermediate conversions) showing monomer peaks at times 46.2 and 49.2 min resolved...

Figure 20 shows an example of its use. As expected, the GPC 2 chromatogram of a fraction of a monodisperse standard (obtained by sampling it with GPC 2 at its peak) is narrower than the whole standard which in turn is narrower than chromatograms of slices of broad polystyrene distributions. In Figure 20, two examples of the latter show the difference obtained by improving resolution in GPC 1. 

Figure 2. Size exclusion chromatograms of polystyrene standard (A) and p(t-butyl styrene)-b-PSX (B).

Figure 2 Chromatogram from conventional SEC column compared to high-speed SEC column tested on an identical instrument with polystyrene standards in tetrahydrofuran (THF). (See Color Plate Section at the end of this book.)...

Figure 14. Gel permeation chromatograms of polystyrene and polystyrene-polybutadiene diblock copolymer prepared with Ba-Mg-Al. Conditions solvent, cyclohexane 50° C.

Figure 12. Gel permeation chromatogram of latex polymer separated from composite silica-polystyrene latex system, SPL(HPC).

Figure 13. Gel permeation chromatogram of polystyrene latex, (PL), prepared by emulsifier-free emulsion polymerization at 1 5 °C(in the absence of silica particles).

Fig. 55. Gel-permeation chromatogram(GPC) of a microgel sample of Mw = 10X106 g/mol obtained in the anionic polymerization of EDMA in toluene. Microgel concentration = 1 g/L solvent = butyl acetate elution temperature = 70 °C is the weight-average molar mass of linear polystyrene used for comparison. [Reproduced from Ref. 256 with permission, Huthig Wepf Publ., Zug, Switzerland].

Fig A typical gel permeation chromatogram polystyrene in tetrahydrofuran, which Ms/Mw = 2.9. 

Figure 3.14 Reversed-phase liquid chromatogram of polystyrene oligomers. Conditions. ...

Methacrylate polymers are as physically strong as polystyrene gels. Their hydrophobicity is weaker than that of polystyrene gel, and the aromatic selectivity is similar to that of octadecyl-bonded silica gel. A chromatogram of hydantoins on a methacrylate polymer is shown in Figure 3.16. The elution order is related to the hydrophobicity of the chemicals. 

Figure 3.15 Chromatogram of fibre-type proteins on polystyrene gels having different pore sizes. Column A, PLRP-S 300 A, 15 cm x 4.6 mm i.d. B, PLRP-S 1000 A (polystyrene gel), 15 cm x 4.6 mm i.d. eluent, 15 min linear gradient from 20% of 0.25% trifluoroacetic acid to 60% of 0.25% trifluoro-acetic acid in 95% aqueous acetonitrile flow rate, 1.0 ml min-1 detection, UV220 nm. Peaks 1, collagen (Mr 120 000) and 2, fibrinogen (Mr 340 000). (Reproduced by permission from Polymer Laboratories data)...

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