Poly size exclusion chromatography

Poly(ethylene oxide). The synthesis and subsequent hydrolysis and condensation of alkoxysilane-terniinated macromonomers have been studied (39,40). Using Si-nmr and size-exclusion chromatography (sec) the evolution of the siUcate stmctures on the alkoxysilane-terniinated poly(ethylene oxide) (PEO) macromonomers of controlled functionahty was observed. Also, the effect of vitrification upon the network cross-link density of the developing inorganic—organic hybrid using percolation and mean-field theory was considered. 

Figure 3 Reversed-phase chromatography of products after alkaline hydrolysis of /3-poly(L-malate), Discrete polymer products are formed, which differ in length by several units of L-malate. The absorbance at 220-nm wavelength was measured, (a) /3-Poly(L-malate) before hydrolysis, (b) After 10-min incubation in 20 mM NaOH at 37°C. (c) After 15 h in 20 mM NaOH at 37°C. (d) After I h in 500 mM NaOH at 100°C. High pressure chromatography (HPLC) on Waters reversed-phase Ci8- i-Bondapak. The methanol gradient (in water-trifluoro acetic acid, pH 3.0) was programmed as follows 0-40 min 0.3-23%, 40-47 min 23-40%, 47-49 min 40%, 49-54 min 40-0%. (d) Inset size exclusion chromatography after 3-min alkaline hydrolysis at pH 10.2. BioSil SEC 250 column of 300 mm x 7.8 mm size, 0.2 M potassium phosphate buffer pH 7.0.

A second project [10] was based on the production of Pd nanocluster inside poly-methacrylic acid (8%mol)-A,iV-di-methylacrylamide (88 % mol)-A, A -methylenebisacrylamide (4% mol). ISEC (Inverse Size Exclusion Chromatography) analysis of the resin in water in terms of cylindrical pores [7]... 

Wu, C. S., Senak, L., and Malawer, E. G., Size exclusion chromatography of poly(methyl vinyl ether-co-maleic anhydride) (PMVEMA). I. The chromatographic method, J. Liq.Chromatogr., 12, 2901, 1989. 

Mori, S., Secondary effects in aqueous size exclusion chromatography of sodium poly(styrene sulfonate) compounds, Anal. Chem., 61, 530, 1989. 

Huve, P., Verrecchia, T., Bazile, D., Vauthier, C., and Couvreur, C., Simultaneous use of size exclusion chromatography and photon correlation spectroscopy for the characterization of poly(lactic acid) nanoparticles, /. Chromatogr. A, 675, 129, 1994. 

We report here the results of our recent studies of poly(alkyl/arylphosphazenes) with particular emphasis on the following areas (1) the overall scope of, and recent improvements in, the condensation polymerization method (2) the characterization of a representative series of these polymers by dilute solution techniques (viscosity, membrane osmometry, light scattering, and size exclusion chromatography), thermal analysis (TGA and DSC), NMR spectroscopy, and X-ray diffraction (3) the preparation and preliminary thermolysis reactions of new, functionalized phosphoranimine monomers and (4) the mechanism of the polymerization reaction. 

Figure 15.1. MALDI spectrum of a polycarbonate sample along with peak assignment. In the inset, an expansion of the spectral region from 3.0 up to 3.7 kDa is shown. (Reproduced from Puglisi, C. et al., 1999. Analysis of Poly(bisphenol A Carbonate) by Size Exclusion Chromatography/Matrix-Assisted Laser Desorption/lonization. I. End Group and Molar Mass Determination. Rapid Communications in Mass Spectrometry, 13 2260-2267. With permission of John Wiley Sons, Inc.)...

Fig. 12. Separation of styrene oligomers by reversed-phase (left) and size-exclusion chromatography (right) (Reprinted with permission from [121]. Copyright 1996 American Chemical Society). Conditions (left) column, molded poly(styrene-co-divinylbenzene) monolith, 50 mm x 8 mm i.d., mobile phase, linear gradient from 60 to 30% water in tetrahydrofuran within 20 min, flow rate 1 ml/min, injection volume 20 pi UV detection, 254 nm (right) series of four 300 mm x 7.5 mm i.d. PL Gel columns (100 A, 500 A, 105 A, and Mixed C), mobile phase tetrahydrofuran, flow rate, 1 ml/min injection volume 100 pi, toluene added as a flow marker, UV detection, 254 nm temperature 25 °C,peak numbers correspond to the number of styrene units in the oligomers...

