Chromatogram, gel permeation

Table 9,4 Data for the Analysis of the Gel Permeation Chromatogram of a Poly disperse Polymer Used in Example 9.7...

Figure 15 Typical gel permeation chromatograms of polyethylenes (HDPEs). (-(—) new generation super flow resin. Source Ref. 116.

The gel permeation chromatogram shown in Fig. 6 illustrates the purity of a block copolymer obtained by ion coupling. It is seen that about 5% of uncoupled block copolymer contaminates a triblock copolymer of narrow molecular weight distribution. The synthesis of star block polymers owes its recent development to the use of new coupling agents412. ... 

Fig. 6. Gel permeation chromatogram of the MS-PS-MS block copolymers obtained by coupling...

The effect is that the polymer molecules are separated into fractions. These are measured by an appropriate detector located at the end of the column, and the detector records the response as a peak on a chart. The chromatogram thus consists of a series of peaks corresponding to different elution volumes, the shortest elution volume being due to the largest molar mass polymer molecules within the sample. Details of the molar mass distribution can be determined from the size and number of the individual peaks in the chromatogram. An example of a gel permeation chromatogram is shown as Figure 6.4. 

Gel permeation chromatograms actually give information about molecular size. For any polymer, size is determined hy a number of factors. These include not only molar mass but also temperature and thermodynamic quality of the solvent. Hence the relationship between size and molar mass is unique for each particular polymer-solvent combination, and we caimot assume that because two peaks of different polymers, even in the same solvent at the same temperature, have the same elution volume their molecules have the same molar mass. 

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

Tung, L. H., Method of calculating molecular-weight-distribution functions from gel permeation chromatogram, /. Appl. Polym. Sci., 10, 375, 1966. 

The possibility exists that the acid used in hydrolysis could catalyze the hydrolysis of the succinic ester group in the middle of the telechelomer itself. Even though NMR ( H and C) cannot easily eliminate this possibility, we have evidence that such a hydrolysis did not take place. For instance, hydrolysis should result in the formation of poly(pivalolactone) which is insoluble both in methylene chloride and water, but no insolubles were evident. Also, the Gel Permeation Chromatograms do not show impurities in the product. 

A TEA/DIBAH mixture can be added to cold (-78°C) monomer until the stable colored complex forms. The purification reaction is then allowed to proceed for 60 minutes at room temperature. This procedure allows for removal of impurities without reduction of the ester. Significantly narrower gel permeation chromatograms (Mw/Mn <1.25) of poly(t-butyl methacrylate) are obtained when the samples are prepared from TEA/DIBAH purified monomer. 

Figure 12. Gel Permeation Chromatograms of Chemically Modified PBD (90% 1,2 units)...

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

The polymers of 1,4-hexadienes have unusually wide molecular weight distributions. This is illustrated by the gel permeation chromatogram of the methanol-insoluble fraction of poly(5-methyl-1,4-hexadiene) in tetrahydrofuran (Figure 9). The polymer was obtained in 82% conversion and had an inherent viscosity of 2.1 dl./g. in toluene at 25°C. 

Figure 9. Gel permeation chromatogram of methanol-isoluble fraction of poly(5-methyl-1,4-hexadiene). THF solvent.

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].

Figure 5.2. Gel permeation chromatogram (GPC) of the liquid silicon precursor for Si film formation for (a) cyclopentasilane (CPS) and (b) UV-irradiated CPS, both of which were diluted with toluene (1 vol.%) before GPC measurements. The UV-irradiation conditions were 405 nm, 100mW/cm2, and a 10-min irradiation for 1cm3 of CPS. The broad peak around Mw = 2600 corresponds to polysilanes of various molecular weights, as a result of the photo-induced polymerization of CPS. [Reproduced with permission from Ref. 10. Copyright 2006 Nature Publishing Group.]...

Figure 2. Gel Permeation Chromatogram of the copolymer (a) before and (b) after removal of the t-BOC protecting groups...

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

Figure 3.36 Gel permeation chromatogram. All molecules larger than the exclusion limit of the gel appear at V0 (the void volume). Molecules which can gain access to the gel structure to varying degrees are eluted in order of decreasing size.

An example for the synthesis of poly(2,6-dimethyl-l,4-phenylene oxide) - aromatic poly(ether-sulfone) - poly(2,6-dimethyl-1,4-pheny-lene oxide) ABA triblock copolymer is presented in Scheme 6. Quantitative etherification of the two polymer chain ends has been accomplished under mild reaction conditions detailed elsewhere(11). Figure 4 presents the 200 MHz Ir-NMR spectra of the co-(2,6-dimethyl-phenol) poly(2,6-dimethyl-l,4-phenylene oxide), of the 01, w-di(chloroally) aromatic polyether sulfone and of the obtained ABA triblock copolymers as convincing evidence for the quantitative reaction of the parent pol3rmers chain ends. Additional evidence for the very clean synthetic procedure comes from the gel permeation chromatograms of the two starting oligomers and of the obtained ABA triblock copolymer presented in Figure 5. 

Figure 3. Gel permeation chromatograms of PMMA exposed to increasing doses of y radiation. High molecular weight fractions elute at low elution...

Figure 8.1 Gel permeation chromatograms related to the radical initiated degradation of poly(phenylhydrosilane) (2). (A) Initial sample with M = 2320 and Mw/Mn = 1.67. (B) Sample obtained after 5 h heating at 50 °C of a benzene solution containing 0.09 M of 2 in the presence of t-BuONNOBu-t (lOmol %) M = 840 and Mw/Mn = 1.28. (C) Sample obtained after Ih heating at 140 °C of a crt-butylbenzene solution containing 0.09 M of 2 in the presence of t-BuOOBu-t (10 mol %) Mw = 750 and Mw/Mn = 1.29.

Figure 1. Gel permeation chromatogram of -alkanes. Conditions 6l0 mm X 8 mm TSKG 2000 h8 column and tetrahydro-furan eluant at 0.5 mL/mln. Key 1, 2, n...

Figure 3. Gel permeation chromatogram of nonylphenol-formaldehyde adducts with dual detectors.

Figure U. Gel permeation chromatogram of polymerized acetone-aniline condensation products. Key 3 5- and 6-TMDQ oligomers and 1,2- and U-ollgomeric series from a different addition route.

Figure 5- Gel permeation chromatogram of butylated -cresol-dicyclopentadiene reaction products.

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