Measurement by gel permeation chromatography

Measurement by gel permeation chromatography in 0.2 M phosphate buffer pH 7.0 with polystyrenesulfate or polyethylene glycols ([5] in the case of aureobasidium sp. A-91) as molecular weight standards. Data processing as de.scribed in Ref. [II]. 

Molecular weights were measured by gel permeation chromatography on a Perkin-Elmer Series 10 Liquid Chromatograph using tetrahydro-furan as solvent and refractive index as the detection mode. Standards were polystyrene, and reported molecular weights for the poly-siloxanes do not include a correction. 

It was found from the absorption spectrum that 1.1 % of the incident photons were absorbed at 2537 A by a PMMA film of 0.5 ym thickness (Fig. 5). The molecular weight distribution and the average molecular weight of the coated polymer which was irradiated for the least irradiation time required for the dissolution of polymer coating in the developer were measured by gel-permeation chromatography (Fig. 7). 

Molecular weight and molecular weight distributions of the samples were measured by gel permeation chromatography (GPC). The molecular weight of the polymers was controlled by changing polymerization conditions from 6.6 x 103 to 3.7 x 105 (2). The molecular weight distribution (Mu,/Mn) was from 2.2 to 4.3 (2). 

Molecular Weight Distribution. The ratio of weight-average molecular weight to number-average molecular weight of PET obtained by the addition of the chain extenders measured by gel permeation chromatography is shown in Table V. 

The filtrate was evaporated to dryness on the water bath. The fractions were, in individual cases, examined chemically and spectrophoto-metrically, and their molecular weights were measured by gel-permeation chromatography. 

Infrared spectra of polymer films were obtained on a Hitachi 260-10 Spectrometer. The films were formed from polymer solutions on NaCl discs. Molecular weight distributions were measured by gel permeation chromatography (GPC) using a Hitachi 635 Liquid Chromatograph equipped with Shodex A-80M, A-802 and A-801 GPC... 

Figure 5.30. Adsorption fractionation of a polydisperse sample as calculated from the SF model (a) and as measured by gel permeation chromatography (b))). The calculations apply to a Schultz-Flory distribution with = 2.05 ), the experiments to the...

Values of Mn were measured by gel permeation chromatography. The reaction was carried out at 30 °C. 

Note The reactions were carried out in toluene at 30 °C for 24 h ([M]o = 0.50 M [catalyst] = [cocatalyst] = 10 mM). Practically no or very little polymers were formed with Nb or Ta catalysts. "Values of Mw were measured by gel permeation chromatography. The reaction was carried out in CCI4. 

Synthesis of P(CMS-2VN), aiming at Dg =1 p. C / cm2 sensitivity, was carried out by ordinary radical polymerization in an inert-gas-filled flask with stirring (60 °C, 5 hrs.). The polymer after fractionation was Mw = 7.8 x 10-5, and polydispersivity Mw /Mn = 1.3 (as measured by gel permeation chromatography). The mole fractions in the polymer were found to be 9 mole % of CMS and 91 mole % 2VN ( as determined by elemental analysis). These values are very close to the mole fractions in the feed. The polymer was dissolved in xylene (5 wt.%), spin-coated (2000 rpm) and prebaked (100 °C for 30 min) to get uniform 0.5 jl m-thick-films on Si substrate. Pattern delineation was made by a 3EOL 3BX-5A (20 kV acceleration) electron beam exposure system without proximity corrections. Images were developed by dipping in 1,1,2,2-... 

The system styrene-acrylonitrile copolymer (SAN) 28% acrylonitrile/ poly (methyl methacrylate) exhibits thermodynamic solubility relationships adequate for studying phase transition phenomena. The molecular weight properties of the polymers used in this study (Table III) were measured by gel permeation chromatography. The cloud-point curve for binary mixtures of these two polymers was determined by a technique developed previously (10). 

The properties selected for evaluating the resins produced were internal bond strength, formaldehyde content measured by the perforator method, and the fraction of insoluble aggregates (FIA) measured by Gel Permeation Chromatography (GPC)/Size Exclusion Chromatography (SEC). However, for all the resins pro-... 

The number average molecular weight (MJ was measured by vapour pressure osmometer weight average molecular weight (M ) was measured by gel permeation chromatography ... 

As measured by gel permeation chromatography (GPC) versus polystyrene standards. Insoluble in GPC solvents. 

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