A variety of procedures were utilized to analyze this reaction mixture and to characterize a,10-diaminopolystyrene. Thin layer chromatographic analysis using toluene as eluent exhibited three spots with Rf values of 0.85, 0.09, and 0.05 which corresponded to polystyrene, poly(styryl)amine and a,w-diaminopolystyrene (see Figure 1). Pure samples of each of these products were obtained by silica gel column Chromatography of the crude reaction mixture initially using toluene as eluent [for polystyrene and poly(styryl)amine] followed by a methanol/toluene mixture (5/100 v/v) for the diamine. Size-exclusion chromatography could not be used to characterize the diamine since no peak was observed for this material, apparently because of the complication of physical adsorption to the column packing material. Therefore, the dibenzoyl derivative (eq. 5) was prepared and used for most of the analytical characterizations. 

Murgasova, R. Hercules, D.M. Quantitative Characterization of a Polysty-rene/Poly(a-methylstyrene) Blend by MALDI-MS and Size-Exclusion Chromatography. Anal. Chem. 2003, 75, 3744-3750. 

HPMA [36] and a vinyl metal-chelating monomer A-(A/, A/ -dicarboxy-methylaminopropyl)methacrylamide synthesized [35]. Chemical structures of HPMA and DAMA are given in Figure 4. Poly(HPMA-co-DAMA) was prepared by free radical copolymerization in methanol with AIBN as initiator. Molecular weight distribution was determined by size exclusion chromatography and content of side-chain carboxylic group by acid-base titration. 

Thin-layer chromatography (75) and sodium dodecylsulfate-(poly)acrylamide gel electrophoresis (SDS-PAGE) are helpful for analyses of the lipid and protein composition, respectively. Size-exclusion chromatography allows estimation of the size distribution of the (proteo)liposomes and crude fractionation of the material as reviewed in Ref. 76. Accurate determinations of size distributions require analyses by static or dynamic... 

Molecular weight of poly(NAM-co-NAS) is determined by size exclusion chromatography (SEC) analysis. The eluent used is a DMF including 50 mM LiBr at a flow rate of 0.5 mL/min see Table 1). 

The solution behavior of poly(amic acids) was until recently, probably the least understood aspect of the soluble polyimide precursor. However, the advent of sophisticated laser light scattering and size exclusion chromatography instrumentation has allowed elucidation of the solution behavior of poly(amic adds). In the early days of polyimide chemistry, when most molecular weight characterization was based on viscosity determinations, a decrease in viscosity was associated with molecular weight degradation [15, 28, 29]. Upon combination of the two monomers an increase in the viscosity to the stoichiometric equivalence point is observed, followed by a decrease in the solution viscosity as a... 

The chemical imidization of poly(amic alkyl esters) was only reported very recently [59], although reports in the literature claim chemical imidization with a traditional acetic anhydride/pyridine mixture [87]. The chemical imidization of poly(amic alkyl esters) is based on the observation that PMDA/ODA based poly(amic ethyl ester) samples, when formulated at low concentrations for size exclusion chromatography, precipitated upon standing overnight [88]. Distillation of the NMP from phosphorus pentoxide to remove low levels of methyl-amine, a known impurity in this particular solvent, eliminated this unusual behavior. The precipitated polymer had significant levels of imidization as evidenced by IR. Apparently, organic bases, such as alkyl amines, were able to catalyze the conversion of amic alkyl esters to the corresponding imide. 

Dextrans are bacterial and yeast polysaccharides made up of (a 1—>6)-linked poly-D-glucose all have (al—>3) branches, and some also have (al—>2) or (al—>4) branches. Dental plaque, formed by bacteria growing on the surface of teeth, is rich in dextrans. Synthetic dextrans are used in several commercial products (for example, Sephadex) that serve in the fractionation of proteins by size-exclusion chromatography (see Fig. 3-18b). The dextrans in these products are chemically cross-linked to form insoluble materials of various porosities, admitting macromolecules of various sizes. 

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